The current Branch History Rolling Buffer (BHRB) code does not check
for any privilege levels before updating the data from BHRB. This
could leak kernel addresses to userspace even when profiling only with
userspace privileges. Add proper checks to prevent it.
pwmX_mode is defined in the ABI as 0=DC mode, 1=pwm mode. The chip
register bit is set to 1 for DC mode. This got mixed up, and writing
1 into pwmX_mode resulted in DC mode enabled. Fix it up by using
the ABI definition throughout the driver for consistency.
Carlo Pisani noticed that his C3600 workstation behaved unstable during heavy
I/O on the PCI bus with a VIA VT6421 IDE/SATA PCI card.
To avoid such instability, this patch switches the LBA PCI bus from Hard Fail
mode into Soft Fail mode. In this mode the bus will return -1UL for timed out
MMIO transactions, which is exactly how the x86 (and most other architectures)
PCI busses behave.
This patch is based on a proposal by Grant Grundler and Kyle McMartin 10
years ago:
https://www.spinics.net/lists/linux-parisc/msg01027.html
As of commit 205e1b7f51e4 ("dma-mapping: warn when there is no
coherent_dma_mask") the Freescale FEC driver is issuing the following
warning on driver initialization on ColdFire systems:
It is not fatal, the driver and the system continue to function normally.
As per the warning the coherent_dma_mask is not set on this device.
There is nothing special about the DMA memory coherency on this hardware
so we can just set the mask to 32bits in the platform data for the FEC
ethernet devices.
In mpic_physmask() we loop over all CPUs up to 32, then get the hard
SMP processor id of that CPU.
Currently that's possibly walking off the end of the paca array, but
in a future patch we will change the paca array to be an array of
pointers, and in that case we will get a NULL for missing CPUs and
oops. eg:
Unable to handle kernel paging request for data at address 0x88888888888888b8
Faulting instruction address: 0xc00000000004e380
Oops: Kernel access of bad area, sig: 11 [#1]
...
NIP .mpic_set_affinity+0x60/0x1a0
LR .irq_do_set_affinity+0x48/0x100
Fix it by checking the CPU is possible, this also fixes the code if
there are gaps in the CPU numbering which probably never happens on
mpic systems but who knows.
Debugged-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If acpi_id is == nr_acpi_bits, then we access one element beyond the end
of the acpi_psd[] array or we set one bit beyond the end of the bit map
when we do __set_bit(acpi_id, acpi_id_present);
Fixes: 59a568029181 ("xen/acpi-processor: C and P-state driver that uploads said data to hypervisor.") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Joao Martins <joao.m.martins@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
While running btrfs/011, I hit the following lockdep splat.
This is the important bit:
pcpu_alloc+0x1ac/0x5e0
__percpu_counter_init+0x4e/0xb0
btrfs_init_fs_root+0x99/0x1c0 [btrfs]
btrfs_get_fs_root.part.54+0x5b/0x150 [btrfs]
resolve_indirect_refs+0x130/0x830 [btrfs]
find_parent_nodes+0x69e/0xff0 [btrfs]
btrfs_find_all_roots_safe+0xa0/0x110 [btrfs]
btrfs_find_all_roots+0x50/0x70 [btrfs]
btrfs_qgroup_prepare_account_extents+0x53/0x90 [btrfs]
btrfs_commit_transaction+0x3ce/0x9b0 [btrfs]
The percpu_counter_init call in btrfs_alloc_subvolume_writers
uses GFP_KERNEL, which we can't do during transaction commit.
This switches it to GFP_NOFS.
========================================================
WARNING: possible irq lock inversion dependency detected
4.12.14-kvmsmall #8 Tainted: G W
--------------------------------------------------------
kswapd0/50 just changed the state of lock:
(&delayed_node->mutex){+.+.-.}, at: [<ffffffffc06994fa>] __btrfs_release_delayed_node+0x3a/0x1f0 [btrfs]
but this lock took another, RECLAIM_FS-unsafe lock in the past:
(pcpu_alloc_mutex){+.+.+.}
and interrupts could create inverse lock ordering between them.
other info that might help us debug this:
Chain exists of:
&delayed_node->mutex --> &found->groups_sem --> pcpu_alloc_mutex
Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Liu Bo <bo.liu@linux.alibaba.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When logging an inode, at tree-log.c:copy_items(), if we call
btrfs_next_leaf() at the loop which checks for the need to log holes, we
need to make sure copy_items() returns the value 1 to its caller and
not 0 (on success). This is because the path the caller passed was
released and is now different from what is was before, and the caller
expects a return value of 0 to mean both success and that the path
has not changed, while a return value of 1 means both success and
signals the caller that it can not reuse the path, it has to perform
another tree search.
Even though this is a case that should not be triggered on normal
circumstances or very rare at least, its consequences can be very
unpredictable (especially when replaying a log tree).
Fixes: 16e7549f045d ("Btrfs: incompatible format change to remove hole extents") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
====================
kernel/debug/debug_core.c: In function ‘kgdb_cpu_enter’:
./arch/sparc/include/asm/cmpxchg_64.h:55:22: warning: value computed is not used [-Wunused-value]
#define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
./arch/sparc/include/asm/atomic_64.h:86:30: note: in expansion of macro ‘xchg’
#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
^~~~
kernel/debug/debug_core.c:508:4: note: in expansion of macro ‘atomic_xchg’
atomic_xchg(&kgdb_active, cpu);
^~~~~~~~~~~
====================
Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Exit to userspace with KVM_INTERNAL_ERROR_EMULATION if we encounter
an exception in Protected Mode while emulating guest due to invalid
guest state. Unlike Big RM, KVM doesn't support emulating exceptions
in PM, i.e. PM exceptions are always injected via the VMCS. Because
we will never do VMRESUME due to emulation_required, the exception is
never realized and we'll keep emulating the faulting instruction over
and over until we receive a signal.
Exit to userspace iff there is a pending exception, i.e. don't exit
simply on a requested event. The purpose of this check and exit is to
aid in debugging a guest that is in all likelihood already doomed.
Invalid guest state in PM is extremely limited in normal operation,
e.g. it generally only occurs for a few instructions early in BIOS,
and any exception at this time is all but guaranteed to be fatal.
Non-vectored interrupts, e.g. INIT, SIPI and SMI, can be cleanly
handled/emulated, while checking for vectored interrupts, e.g. INTR
and NMI, without hitting false positives would add a fair amount of
complexity for almost no benefit (getting hit by lightning seems
more likely than encountering this specific scenario).
Add a WARN_ON_ONCE to vmx_queue_exception() if we try to inject an
exception via the VMCS and emulation_required is true.
We can get rid of it be the "traditional" means of adding an
update_rq_clock() call after acquiring the rq->lock in
do_sched_rt_period_timer().
The case for the RT task throttling (which this workload also hits)
can be ignored in that the skip_update call is actually bogus and
quite the contrary (the request bits are removed/reverted).
By setting RQCF_UPDATED we really don't care if the skip is happening
or not and will therefore make the assert_clock_updated() check happy.
do_chunk_alloc implements a loop checking whether there is a pending
chunk allocation and if so causes the caller do loop. Generally this
loop is executed only once, however testing with btrfs/072 on a single
core vm machines uncovered an extreme case where the system could loop
indefinitely. This is due to a missing cond_resched when loop which
doesn't give a chance to the previous chunk allocator finish its job.
The fix is to simply add the missing cond_resched.
Fixes: 6d74119f1a3e ("Btrfs: avoid taking the chunk_mutex in do_chunk_alloc") Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
0, 1 and <0 can be returned by btrfs_next_leaf(), and when <0 is
returned, path->nodes[0] could be NULL, log_dir_items lacks such a
check for <0 and we may run into a null pointer dereference panic.
Fixes: e02119d5a7b4 ("Btrfs: Add a write ahead tree log to optimize synchronous operations") Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If errors were returned by btrfs_next_leaf(), replay_dir_deletes needs
to bail out, otherwise @ret would be forced to be 0 after 'break;' and
the caller won't be aware of it.
Fixes: e02119d5a7b4 ("Btrfs: Add a write ahead tree log to optimize synchronous operations") Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When page_mapping() is called and the mapping is dereferenced in
page_evicatable() through shrink_active_list(), it is possible for the
inode to be truncated and the embedded address space to be freed at the
same time. This may lead to the following race.
CPU1 CPU2
truncate(inode) shrink_active_list()
... page_evictable(page)
truncate_inode_page(mapping, page);
delete_from_page_cache(page)
spin_lock_irqsave(&mapping->tree_lock, flags);
__delete_from_page_cache(page, NULL)
page_cache_tree_delete(..)
... mapping = page_mapping(page);
page->mapping = NULL;
...
spin_unlock_irqrestore(&mapping->tree_lock, flags);
page_cache_free_page(mapping, page)
put_page(page)
if (put_page_testzero(page)) -> false
- inode now has no pages and can be freed including embedded address_space
mapping_unevictable(mapping)
test_bit(AS_UNEVICTABLE, &mapping->flags);
- we've dereferenced mapping which is potentially already free.
Similar race exists between swap cache freeing and page_evicatable()
too.
The address_space in inode and swap cache will be freed after a RCU
grace period. So the races are fixed via enclosing the page_mapping()
and address_space usage in rcu_read_lock/unlock(). Some comments are
added in code to make it clear what is protected by the RCU read lock.
Link: http://lkml.kernel.org/r/20180212081227.1940-1-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Minchan Kim <minchan@kernel.org> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes a corner case for KSM. When two pages belong or
belonged to the same transparent hugepage, and they should be merged,
KSM fails to split the page, and therefore no merging happens.
This bug can be reproduced by:
* making sure ksm is running (in case disabling ksmtuned)
* enabling transparent hugepages
* allocating a THP-aligned 1-THP-sized buffer
e.g. on amd64: posix_memalign(&p, 1<<21, 1<<21)
* filling it with the same values
e.g. memset(p, 42, 1<<21)
* performing madvise to make it mergeable
e.g. madvise(p, 1<<21, MADV_MERGEABLE)
* waiting for KSM to perform a few scans
The expected outcome is that the all the pages get merged (1 shared and
the rest sharing); the actual outcome is that no pages get merged (1
unshared and the rest volatile)
The reason of this behaviour is that we increase the reference count
once for both pages we want to merge, but if they belong to the same
hugepage (or compound page), the reference counter used in both cases is
the one of the head of the compound page. This means that
split_huge_page will find a value of the reference counter too high and
will fail.
This patch solves this problem by testing if the two pages to merge
belong to the same hugepage when attempting to merge them. If so, the
hugepage is split safely. This means that the hugepage is not split if
not necessary.
Link: http://lkml.kernel.org/r/1521548069-24758-1-git-send-email-imbrenda@linux.vnet.ibm.com Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com> Co-authored-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The datasheet specifies a 3uS pause after performing a software
reset. The default implementation of genphy_soft_reset() does not
provide this, so implement soft_reset with the needed pause.
Signed-off-by: Esben Haabendal <eha@deif.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If a recursive IOP_RESET is invoked, usually due to the eh_thread
handling errors after the first reset, be sure we flag that the command
thread has been stopped to avoid an Oops of the form;
Forcing the log to disk after reading the agf is wrong, we might be
calling xfs_log_force with XFS_LOG_SYNC with a metadata lock held.
This can cause a deadlock when racing a fstrim with a filesystem
shutdown.
The deadlock has been identified due a miscalculation bug in device-mapper
dm-thin, which returns lack of space to its users earlier than the device itself
really runs out of space, changing the device-mapper volume into an error state.
The problem happened while filling the filesystem with a single file,
triggering the bug in device-mapper, consequently causing an IO error
and shutting down the filesystem.
If such file is removed, and fstrim executed before the XFS finishes the
shut down process, the fstrim process will end up holding the buffer
lock, and going to sleep on the cil wait queue.
At this point, the shut down process will try to wake up all the threads
waiting on the cil wait queue, but for this, it will try to hold the
same buffer log already held my the fstrim, locking up the filesystem.
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We can't just use scsi_cd() to get the scsi_cd structure, we have
to grab a live reference to the device. For both callbacks, we're
not inside an open where we already hold a reference to the device.
This fixes device removal/addition under concurrent device access,
which otherwise could result in the below oops.
Calling swapon() on a zero length swap file on SSD can lead to a
divide-by-zero.
Although creating such files isn't possible with mkswap and they woud be
considered invalid, it would be better for the swapon code to be more
robust and handle this condition gracefully (return -EINVAL).
Especially since the fix is small and straightforward.
To help with wear leveling on SSD, the swapon syscall calculates a
random position in the swap file using modulo p->highest_bit, which is
set to maxpages - 1 in read_swap_header.
If the swap file is zero length, read_swap_header sets maxpages=1 and
last_page=0, resulting in p->highest_bit=0 and we divide-by-zero when we
modulo p->highest_bit in swapon syscall.
This can be prevented by having read_swap_header return zero if
last_page is zero.
Link: http://lkml.kernel.org/r/5AC747C1020000A7001FA82C@prv-mh.provo.novell.com Signed-off-by: Thomas Abraham <tabraham@suse.com> Reported-by: <Mark.Landis@Teradata.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
proc_sys_link_fill_cache() does not take currently unregistering sysctl
tables into account, which might result into a page fault in
sysctl_follow_link() - add a check to fix it.
This bug has been present since v3.4.
Link: http://lkml.kernel.org/r/20180228013506.4915-1-danilokrummrich@dk-develop.de Fixes: 0e47c99d7fe25 ("sysctl: Replace root_list with links between sysctl_table_sets") Signed-off-by: Danilo Krummrich <danilokrummrich@dk-develop.de> Acked-by: Kees Cook <keescook@chromium.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: "Luis R . Rodriguez" <mcgrof@kernel.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When responding to a debug trap (breakpoint) in userspace, the
kernel's trap handler raised SIGTRAP but returned from the trap via a
code path that ignored pending signals, resulting in an infinite loop
re-executing the trapping instruction.
In some situation vlan packets do not have ethernet headers. One example
is packets from tun devices. Users can specify vlan protocol in tun_pi
field instead of IP protocol, and skb_vlan_untag() attempts to untag such
packets.
skb_vlan_untag() (more precisely, skb_reorder_vlan_header() called by it)
however did not expect packets without ethernet headers, so in such a case
size argument for memmove() underflowed and triggered crash.
We don't need to copy headers for packets which do not have preceding
headers of vlan headers, so skip memmove() in that case.
Fixes: 4bbb3e0e8239 ("net: Fix vlan untag for bridge and vlan_dev with reorder_hdr off") Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
llc_conn_send_pdu() pushes the skb into write queue and
calls llc_conn_send_pdus() to flush them out. However, the
status of dev_queue_xmit() is not returned to caller,
in this case, llc_conn_state_process().
llc_conn_state_process() needs hold the skb no matter
success or failure, because it still uses it after that,
therefore we should hold skb before dev_queue_xmit() when
that skb is the one being processed by llc_conn_state_process().
For other callers, they can just pass NULL and ignore
the return value as they are.
Reported-by: Noam Rathaus <noamr@beyondsecurity.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Giuseppe Lippolis <giu.lippolis@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
BroadMobi BM806U is an Qualcomm MDM9225 based 3G/4G modem.
Tested hardware BM806U is mounted on D-Link DWR-921-C3 router.
The USB id is added to qmi_wwan.c to allow QMI communication with
the BM806U.
Tested on 4.14 kernel and OpenWRT.
Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
DHCP connectivity issues can currently occur if the following conditions
are met:
1) A DHCP packet from a client to a server
2) This packet has a multicast destination
3) This destination has a matching entry in the translation table
(FF:FF:FF:FF:FF:FF for IPv4, 33:33:00:01:00:02/33:33:00:01:00:03
for IPv6)
4) The orig-node determined by TT for the multicast destination
does not match the orig-node determined by best-gateway-selection
In this case the DHCP packet will be dropped.
The "gateway-out-of-range" check is supposed to only be applied to
unicasted DHCP packets to a specific DHCP server.
In that case dropping the the unicasted frame forces the client to
retry via a broadcasted one, but now directed to the new best
gateway.
A DHCP packet with broadcast/multicast destination is already ensured to
always be delivered to the best gateway. Dropping a multicasted
DHCP packet here will only prevent completing DHCP as there is no
other fallback.
So far, it seems the unicast check was implicitly performed by
expecting the batadv_transtable_search() to return NULL for multicast
destinations. However, a multicast address could have always ended up in
the translation table and in fact is now common.
To fix this potential loss of a DHCP client-to-server packet to a
multicast address this patch adds an explicit multicast destination
check to reliably bail out of the gateway-out-of-range check for such
destinations.
The issue and fix were tested in the following three node setup:
- Line topology, A-B-C
- A: gateway client, DHCP client
- B: gateway server, hop-penalty increased: 30->60, DHCP server
- C: gateway server, code modifications to announce FF:FF:FF:FF:FF:FF
Without this patch, A would never transmit its DHCP Discover packet
due to an always "out-of-range" condition. With this patch,
a full DHCP handshake between A and B was possible again.
For multicast frames AP isolation is only supposed to be checked on
the receiving nodes and never on the originating one.
Furthermore, the isolation or wifi flag bits should only be intepreted
as such for unicast and never multicast TT entries.
By injecting flags to the multicast TT entry claimed by a single
target node it was verified in tests that this multicast address
becomes unreachable, leading to packet loss.
Omitting the "src" parameter to the batadv_transtable_search() call
successfully skipped the AP isolation check and made the target
reachable again.
Fixes: 1d8ab8d3c176 ("batman-adv: Modified forwarding behaviour for multicast packets") Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue> Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Alexander reported a use of uninitialized memory in __mpol_equal(),
which is caused by incorrect use of preferred_node.
When mempolicy in mode MPOL_PREFERRED with flags MPOL_F_LOCAL, it uses
numa_node_id() instead of preferred_node, however, __mpol_equal() uses
preferred_node without checking whether it is MPOL_F_LOCAL or not.
[akpm@linux-foundation.org: slight comment tweak] Link: http://lkml.kernel.org/r/4ebee1c2-57f6-bcb8-0e2d-1833d1ee0bb7@huawei.com Fixes: fc36b8d3d819 ("mempolicy: use MPOL_F_LOCAL to Indicate Preferred Local Policy") Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com> Reported-by: Alexander Potapenko <glider@google.com> Tested-by: Alexander Potapenko <glider@google.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Don't hardcode a MTU value on vti tunnel initialization,
ip_tunnel_newlink() is able to deal with this already. See also
commit ffc2b6ee4174 ("ip_gre: fix IFLA_MTU ignored on NEWLINK").
Fixes: 1181412c1a67 ("net/ipv4: VTI support new module for ip_vti.") Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Acked-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This re-introduces the effect of commit a32452366b72 ("vti4:
Don't count header length twice.") which was accidentally
reverted by merge commit f895f0cfbb77 ("Merge branch 'master' of
git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec").
The commit message from Steffen Klassert said:
We currently count the size of LL_MAX_HEADER and struct iphdr
twice for vti4 devices, this leads to a wrong device mtu.
The size of LL_MAX_HEADER and struct iphdr is already counted in
ip_tunnel_bind_dev(), so don't do it again in vti_tunnel_init().
And this is still the case now: ip_tunnel_bind_dev() already
accounts for the header length of the link layer (not
necessarily LL_MAX_HEADER, if the output device is found), plus
one IP header.
For example, with a vti device on top of veth, with MTU of 1500,
the existing implementation would set the initial vti MTU to
1332, accounting once for LL_MAX_HEADER (128, included in
hard_header_len by vti) and twice for the same IP header (once
from hard_header_len, once from ip_tunnel_bind_dev()).
It should instead be 1480, because ip_tunnel_bind_dev() is able
to figure out that the output device is veth, so no additional
link layer header is attached, and will properly count one
single IP header.
The existing issue had the side effect of avoiding PMTUD for
most xfrm policies, by arbitrarily lowering the initial MTU.
However, the only way to get a consistent PMTU value is to let
the xfrm PMTU discovery do its course, and commit d6af1a31cc72
("vti: Add pmtu handling to vti_xmit.") now takes care of local
delivery cases where the application ignores local socket
notifications.
Fixes: b9959fd3b0fa ("vti: switch to new ip tunnel code") Fixes: f895f0cfbb77 ("Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec") Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Acked-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Checking for 0 is insufficient: when an SKB without a batadv header, but
with a VLAN header is received, hdr_size will be 4, making the following
code interpret the Ethernet header as a batadv header.
Fixes: be1db4f6615b ("batman-adv: make the Distributed ARP Table vlan aware") Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net> Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When we have a bridge with vlan_filtering on and a vlan device on top of
it, packets would be corrupted in skb_vlan_untag() called from
br_dev_xmit().
The problem sits in skb_reorder_vlan_header() used in skb_vlan_untag(),
which makes use of skb->mac_len. In this function mac_len is meant for
handling rx path with vlan devices with reorder_header disabled, but in
tx path mac_len is typically 0 and cannot be used, which is the problem
in this case.
The current code even does not properly handle rx path (skb_vlan_untag()
called from __netif_receive_skb_core()) with reorder_header off actually.
In rx path single tag case, it works as follows:
- Before skb_reorder_vlan_header()
mac_header data
v v
+-------------------+-------------+------+----
| ETH | VLAN | ETH |
| ADDRS | TPID | TCI | TYPE |
+-------------------+-------------+------+----
<-------- mac_len --------->
<------------->
to be removed
- After skb_reorder_vlan_header()
mac_header data
v v
+-------------------+------+----
| ETH | ETH |
| ADDRS | TYPE |
+-------------------+------+----
<-------- mac_len --------->
This is ok, but in rx double tag case, it corrupts packets:
- Before skb_reorder_vlan_header()
mac_header data
v v
+-------------------+-------------+-------------+------+----
| ETH | VLAN | VLAN | ETH |
| ADDRS | TPID | TCI | TPID | TCI | TYPE |
+-------------------+-------------+-------------+------+----
<--------------- mac_len ---------------->
<------------->
should be removed
<--------------------------->
actually will be removed
- After skb_reorder_vlan_header()
mac_header data
v v
+-------------------+------+----
| ETH | ETH |
| ADDRS | TYPE |
+-------------------+------+----
<--------------- mac_len ---------------->
So, two of vlan tags are both removed while only inner one should be
removed and mac_header (and mac_len) is broken.
skb_vlan_untag() is meant for removing the vlan header at (skb->data - 2),
so use skb->data and skb->mac_header to calculate the right offset.
Reported-by: Brandon Carpenter <brandon.carpenter@cypherpath.com> Fixes: a6e18ff11170 ("vlan: Fix untag operations of stacked vlans with REORDER_HEADER off") Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The last rule in the blob has next_entry offset that is same as total size.
This made "ebtables32 -A OUTPUT -d de:ad:be:ef:01:02" fail on 64 bit kernel.
Scatter-gather needs to be disabled when using dma_declare_coherent_memory
and HCD_LOCAL_MEM. Andrea Righi made the equivalent fix for EHCI drivers
in commit 4307a28eb01284 "USB: EHCI: fix NULL pointer dererence in HCDs
that use HCD_LOCAL_MEM".
The following NULL pointer WARN_ON_ONCE triggered with OHCI drivers:
Fixing arbitrary kernel leak in case FBIOGETCMAP_SPARC in
sbusfb_ioctl_helper().
'index' is defined as an int in sbusfb_ioctl_helper().
We retrieve this from the user:
if (get_user(index, &c->index) ||
__get_user(count, &c->count) ||
__get_user(ured, &c->red) ||
__get_user(ugreen, &c->green) ||
__get_user(ublue, &c->blue))
return -EFAULT;
and then we use 'index' in the following way:
red = cmap->red[index + i] >> 8;
green = cmap->green[index + i] >> 8;
blue = cmap->blue[index + i] >> 8;
This is a classic information leak vulnerability. 'index' should be
an unsigned int, given its usage above.
This patch is straight-forward; it changes 'index' to unsigned int
in two switch-cases: FBIOGETCMAP_SPARC && FBIOPUTCMAP_SPARC.
This commit reads the disk's old state and combines it with the device
disk-reported state rather than unconditionally marking it as RW.
Reported-by: Li Ning <lining916740672@icloud.com> Signed-off-by: Jeremy Cline <jeremy@jcline.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Without pm_runtime_{get,put}_sync calls in place, reading
vbus status via /sys causes the following error:
Unhandled fault: external abort on non-linefetch (0x1028) at 0xfa0ab060
pgd = b333e822
[fa0ab060] *pgd=48011452(bad)
[<c05261b0>] (musb_default_readb) from [<c0525bd0>] (musb_vbus_show+0x58/0xe4)
[<c0525bd0>] (musb_vbus_show) from [<c04c0148>] (dev_attr_show+0x20/0x44)
[<c04c0148>] (dev_attr_show) from [<c0259f74>] (sysfs_kf_seq_show+0x80/0xdc)
[<c0259f74>] (sysfs_kf_seq_show) from [<c0210bac>] (seq_read+0x250/0x448)
[<c0210bac>] (seq_read) from [<c01edb40>] (__vfs_read+0x1c/0x118)
[<c01edb40>] (__vfs_read) from [<c01edccc>] (vfs_read+0x90/0x144)
[<c01edccc>] (vfs_read) from [<c01ee1d0>] (SyS_read+0x3c/0x74)
[<c01ee1d0>] (SyS_read) from [<c0106fe0>] (ret_fast_syscall+0x0/0x54)
Solution was suggested by Tony Lindgren <tony@atomide.com>.
Signed-off-by: Merlijn Wajer <merlijn@wizzup.org> Acked-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Bin Liu <b-liu@ti.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Descriptor rings were not initialized at zero when allocated
When area contained garbage data, it caused skb_over_panic in
e1000_clean_rx_irq (if data had E1000_RXD_STAT_DD bit set)
This patch makes use of dma_zalloc_coherent to make sure the
ring is memset at 0 to prevent the area from containing garbage.
Following is the signature of the panic:
IODDR0@0.0: skbuff: skb_over_panic: text:80407b20 len:64010 put:64010 head:ab46d800 data:ab46d842 tail:0xab47d24c end:0xab46df40 dev:eth0
IODDR0@0.0: BUG: failure at net/core/skbuff.c:105/skb_panic()!
IODDR0@0.0: Kernel panic - not syncing: BUG!
IODDR0@0.0:
IODDR0@0.0: Process swapper/0 (pid: 0, threadinfo=81728000, task=8173cc00 ,cpu: 0)
IODDR0@0.0: SP = <815a1c0c>
IODDR0@0.0: Stack: 00000001
IODDR0@0.0: b2d89800815e33ac
IODDR0@0.0: ea73c04000000001
IODDR0@0.0: 600400030000fa0a
IODDR0@0.0: 00000002
IODDR0@0.0:
IODDR0@0.0: 804540c0815a1c70
IODDR0@0.0: b2744000602ac070
IODDR0@0.0: 815a1c44b2d89800
IODDR0@0.0: 8173cc00815a1c08
IODDR0@0.0:
IODDR0@0.0: 00000006
IODDR0@0.0: 815a1b5000000000
IODDR0@0.0: 8007943400000001
IODDR0@0.0: ab46df40b2744000
IODDR0@0.0: b2d89800
IODDR0@0.0:
IODDR0@0.0: 0000fa0a8045745c
IODDR0@0.0: 815a1c880000fa0a
IODDR0@0.0: 80407b20b2789f80
IODDR0@0.0: 0000000580407b20
IODDR0@0.0:
IODDR0@0.0:
IODDR0@0.0: Call Trace:
IODDR0@0.0: [<804540bc>] skb_panic+0xa4/0xa8
IODDR0@0.0: [<80079430>] console_unlock+0x2f8/0x6d0
IODDR0@0.0: [<80457458>] skb_put+0xa0/0xc0
IODDR0@0.0: [<80407b1c>] e1000_clean_rx_irq+0x2dc/0x3e8
IODDR0@0.0: [<80407b1c>] e1000_clean_rx_irq+0x2dc/0x3e8
IODDR0@0.0: [<804079c8>] e1000_clean_rx_irq+0x188/0x3e8
IODDR0@0.0: [<80407b1c>] e1000_clean_rx_irq+0x2dc/0x3e8
IODDR0@0.0: [<80468b48>] __dev_kfree_skb_any+0x88/0xa8
IODDR0@0.0: [<804101ac>] e1000e_poll+0x94/0x288
IODDR0@0.0: [<8046e9d4>] net_rx_action+0x19c/0x4e8
IODDR0@0.0: ...
IODDR0@0.0: Maximum depth to print reached. Use kstack=<maximum_depth_to_print> To specify a custom value (where 0 means to display the full backtrace)
IODDR0@0.0: ---[ end Kernel panic - not syncing: BUG!
Signed-off-by: Pierre-Yves Kerbrat <pkerbrat@kalray.eu> Signed-off-by: Marius Gligor <mgligor@kalray.eu> Tested-by: Aaron Brown <aaron.f.brown@intel.com> Reviewed-by: Alexander Duyck <alexander.h.duyck@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When autoneg is off, the .check_for_link callback functions clear the
get_link_status flag and systematically return a "pseudo-error". This means
that the link is not detected as up until the next execution of the
e1000_watchdog_task() 2 seconds later.
Fixes: 19110cfbb34d ("e1000e: Separate signaling for link check/link up") Signed-off-by: Benjamin Poirier <bpoirier@suse.com> Acked-by: Sasha Neftin <sasha.neftin@intel.com> Tested-by: Aaron Brown <aaron.f.brown@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When doing an incremental send of a filesystem with the no-holes feature
enabled, we end up issuing a write operation when using the no data mode
send flag, instead of issuing an update extent operation. Fix this by
issuing the update extent operation instead.
Trivial reproducer:
$ mkfs.btrfs -f -O no-holes /dev/sdc
$ mkfs.btrfs -f /dev/sdd
$ mount /dev/sdc /mnt/sdc
$ mount /dev/sdd /mnt/sdd
Current cleanup in the error path of xen_bind_pirq_msi_to_irq is
wrong. First of all there's an off-by-one in the cleanup loop, which
can lead to unbinding wrong IRQs.
Secondly IRQs not bound won't be freed, thus leaking IRQ numbers.
Note that there's no need to differentiate between bound and unbound
IRQs when freeing them, __unbind_from_irq will deal with both of them
correctly.
Fixes: 4892c9b4ada9f9 ("xen: add support for MSI message groups") Reported-by: Hooman Mirhadi <mirhadih@amazon.com> Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: Amit Shah <aams@amazon.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The link to the pdf containing the algorithm description is now a
dead link; it seems http://www.ifp.illinois.edu/~srikant/ has been
moved to https://sites.google.com/a/illinois.edu/srikant/ and none of
the original papers can be found there...
I have replaced it with the only working copy I was able to find.
However, this seems to only be a *cached* version, so I am unsure
exactly how reliable that link can be expected to remain over time
and have decided against using that one.
Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 128bb975dc3c ("ip6_gre: init dev->mtu and dev->hard_header_len
correctly") fixed IFLA_MTU ignored on NEWLINK for ip6_gre. The same
mtu fix is also needed for sit.
Note that dev->hard_header_len setting for sit works fine, no need to
fix it. sit is actually ipv4 tunnel, it can't call ip6_tnl_change_mtu
to set mtu.
Reported-by: Jianlin Shi <jishi@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
All the crash issue happened when a bypass IO coming, in such scenario
s->iop.bio is pointed to the s->orig_bio. In search_free(), it finishes the
s->orig_bio by calling bio_complete(), and after that, s->iop.bio became
invalid, then kernel would crash when calling bio_put(). Maybe its upper
layer's faulty, since bio should not be freed before we calling bio_put(),
but we'd better calling bio_put() first before calling bio_complete() to
notify upper layer ending this bio.
This patch moves bio_complete() under bio_put() to avoid kernel crash.
[mlyle: fixed commit subject for character limits]
Reported-by: Matthias Ferdinand <bcache@mfedv.net> Tested-by: Matthias Ferdinand <bcache@mfedv.net> Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn> Reviewed-by: Michael Lyle <mlyle@lyle.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
r8152 driver handles TSO packets (limited to ~16KB) quite well,
but pretends each TSO logical packet is a single packet on the wire.
There is also some error since headers are accounted once, but
error rate is small enough that we do not care.
Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The error checks on freq for a negative error return always fails because
freq is unsigned and can never be negative. Fix this by making freq a
signed long.
Detected with Coccinelle:
drivers/clocksource/fsl_ftm_timer.c:287:5-9: WARNING: Unsigned expression
compared with zero: freq <= 0
drivers/clocksource/fsl_ftm_timer.c:291:5-9: WARNING: Unsigned expression
compared with zero: freq <= 0
Fixes: 2529c3a33079 ("clocksource: Add Freescale FlexTimer Module (FTM) timer support") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: kernel-janitors@vger.kernel.org Link: https://lkml.kernel.org/r/20180226113614.3092-1-colin.king@canonical.com Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A more sophisticated implementation could try to combine fragment checksums
when all fragments have CHECKSUM_COMPLETE and are split at even offsets.
For now, we just set ip_summed to CHECKSUM_NONE to avoid "hw csum failure"
warnings in the kernel log when fragmented frames are received. In
consequence, skb_pull_rcsum() can be replaced with skb_pull().
Note that in usual setups, packets don't reach batman-adv with
CHECKSUM_COMPLETE (I assume NICs bail out of checksumming when they see
batadv's ethtype?), which is why the log messages do not occur on every
system using batman-adv. I could reproduce this issue by stacking
batman-adv on top of a VXLAN interface.
Fixes: 610bfc6bc99b ("batman-adv: Receive fragmented packets and merge") Tested-by: Maximilian Wilhelm <max@sdn.clinic> Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net> Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
eth_type_trans() internally calls skb_pull(), which does not adjust the
skb checksum; skb_postpull_rcsum() is necessary to avoid log spam of the
form "bat0: hw csum failure" when packets with CHECKSUM_COMPLETE are
received.
Note that in usual setups, packets don't reach batman-adv with
CHECKSUM_COMPLETE (I assume NICs bail out of checksumming when they see
batadv's ethtype?), which is why the log messages do not occur on every
system using batman-adv. I could reproduce this issue by stacking
batman-adv on top of a VXLAN interface.
Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol") Tested-by: Maximilian Wilhelm <max@sdn.clinic> Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net> Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In handle_write_finished(), if r1_bio->bios[m] != NULL, it thinks
the corresponding conf->mirrors[m].rdev is also not NULL. But, it
is not always true.
Even if some io hold replacement rdev(i.e. rdev->nr_pending.count > 0),
raid1_remove_disk() can also set the rdev as NULL. That means,
bios[m] != NULL, but mirrors[m].rdev is NULL, resulting in NULL
pointer dereference in handle_write_finished and sync_request_write.
Returning -EINVAL when an ioctl is not implemented is a very
bad idea, as it is hard to distinguish from other error
contitions that an ioctl could lead. Replace it by its
right error code: -ENOTTY.
Similar to the ancient commit a5fe8e7695dc ("regulatory: add NUL
to alpha2"), add another byte to alpha2 in the request struct so
that when we use nla_put_string(), we don't overrun anything.
If an attempt is made to disable RX checksums, USB adapter is changed
but netdev->features is not, because smsc75xx_set_features() returns a
non zero value.
This throws errors from netdev_rx_csum_fault() :
<devname>: hw csum failure
Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Steve Glendinning <steve.glendinning@shawell.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When we terminate driver I/O (because we need to stop using a certain
channel path) we also need to ensure that a timer (which may have been
set up using ccw_device_start_timeout) is cleared.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a timeout occurs for users of ccw_device_start_timeout
we will stop the IO and call the drivers int handler with
the irb pointer set to ERR_PTR(-ETIMEDOUT). Sometimes
however we'd set the irb pointer to ERR_PTR(-EIO) which is
not intended. Just set the correct value in all codepaths.
Reported-by: Julian Wiedmann <jwi@linux.vnet.ibm.com> Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Continuing along with the fight against smp_read_barrier_depends() [1]
(or rather, against its improper use), add an unconditional barrier to
cmpxchg. This guarantees that dependency ordering is preserved when a
dependency is headed by an unsuccessful cmpxchg. As it turns out, the
change could enable further simplification of LKMM as proposed in [2].
In the case of 'recover', an r10bio with R10BIO_WriteError &
R10BIO_IsRecover will be progressed by handle_write_completed().
This function traverses all r10bio->devs[copies].
If devs[m].repl_bio != NULL, it thinks conf->mirrors[dev].replacement
is also not NULL. However, this is not always true.
When there is an rdev of raid10 has replacement, then each r10bio
->devs[m].repl_bio != NULL in conf->r10buf_pool. However, in 'recover',
even if corresponded replacement is NULL, it doesn't clear r10bio
->devs[m].repl_bio, resulting in replacement NULL deference.
This bug was introduced when replacement support for raid10 was
added in Linux 3.3.
As NeilBrown suggested:
Elsewhere the determination of "is this device part of the
resync/recovery" is made by resting bio->bi_end_io.
If this is end_sync_write, then we tried to write here.
If it is NULL, then we didn't try to write.
This ensures that mac80211 allocated management frames are properly
aligned, which makes copying them more efficient.
For instance, mt76 uses iowrite32_copy to copy beacon frames to beacon
template memory on the chip.
Misaligned 32-bit accesses cause CPU exceptions on MIPS and should be
avoided.
Signed-off-by: Felix Fietkau <nbd@nbd.name> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The tlv_len is u8, so we need to limit the size of the SDP URI. Enforce
this both in the NLA policy and in the code that performs the allocation
and copy, to avoid writing past the end of the allocated buffer.
Fixes: d9b8d8e19b073 ("NFC: llcp: Service Name Lookup netlink interface") Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When exposing data access through debugfs, the correct
debugfs_create_*() functions must be used, depending on data type.
Remove all casts from data pointers passed to debugfs_create_*()
functions, as such casts prevent the compiler from flagging bugs.
Correct all wrong usage:
- clk.rate is unsigned long, not u32,
- clk.flags is u8, not u32, which exposed the successive
clk.rate_offset and clk.src_offset fields.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Aaro Koskinen <aaro.koskinen@iki.fi> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For platform_suspend_ops, the finish call is too late to re-enable wake
irqs and we need re-enable wake irqs on wake call instead.
Otherwise noirq resume for devices has already happened. And then
dev_pm_disarm_wake_irq() has already disabled the dedicated wake irqs
when the interrupt triggers and the wake irq is never handled.
For devices that are already in PM runtime suspended state when we
enter suspend this means that a possible wake irq will never trigger.
And this can lead into a situation where a device has a pending padconf
wake irq, and the device will stay unresponsive to any further wake
irqs.
This issue can be easily reproduced by setting serial console log level
to zero, letting the serial console idle, and suspend the system from
an ssh terminal. Then try to wake up the system by typing to the serial
console.
Note that this affects only omap3 PRM interrupt as that's currently
the only omap variant that does anything in omap_pm_wake().
In general, for the wake irqs to work, the interrupt must have either
IRQF_NO_SUSPEND or IRQF_EARLY_RESUME set for it to trigger before
dev_pm_disarm_wake_irq() disables the wake irqs.
Reported-by: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Tero Kristo <t-kristo@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
and that assumes shost has been assigned with pci_set_drvdata().
However, pci_set_drvdata(pdev, shost) is done in aac_probe_one() far
after bailing out with error from calling the init function
((*aac_drivers[index].init)(aac)), and when the init function fails, no
error is returned from aac_probe_one() so PCI layer assumes there is
driver attached, and tries to shut it down later.
Fix it by returning error from aac_probe_one() when card-specific init
function fails.
This fixes reboot on my HP NetRAID-4M with dead battery.
Signed-off-by: Meelis Roos <mroos@linux.ee> Reviewed-by: Dave Carroll <david.carroll@microsemi.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Clang reports the following warning:
drivers/usb/gadget/udc/fsl_udc_core.c:1312:10: warning: address of array
'ep->name' will always evaluate to 'true' [-Wpointer-bool-conversion]
if (ep->name)
~~ ~~~~^~~~
It seems that the authors intention was to check if the ep has been
configured through struct_ep_setup. Check whether struct usb_ep name
pointer has been set instead.
Signed-off-by: Stefan Agner <stefan@agner.ch> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If there are multiple functions associated with a configuration, then
the UAC2 interfaces may not start at zero. Set the correct first
interface number in the association descriptor so that the audio
interfaces are enumerated correctly in this case.
Reviewed-by: Krzysztof Opasiak <k.opasiak@samsung.com> Signed-off-by: John Keeping <john@metanate.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We wanted to exit the loop with "div" set to zero, but instead, if we
don't hit the break then "div" is -1 when we finish the loop. It leads
to an array underflow a few lines later.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Acked-by: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a request times out we set the io_req flag BNX2FC_FLAG_IO_COMPL so
that if a subsequent completion comes in on that task ID we will ignore
it. The issue is that in the check for this flag there is a missing
return so we will continue to process a request which may have already
been returned to the ownership of the SCSI layer. This can cause
unpredictable results.
Solution is to add in the missing return.
[mkp: typo plus title shortening]
Signed-off-by: Chad Dupuis <chad.dupuis@cavium.com> Reviewed-by: Laurence Oberman <loberman@redhat.com> Tested-by: Laurence Oberman <loberman@redhat.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This could be fixed with printk_deferred() but that might lessen its
usefulness for debugging. So change it to pr_devel to keep it out of
production kernels. Developers working on gic-v3 can enable it as
needed in their kernels.
Signed-off-by: Mark Salter <msalter@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
I attach a back-end device to a cache set, and the cache set is not
registered yet, this back-end device did not attach successfully, and no
error returned:
[root]# echo 87859280-fec6-4bcc-20df7ca8f86b > /sys/block/sde/bcache/attach
[root]#
In sysfs_attach(), the return value "v" is initialized to "size" in
the beginning, and if no cache set exist in bch_cache_sets, the "v" value
would not change any more, and return to sysfs, sysfs regard it as success
since the "size" is a positive number.
This patch fixes this issue by assigning "v" with "-ENOENT" in the
initialization.
back-end device sdm has already attached a cache_set with ID f67ebe1f-f8bc-4d73-bfe5-9dc88607f119, then try to attach with
another cache set, and it returns with an error:
[root]# cd /sys/block/sdm/bcache
[root]# echo 5ccd0a63-148e-48b8-afa2-aca9cbd6279f > attach
-bash: echo: write error: Invalid argument
After that, execute a command to modify the label of bcache
device:
[root]# echo data_disk1 > label
Then we reboot the system, when the system power on, the back-end
device can not attach to cache_set, a messages show in the log:
Feb 5 12:05:52 ceph152 kernel: [922385.508498] bcache:
bch_cached_dev_attach() couldn't find uuid for sdm in set
In sysfs_attach(), dc->sb.set_uuid was assigned to the value
which input through sysfs, no matter whether it is success
or not in bch_cached_dev_attach(). For example, If the back-end
device has already attached to an cache set, bch_cached_dev_attach()
would fail, but dc->sb.set_uuid was changed. Then modify the
label of bcache device, it will call bch_write_bdev_super(),
which would write the dc->sb.set_uuid to the super block, so we
record a wrong cache set ID in the super block, after the system
reboot, the cache set couldn't find the uuid of the back-end
device, so the bcache device couldn't exist and use any more.
In this patch, we don't assigned cache set ID to dc->sb.set_uuid
in sysfs_attach() directly, but input it into bch_cached_dev_attach(),
and assigned dc->sb.set_uuid to the cache set ID after the back-end
device attached to the cache set successful.
After long time running of random small IO writing,
I reboot the machine, and after the machine power on,
I found bcache got stuck, the stack is:
[root@ceph153 ~]# cat /proc/2510/task/*/stack
[<ffffffffa06b2455>] closure_sync+0x25/0x90 [bcache]
[<ffffffffa06b6be8>] bch_journal+0x118/0x2b0 [bcache]
[<ffffffffa06b6dc7>] bch_journal_meta+0x47/0x70 [bcache]
[<ffffffffa06be8f7>] bch_prio_write+0x237/0x340 [bcache]
[<ffffffffa06a8018>] bch_allocator_thread+0x3c8/0x3d0 [bcache]
[<ffffffff810a631f>] kthread+0xcf/0xe0
[<ffffffff8164c318>] ret_from_fork+0x58/0x90
[<ffffffffffffffff>] 0xffffffffffffffff
[root@ceph153 ~]# cat /proc/2038/task/*/stack
[<ffffffffa06b1abd>] __bch_btree_map_nodes+0x12d/0x150 [bcache]
[<ffffffffa06b1bd1>] bch_btree_insert+0xf1/0x170 [bcache]
[<ffffffffa06b637f>] bch_journal_replay+0x13f/0x230 [bcache]
[<ffffffffa06c75fe>] run_cache_set+0x79a/0x7c2 [bcache]
[<ffffffffa06c0cf8>] register_bcache+0xd48/0x1310 [bcache]
[<ffffffff812f702f>] kobj_attr_store+0xf/0x20
[<ffffffff8125b216>] sysfs_write_file+0xc6/0x140
[<ffffffff811dfbfd>] vfs_write+0xbd/0x1e0
[<ffffffff811e069f>] SyS_write+0x7f/0xe0
[<ffffffff8164c3c9>] system_call_fastpath+0x16/0x1
The stack shows the register thread and allocator thread
were getting stuck when registering cache device.
I reboot the machine several times, the issue always
exsit in this machine.
I debug the code, and found the call trace as bellow:
register_bcache()
==>run_cache_set()
==>bch_journal_replay()
==>bch_btree_insert()
==>__bch_btree_map_nodes()
==>btree_insert_fn()
==>btree_split() //node need split
==>btree_check_reserve()
In btree_check_reserve(), It will check if there is enough buckets
of RESERVE_BTREE type, since allocator thread did not work yet, so
no buckets of RESERVE_BTREE type allocated, so the register thread
waits on c->btree_cache_wait, and goes to sleep.
Then the allocator thread initialized, the call trace is bellow:
bch_allocator_thread()
==>bch_prio_write()
==>bch_journal_meta()
==>bch_journal()
==>journal_wait_for_write()
In journal_wait_for_write(), It will check if journal is full by
journal_full(), but the long time random small IO writing
causes the exhaustion of journal buckets(journal.blocks_free=0),
In order to release the journal buckets,
the allocator calls btree_flush_write() to flush keys to
btree nodes, and waits on c->journal.wait until btree nodes writing
over or there has already some journal buckets space, then the
allocator thread goes to sleep. but in btree_flush_write(), since
bch_journal_replay() is not finished, so no btree nodes have journal
(condition "if (btree_current_write(b)->journal)" never satisfied),
so we got no btree node to flush, no journal bucket released,
and allocator sleep all the times.
Through the above analysis, we can see that:
1) Register thread wait for allocator thread to allocate buckets of
RESERVE_BTREE type;
2) Alloctor thread wait for register thread to replay journal, so it
can flush btree nodes and get journal bucket.
then they are all got stuck by waiting for each other.
Hua Rui provided a patch for me, by allocating some buckets of
RESERVE_BTREE type in advance, so the register thread can get bucket
when btree node splitting and no need to waiting for the allocator
thread. I tested it, it has effect, and register thread run a step
forward, but finally are still got stuck, the reason is only 8 bucket
of RESERVE_BTREE type were allocated, and in bch_journal_replay(),
after 2 btree nodes splitting, only 4 bucket of RESERVE_BTREE type left,
then btree_check_reserve() is not satisfied anymore, so it goes to sleep
again, and in the same time, alloctor thread did not flush enough btree
nodes to release a journal bucket, so they all got stuck again.
So we need to allocate more buckets of RESERVE_BTREE type in advance,
but how much is enough? By experience and test, I think it should be
as much as journal buckets. Then I modify the code as this patch,
and test in the machine, and it works.
This patch modified base on Hua Rui’s patch, and allocate more buckets
of RESERVE_BTREE type in advance to avoid register thread and allocate
thread going to wait for each other.
[patch v2] ca->sb.njournal_buckets would be 0 in the first time after
cache creation, and no journal exists, so just 8 btree buckets is OK.
If condition check is true, its task state is set to TASK_INTERRUPTIBLE
and call schedule() to wait for others to wake up it.
There are 2 issues in current code,
1, Task state is set to TASK_INTERRUPTIBLE after the condition checks, if
another process changes the condition and call wake_up_process(dc->
writeback_thread), then at line 452 task state is set back to
TASK_INTERRUPTIBLE, the writeback kernel thread will lose a chance to be
waken up.
2, At line 454 if kthread_should_stop() is true, writeback kernel thread
will return to kernel/kthread.c:kthread() with TASK_INTERRUPTIBLE and
call do_exit(). It is not good to enter do_exit() with task state
TASK_INTERRUPTIBLE, in following code path might_sleep() is called and a
warning message is reported by __might_sleep(): "WARNING: do not call
blocking ops when !TASK_RUNNING; state=1 set at [xxxx]".
For the first issue, task state should be set before condition checks.
Ineed because dc->writeback_lock is required when modifying all the
conditions, calling set_current_state() inside code block where dc->
writeback_lock is hold is safe. But this is quite implicit, so I still move
set_current_state() before all the condition checks.
For the second issue, frankley speaking it does not hurt when kernel thread
exits with TASK_INTERRUPTIBLE state, but this warning message scares users,
makes them feel there might be something risky with bcache and hurt their
data. Setting task state to TASK_RUNNING before returning fixes this
problem.
In alloc.c:allocator_wait(), there is also a similar issue, and is also
fixed in this patch.
Changelog:
v3: merge two similar fixes into one patch
v2: fix the race issue in v1 patch.
v1: initial buggy fix.
Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Michael Lyle <mlyle@lyle.org> Cc: Michael Lyle <mlyle@lyle.org> Cc: Junhui Tang <tang.junhui@zte.com.cn> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This bug was fixed before, but came up again with the latest
compiler in another function:
fs/cifs/cifssmb.c: In function 'CIFSSMBSetEA':
fs/cifs/cifssmb.c:6362:3: error: 'strncpy' offset 8 is out of the bounds [0, 4] [-Werror=array-bounds]
strncpy(parm_data->list[0].name, ea_name, name_len);
Let's apply the same fix that was used for the other instances.
Fixes: b2a3ad9ca502 ("cifs: silence compiler warnings showing up with gcc-4.7.0") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Steve French <smfrench@gmail.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
: This patch breaks criu. It was a bug in criu. And this bug is on a minor
: path, which works when memfd_create() isn't available. It is a reason why
: I ask to not backport this patch to stable kernels.
:
: In CRIU this bug can be triggered, only if this patch will be backported
: to a kernel which version is lower than v3.16.
Link: http://lkml.kernel.org/r/20171120212706.GA14325@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Andrei Vagin <avagin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The page given to gnttab_end_foreign_access() to free could be a
compound page so use put_page() instead of free_page() since it can
handle both compound and single pages correctly.
This bug was discovered when migrating a Xen VM with several VIFs and
CONFIG_DEBUG_VM enabled. It hits a BUG usually after fewer than 10
iterations. All netfront devices disconnect from the backend during a
suspend/resume and this will call gnttab_end_foreign_access() if a
netfront queue has an outstanding skb. The mismatch between calling
get_page() and free_page() on a compound page causes a reference
counting error which is detected when DEBUG_VM is enabled.
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When commit b27311e1cace ("MIPS: TXx9: Add RBTX4939 board support")
added board support for the RBTX4939, it added a call to
led_classdev_register even if the LED class is built as a module.
Built-in arch code cannot call module code directly like this. Commit b33b44073734 ("MIPS: TXX9: use IS_ENABLED() macro") subsequently
changed the inclusion of this code to a single check that
CONFIG_LEDS_CLASS is either builtin or a module, but the same issue
remains.
This leads to MIPS allmodconfig builds failing when CONFIG_MACH_TX49XX=y
is set:
arch/mips/txx9/rbtx4939/setup.o: In function `rbtx4939_led_probe':
setup.c:(.init.text+0xc0): undefined reference to `of_led_classdev_register'
make: *** [Makefile:999: vmlinux] Error 1
This is because if there's only one online CPU, the MSR_PM_ENABLE
(package wide)can not be enabled after resumed, due to
intel_pstate_hwp_enable() will only be invoked on AP's online
process after resumed - if there's no AP online, the HWP remains
disabled after resumed (BIOS has disabled it in S3). Then if
there comes a _PPC change notification which touches HWP register
during this stage, the warning is triggered.
Since we don't call acpi_processor_register_performance() when
HWP is enabled, the pr->performance will be NULL. When this is
NULL we don't need to do _PPC change notification.
The handling of empty DMI strings looks quite broken to me:
* Strings from 1 to 7 spaces are not considered empty.
* True empty DMI strings (string index set to 0) are not considered
empty, and result in allocating a 0-char string.
* Strings with invalid index also result in allocating a 0-char
string.
* Strings starting with 8 spaces are all considered empty, even if
non-space characters follow (sounds like a weird thing to do, but
I have actually seen occurrences of this in DMI tables before.)
* Strings which are considered empty are reported as 8 spaces,
instead of being actually empty.
Some of these issues are the result of an off-by-one error in memcmp,
the rest is incorrect by design.
So let's get it square: missing strings and strings made of only
spaces, regardless of their length, should be treated as empty and
no memory should be allocated for them. All other strings are
non-empty and should be allocated.
Signed-off-by: Jean Delvare <jdelvare@suse.de> Fixes: 79da4721117f ("x86: fix DMI out of memory problems") Cc: Parag Warudkar <parag.warudkar@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The declaration for swsusp_arch_resume marks it as 'asmlinkage', but the
definition in x86-32 does not, and it fails to include the header with the
declaration. This leads to a warning when building with
link-time-optimizations:
kernel/power/power.h:108:23: error: type of 'swsusp_arch_resume' does not match original declaration [-Werror=lto-type-mismatch]
extern asmlinkage int swsusp_arch_resume(void);
^
arch/x86/power/hibernate_32.c:148:0: note: 'swsusp_arch_resume' was previously declared here
int swsusp_arch_resume(void)
This moves the declaration into a globally visible header file and fixes up
both x86 definitions to match it.
Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Len Brown <len.brown@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Nicolas Pitre <nico@linaro.org> Cc: linux-pm@vger.kernel.org Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Pavel Machek <pavel@ucw.cz> Cc: Bart Van Assche <bart.vanassche@wdc.com> Link: https://lkml.kernel.org/r/20180202145634.200291-2-arnd@arndb.de Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On reboot SM can program port pkey table before ipoib registered its
event handler, which could result in missing pkey event and leave root
interface with initial pkey value from index 0.
Since OPA port starts with invalid pkey in index 0, root interface will
fail to initialize and stay down with no-carrier flag.
For IB ipoib interface may end up with pkey different from value
opensm put in pkey table idx 0, resulting in connectivity issues
(different mcast groups, for example).
Close the window by calling event handler after registration
to make sure ipoib pkey is in sync with port pkey table.
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Alex Estrin <alex.estrin@intel.com> Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Minchan Kim asked the following question -- what locks protects
address_space destroying when race happens between inode trauncation and
__isolate_lru_page? Jan Kara clarified by describing the race as follows
CPU1 CPU2
truncate(inode) __isolate_lru_page()
...
truncate_inode_page(mapping, page);
delete_from_page_cache(page)
spin_lock_irqsave(&mapping->tree_lock, flags);
__delete_from_page_cache(page, NULL)
page_cache_tree_delete(..)
... mapping = page_mapping(page);
page->mapping = NULL;
...
spin_unlock_irqrestore(&mapping->tree_lock, flags);
page_cache_free_page(mapping, page)
put_page(page)
if (put_page_testzero(page)) -> false
- inode now has no pages and can be freed including embedded address_space
if (mapping && !mapping->a_ops->migratepage)
- we've dereferenced mapping which is potentially already free.
The race is theoretically possible but unlikely. Before the
delete_from_page_cache, truncate_cleanup_page is called so the page is
likely to be !PageDirty or PageWriteback which gets skipped by the only
caller that checks the mappping in __isolate_lru_page. Even if the race
occurs, a substantial amount of work has to happen during a tiny window
with no preemption but it could potentially be done using a virtual
machine to artifically slow one CPU or halt it during the critical
window.
This patch should eliminate the race with truncation by try-locking the
page before derefencing mapping and aborting if the lock was not
acquired. There was a suggestion from Huang Ying to use RCU as a
side-effect to prevent mapping being freed. However, I do not like the
solution as it's an unconventional means of preserving a mapping and
it's not a context where rcu_read_lock is obviously protecting rcu data.
Link: http://lkml.kernel.org/r/20180104102512.2qos3h5vqzeisrek@techsingularity.net Fixes: c82449352854 ("mm: compaction: make isolate_lru_page() filter-aware again") Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Minchan Kim <minchan@kernel.org> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
projects / thirdparty / kernel / stable.git / log
