When changing a file's acl mask, ext2_set_acl() will first set the group
bits of i_mode to the value of the mask, and only then set the actual
extended attribute representing the new acl.
If the second part fails (due to lack of space, for example) and the file
had no acl attribute to begin with, the system will from now on assume
that the mask permission bits are actual group permission bits, potentially
granting access to the wrong users.
Prevent this by only changing the inode mode after the acl has been set.
[JK: Rebased on top of "ext2: Don't clear SGID when inheriting ACLs"] Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit
set, DIR1 is expected to have SGID bit set (and owning group equal to
the owning group of 'DIR0'). However when 'DIR0' also has some default
ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on
'DIR1' to get cleared if user is not member of the owning group.
Fix the problem by creating __ext2_set_acl() function that does not call
posix_acl_update_mode() and use it when inheriting ACLs. That prevents
SGID bit clearing and the mode has been properly set by
posix_acl_create() anyway.
Fixes: 073931017b49d9458aa351605b43a7e34598caef CC: linux-ext4@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz>
[bwh: Backported to 3.2:
- Keep using CURRENT_TIME_SEC
- Change parameter order of ext2_set_acl() to match upstream
- Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Actually, at the moment this is not an issue, as every in-tree arch does
the same manual checks for VERIFY_READ vs VERIFY_WRITE, relying on the MMU
to tell them apart, but this wasn't the case in the past and may happen
again on some odd arch in the future.
If anyone cares about 3.7 and earlier, this is a security hole (untested)
on real 80386 CPUs.
Signed-off-by: Adam Borowski <kilobyte@angband.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Jörn Engel noticed that the expand_upwards() function might not return
-ENOMEM in case the requested address is (unsigned long)-PAGE_SIZE and
if the architecture didn't defined TASK_SIZE as multiple of PAGE_SIZE.
Affected architectures are arm, frv, m68k, blackfin, h8300 and xtensa
which all define TASK_SIZE as 0xffffffff, but since none of those have
an upwards-growing stack we currently have no actual issue.
Nevertheless let's fix this just in case any of the architectures with
an upward-growing stack (currently parisc, metag and partly ia64) define
TASK_SIZE similar.
Link: http://lkml.kernel.org/r/20170702192452.GA11868@p100.box Fixes: bd726c90b6b8 ("Allow stack to grow up to address space limit") Signed-off-by: Helge Deller <deller@gmx.de> Reported-by: Jörn Engel <joern@purestorage.com> Cc: Hugh Dickins <hughd@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
When UBIFS prepares data structures which will be written to the MTD it
ensues that their lengths are multiple of 8. Since it uses kmalloc() the
padded bytes are left uninitialized and we leak a few bytes of kernel
memory to the MTD.
To make sure that all bytes are initialized, let's switch to kzalloc().
Kzalloc() is fine in this case because the buffers are not huge and in
the IO path the performance bottleneck is anyway the MTD.
Fixes: 1e51764a3c2a ("UBIFS: add new flash file system") Signed-off-by: Richard Weinberger <richard@nod.at> Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Richard Weinberger <richard@nod.at>
[bwh: Backported to 3.2:
- Drop change in ubifs_jnl_xrename()
- Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
UBIFS handles extended attributes just like files, as consequence of
that, they also have inodes.
Therefore UBIFS does all the inode machinery also for xattrs. Since new
inodes have i_nlink of 1, a file or xattr inode will be evicted
if i_nlink goes down to 0 after an unlink. UBIFS assumes this model also
for xattrs, which is not correct.
One can create a file "foo" with xattr "user.test". By reading
"user.test" an inode will be created, and by deleting "user.test" it
will get evicted later. The assumption breaks if the file "foo", which
hosts the xattrs, will be removed. VFS nor UBIFS does not remove each
xattr via ubifs_xattr_remove(), it just removes the host inode from
the TNC and all underlying xattr nodes too and the inode will remain
in the cache and wastes memory.
To solve this problem, remove xattr inodes from the VFS inode cache in
ubifs_xattr_remove() to make sure that they get evicted.
Fixes: 1e51764a3c2ac05a ("UBIFS: add new flash file system") Signed-off-by: Richard Weinberger <richard@nod.at>
[bwh: Backported to 3.2:
- xattr support is optional, so add an #ifdef around the call
- Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The driver checks port->exists twice in i8042_interrupt(), first when
trying to assign temporary "serio" variable, and second time when deciding
whether it should call serio_interrupt(). The value of port->exists may
change between the 2 checks, and we may end up calling serio_interrupt()
with a NULL pointer:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000050
IP: [<ffffffff8150feaf>] _spin_lock_irqsave+0x1f/0x40
PGD 0
Oops: 0002 [#1] SMP
last sysfs file:
CPU 0
Modules linked in:
To avoid the issue let's change the second check to test whether serio is
NULL or not.
Also, let's take i8042_lock in i8042_start() and i8042_stop() instead of
trying to be overly smart and using memory barriers.
Signed-off-by: Chen Hong <chenhong3@huawei.com>
[dtor: take lock in i8042_start()/i8042_stop()] Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
From POWER4 onwards, mfocrf() only places the specified CR field into
the destination GPR, and the rest of it is set to 0. The PowerPC AS
from version 3.0 now requires this behaviour.
The emulation code currently puts the entire CR into the destination GPR.
Fix it.
Fixes: 6888199f7fe5 ("[POWERPC] Emulate more instructions in software") Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The workaround for the CELL timebase bug does not correctly mark cr0 as
being clobbered. This means GCC doesn't know that the asm block changes cr0 and
might leave the result of an unrelated comparison in cr0 across the block, which
we then trash, leading to basically random behaviour.
Fixes: 859deea949c3 ("[POWERPC] Cell timebase bug workaround") Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
[mpe: Tweak change log and flag for stable] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
__list_lru_walk_one() acquires nlru spin lock (nlru->lock) for longer
duration if there are more number of items in the lru list. As per the
current code, it can hold the spin lock for upto maximum UINT_MAX
entries at a time. So if there are more number of items in the lru
list, then "BUG: spinlock lockup suspected" is observed in the below
path:
Fix this lockup by reducing the number of entries to be shrinked from
the lru list to 1024 at once. Also, add cond_resched() before
processing the lru list again.
Link: http://marc.info/?t=149722864900001&r=1&w=2 Link: http://lkml.kernel.org/r/1498707575-2472-1-git-send-email-stummala@codeaurora.org Signed-off-by: Sahitya Tummala <stummala@codeaurora.org> Suggested-by: Jan Kara <jack@suse.cz> Suggested-by: Vladimir Davydov <vdavydov.dev@gmail.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Alexander Polakov <apolyakov@beget.ru> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2: we don't hold the spin-lock for long, but adding
cond_resched() looks like a good idea] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Commit 1be7107fbe18 ("mm: larger stack guard gap, between vmas") has
introduced a regression in some rust and Java environments which are
trying to implement their own stack guard page. They are punching a new
MAP_FIXED mapping inside the existing stack Vma.
This will confuse expand_{downwards,upwards} into thinking that the
stack expansion would in fact get us too close to an existing non-stack
vma which is a correct behavior wrt safety. It is a real regression on
the other hand.
Let's work around the problem by considering PROT_NONE mapping as a part
of the stack. This is a gros hack but overflowing to such a mapping
would trap anyway an we only can hope that usespace knows what it is
doing and handle it propely.
Fixes: 1be7107fbe18 ("mm: larger stack guard gap, between vmas") Link: http://lkml.kernel.org/r/20170705182849.GA18027@dhcp22.suse.cz Signed-off-by: Michal Hocko <mhocko@suse.com> Debugged-by: Vlastimil Babka <vbabka@suse.cz> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Willy Tarreau <w@1wt.eu> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
validate_scan_freqs() retrieves frequencies from attributes
nested in the attribute NL80211_ATTR_SCAN_FREQUENCIES with
nla_get_u32(), which reads 4 bytes from each attribute
without validating the size of data received. Attributes
nested in NL80211_ATTR_SCAN_FREQUENCIES don't have an nla policy.
Validate size of each attribute before parsing to avoid potential buffer
overread.
Fixes: 2a519311926 ("cfg80211/nl80211: scanning (and mac80211 update to use it)") Signed-off-by: Srinivas Dasari <dasaris@qti.qualcomm.com> Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
nla policy checks for only maximum length of the attribute data
when the attribute type is NLA_BINARY. If userspace sends less
data than specified, the wireless drivers may access illegal
memory. When type is NLA_UNSPEC, nla policy check ensures that
userspace sends minimum specified length number of bytes.
Remove type assignment to NLA_BINARY from nla_policy of
NL80211_ATTR_PMKID to make this NLA_UNSPEC and to make sure minimum
WLAN_PMKID_LEN bytes are received from userspace with
NL80211_ATTR_PMKID.
While cleaning up sysfs callback that prints EK we discovered a kernel
memory leak. This commit fixes the issue by zeroing the buffer used for
TPM command/response.
The leak happen when we use either tpm_vtpm_proxy, tpm_ibmvtpm or
xen-tpmfront.
Fixes: 0883743825e3 ("TPM: sysfs functions consolidation") Reported-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> Tested-by: Stefan Berger <stefanb@linux.vnet.ibm.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
[bwh: Backported to 3.2: adjust filename, context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The crash happens in syscall_get_arguments function for
syscalls with zero arguments, that will try to access
first argument (args[0]) in event entry, but it's not
allocated.
Bail out of there are no arguments.
Reported-by: Zorro Lang <zlang@redhat.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The ib_uverbs_create_ah() ind ib_uverbs_modify_qp() calls receive
the port number from user input as part of its attributes and assumes
it is valid. Down on the stack, that parameter is used to access kernel
data structures. If the value is invalid, the kernel accesses memory
it should not. To prevent this, verify the port number before using it.
BUG: KASAN: use-after-free in ib_uverbs_create_ah+0x6d5/0x7b0
Read of size 4 at addr ffff880018d67ab8 by task syz-executor/313
BUG: KASAN: slab-out-of-bounds in modify_qp.isra.4+0x19d0/0x1ef0
Read of size 4 at addr ffff88006c40ec58 by task syz-executor/819
Fixes: 67cdb40ca444 ("[IB] uverbs: Implement more commands") Fixes: 189aba99e70 ("IB/uverbs: Extend modify_qp and support packet pacing") Cc: <security@kernel.org> Cc: Yevgeny Kliteynik <kliteyn@mellanox.com> Cc: Tziporet Koren <tziporet@mellanox.com> Cc: Alex Polak <alexpo@mellanox.com> Signed-off-by: Boris Pismenny <borisp@mellanox.com> Signed-off-by: Leon Romanovsky <leon@kernel.org> Signed-off-by: Doug Ledford <dledford@redhat.com>
[bwh: Backported to 3.2:
- In modify_qp(), command structure is cmd not cmd->base
- In modify_qp(), add release_qp label
- In ib_uverbs_create_ah(), add definition of ib_dev
- Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Previously start_port and end_port were defined in 2 places, cache.c and
device.c and this prevented their use in other modules.
Make these common functions, change the name to reflect the rdma
name space, and update existing users.
Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
[bwh: Backported to 3.2: drop one inapplicable change] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
We have pretty clear evidence that MSIs are getting lost on g4x and
somehow the interrupt logic doesn't seem to recover from that state
even if we try hard to clear the IIR.
Disabling IER around the normal IIR clearing in the irq handler isn't
sufficient to avoid this, so the problem really seems to be further
up the interrupt chain. This should guarantee that there's always
an edge if any IIR bits are set after the interrupt handler is done,
which should normally guarantee that the CPU interrupt is generated.
That approach seems to work perfectly on VLV/CHV, but apparently
not on g4x.
MSI is documented to be broken on 965gm at least. The chipset spec
says MSI is defeatured because interrupts can be delayed or lost,
which fits well with what we're seeing on g4x. Previously we've
already disabled GMBUS interrupts on g4x because somehow GMBUS
manages to raise legacy interrupts even when MSI is enabled.
Since there's such widespread MSI breakahge all over in the pre-gen5
land let's just give up on MSI on these platforms.
Seqno reporting might be negatively affected by this since the legcy
interrupts aren't guaranteed to be ordered with the seqno writes,
whereas MSI interrupts may be? But an occasioanlly missed seqno
seems like a small price to pay for generally working interrupts.
Cc: Diego Viola <diego.viola@gmail.com> Tested-by: Diego Viola <diego.viola@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=101261 Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170626203051.28480-1-ville.syrjala@linux.intel.com Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
(cherry picked from commit e38c2da01f76cca82b59ca612529b81df82a7cc7) Signed-off-by: Jani Nikula <jani.nikula@intel.com>
[bwh: Backported to 3.2:
- Open-code INTEL_GEN()
- Adjust filename, context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Currently, when the link for $DEV is down, this command succeeds but the
address is removed immediately by DAD (1):
ip addr add 1111::12/64 dev $DEV valid_lft 3600 preferred_lft 1800
In the same situation, this will succeed and not remove the address (2):
ip addr add 1111::12/64 dev $DEV
ip addr change 1111::12/64 dev $DEV valid_lft 3600 preferred_lft 1800
The comment in addrconf_dad_begin() when !IF_READY makes it look like
this is the intended behavior, but doesn't explain why:
* If the device is not ready:
* - keep it tentative if it is a permanent address.
* - otherwise, kill it.
We clearly cannot prevent userspace from doing (2), but we can make (1)
work consistently with (2).
addrconf_dad_stop() is only called in two cases: if DAD failed, or to
skip DAD when the link is down. In that second case, the fix is to avoid
deleting the address, like we already do for permanent addresses.
Fixes: 3c21edbd1137 ("[IPV6]: Defer IPv6 device initialization until the link becomes ready.") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The userspace needs to know why is the address being removed so that it can
perhaps obtain a new address.
Without the DADFAILED flag it's impossible to distinguish removal of a
temporary and tentative address due to DAD failure from other reasons (device
removed, manual address removal).
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The enclosure_add_device() function should fail if it can't create the
relevant sysfs links.
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com> Tested-by: Douglas Miller <dougmill@linux.vnet.ibm.com> Acked-by: James Bottomley <jejb@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Currently we saw a lot of "No irq handler" errors during hibernation, which
caused the system hang finally:
ata4.00: qc timeout (cmd 0xec)
ata4.00: failed to IDENTIFY (I/O error, err_mask=0x4)
ata4.00: revalidation failed (errno=-5)
ata4: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
do_IRQ: 31.151 No irq handler for vector
According to above logs, there is an interrupt triggered and it is
dispatched to CPU31 with a vector number 151, but there is no handler for
it, thus this IRQ will not get acked and will cause an IRQ flood which
kills the system. To be more specific, the 31.151 is an interrupt from the
AHCI host controller.
After some investigation, the reason why this issue is triggered is because
the thaw_noirq() function does not restore the MSI/MSI-X settings across
hibernation.
The scenario is illustrated below:
1. Before hibernation, IRQ 34 is the handler for the AHCI device, which
is bound to CPU31.
2. Hibernation starts, the AHCI device is put into low power state.
3. All the nonboot CPUs are put offline, so IRQ 34 has to be migrated to
the last alive one - CPU0.
4. After the snapshot has been created, all the nonboot CPUs are brought
up again; IRQ 34 remains bound to CPU0.
5. AHCI devices are put into D0.
6. The snapshot is written to the disk.
The issue is triggered in step 6. The AHCI interrupt should be delivered
to CPU0, however it is delivered to the original CPU31 instead, which
causes the "No irq handler" issue.
Ying Huang has provided a clue that, in step 3 it is possible that writing
to the register might not take effect as the PCI devices have been
suspended.
In step 3, the IRQ 34 affinity should be modified from CPU31 to CPU0, but
in fact it is not. In __pci_write_msi_msg(), if the device is already in
low power state, the low level MSI message entry will not be updated but
cached. During the device restore process after a normal suspend/resume,
pci_restore_msi_state() writes the cached MSI back to the hardware.
But this is not the case for hibernation. pci_restore_msi_state() is not
currently called in pci_pm_thaw_noirq(), although pci_save_state() has
saved the necessary PCI cached information in pci_pm_freeze_noirq().
Restore the PCI status for the device during hibernation. Otherwise the
status might be lost across hibernation (for example, settings for MSI,
MSI-X, ATS, ACS, IOV, etc.), which might cause problems during hibernation.
Suggested-by: Ying Huang <ying.huang@intel.com> Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com>
[bhelgaas: changelog] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Len Brown <len.brown@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Rui Zhang <rui.zhang@intel.com> Cc: Ying Huang <ying.huang@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit
set, DIR1 is expected to have SGID bit set (and owning group equal to
the owning group of 'DIR0'). However when 'DIR0' also has some default
ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on
'DIR1' to get cleared if user is not member of the owning group.
Fix the problem by moving posix_acl_update_mode() out of
__btrfs_set_acl() into btrfs_set_acl(). That way the function will not be
called when inheriting ACLs which is what we want as it prevents SGID
bit clearing and the mode has been properly set by posix_acl_create()
anyway.
Fixes: 073931017b49d9458aa351605b43a7e34598caef CC: linux-btrfs@vger.kernel.org CC: David Sterba <dsterba@suse.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: David Sterba <dsterba@suse.com>
[bwh: Backported to 3.2: move the call to posix_acl_update_mode() into
btrfs_xattr_acl_set()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The USB core and sysfs will attempt to enumerate certain parameters
which are unsupported by the au0828 - causing inconsistent behavior
and sometimes causing the chip to reset. Avoid making these calls.
This problem manifested as intermittent cases where the au8522 would
be reset on analog video startup, in particular when starting up ALSA
audio streaming in parallel - the sysfs entries created by
snd-usb-audio on streaming startup would result in unsupported control
messages being sent during tuning which would put the chip into an
unknown state.
Fix commit e50c0a8fa60d ("Support the MIPS32 / MIPS64 DSP ASE.") and
send SIGILL rather than SIGBUS whenever an unimplemented BPOSGE32 DSP
ASE instruction has been encountered in `__compute_return_epc_for_insn'
as our Reserved Instruction exception handler would in response to an
attempt to actually execute the instruction. Sending SIGBUS only makes
sense for the unaligned PC case, since moved to `__compute_return_epc'.
Adjust function documentation accordingly, correct formatting and use
`pr_info' rather than `printk' as the other exit path already does.
Fixes: e50c0a8fa60d ("Support the MIPS32 / MIPS64 DSP ASE.") Signed-off-by: Maciej W. Rozycki <macro@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16396/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
[bwh: Backported to 3.2:
- Drop the comment change
- Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
pm_genpd_remove_subdomain() iterates over domain's master_links list and
removes matching element thus it has to use safe version of list
iteration.
Fixes: f721889ff65a ("PM / Domains: Support for generic I/O PM domains (v8)") Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Neither soft poweroff (transition to ACPI power state S5) nor
suspend-to-RAM (transition to state S3) works on the Macbook Pro 11,4 and
11,5.
The problem is related to the [mem 0x7fa00000-0x7fbfffff] space. When we
use that space, e.g., by assigning it to the 00:1c.0 Root Port, the ACPI
Power Management 1 Control Register (PM1_CNT) at [io 0x1804] doesn't work
anymore.
Linux does a soft poweroff (transition to S5) by writing to PM1_CNT. The
theory about why this doesn't work is:
- The write to PM1_CNT causes an SMI
- The BIOS SMI handler depends on something in
[mem 0x7fa00000-0x7fbfffff]
- When Linux assigns [mem 0x7fa00000-0x7fbfffff] to the 00:1c.0 Port, it
covers up whatever the SMI handler uses, so the SMI handler no longer
works correctly
Reserve the [mem 0x7fa00000-0x7fbfffff] space so we don't assign it to
anything.
This is voodoo programming, since we don't know what the real conflict is,
but we've failed to find the root cause.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=103211 Tested-by: thejoe@gmail.com Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Lukas Wunner <lukas@wunner.de> Cc: Chen Yu <yu.c.chen@intel.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The Haswell Power Control Unit has a non-PCI register (CONFIG_TDP_NOMINAL)
where BAR 0 is supposed to be. This is erratum HSE43 in the spec update
referenced below:
The PCIe* Base Specification indicates that Configuration Space Headers
have a base address register at offset 0x10. Due to this erratum, the
Power Control Unit's CONFIG_TDP_NOMINAL CSR (Bus 1; Device 30; Function
3; Offset 0x10) is located where a base register is expected.
Mark the PCU as having non-compliant BARs so we don't try to probe any of
them. There are no other BARs on this device.
The inline asm retry check in the MIPS_ATOMIC_SET operation of the
sysmips system call has been backwards since commit f1e39a4a616c ("MIPS:
Rewrite sysmips(MIPS_ATOMIC_SET, ...) in C with inline assembler")
merged in v2.6.32, resulting in the non R10000_LLSC_WAR case retrying
until the operation was inatomic, before returning the new value that
was probably just written multiple times instead of the old value.
Invert the branch condition to fix that particular issue.
Fixes: f1e39a4a616c ("MIPS: Rewrite sysmips(MIPS_ATOMIC_SET, ...) in C with inline assembler") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16148/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Make sure to drop the reference to the dma device taken by
of_find_device_by_node() on probe errors and on driver unbind.
Fixes: 334ae614772b ("sparc: Kill SBUS DVMA layer.") Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
If bnx2i_map_ep_dbell_regs() then we accidentally return NULL instead of
an error pointer. It results in a NULL dereference in
iscsi_if_ep_connect().
Fixes: cf4e6363859d ("[SCSI] bnx2i: Add bnx2i iSCSI driver.") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Verify that the caller-provided sockaddr structure is large enough to
contain the sa_family field, before accessing it in bind() and connect()
handlers of the AF_IUCV socket. Since neither syscall enforces a minimum
size of the corresponding memory region, very short sockaddrs (zero or
one byte long) result in operating on uninitialized memory while
referencing .sa_family.
Fixes: 52a82e23b9f2 ("af_iucv: Validate socket address length in iucv_sock_bind()") Signed-off-by: Mateusz Jurczyk <mjurczyk@google.com>
[jwi: removed unneeded null-check for addr] Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
For AMD Promontory xHCI host, although you can disable USB 2.0 ports in
BIOS settings, those ports will be enabled anyway after you remove a
device on that port and re-plug it in again. It's a known limitation of
the chip. As a workaround we can clear the PORT_WAKE_BITS.
This will disable wake on connect, disconnect and overcurrent on
AMD Promontory USB2 ports
[checkpatch cleanup and commit message reword -Mathias] Cc: Tsai Nicholas <nicholas.tsai@amd.com> Signed-off-by: Jiahau Chang <Lars_Chang@asmedia.com.tw> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
udf_setsize() called truncate_setsize() with i_data_sem held. Thus
truncate_pagecache() called from truncate_setsize() could lock a page
under i_data_sem which can deadlock as page lock ranks below
i_data_sem - e. g. writeback can hold page lock and try to acquire
i_data_sem to map a block.
Fix the problem by moving truncate_setsize() calls from under
i_data_sem. It is safe for us to change i_size without holding
i_data_sem as all the places that depend on i_size being stable already
hold inode_lock.
Fixes: 7e49b6f2480cb9a9e7322a91592e56a5c85361f5 Signed-off-by: Jan Kara <jack@suse.cz>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
__udf_adinicb_readpage() uses i_size several times. When truncate
changes i_size while the function is running, it can observe several
different values and thus e.g. expose uninitialized parts of page to
userspace. Also use i_size_read() in the function since it does not hold
inode_lock. Since i_size is guaranteed to be small, this cannot really
cause any issues even on 32-bit archs but let's be careful.
Fixes: 9c2fc0de1a6e638fe58c354a463f544f42a90a09 Signed-off-by: Jan Kara <jack@suse.cz>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The function flush_signals clears all pending signals for the process. It
may be used by kernel threads when we need to prepare a kernel thread for
responding to signals. However using this function for an userspaces
processes is incorrect - clearing signals without the program expecting it
can cause misbehavior.
The raid1 and raid5 code uses flush_signals in its request routine because
it wants to prepare for an interruptible wait. This patch drops
flush_signals and uses sigprocmask instead to block all signals (including
SIGKILL) around the schedule() call. The signals are not lost, but the
schedule() call won't respond to them.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Acked-by: NeilBrown <neilb@suse.com> Signed-off-by: Shaohua Li <shli@fb.com>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
PCI_STD_RESOURCE_END is (confusingly) the index of the last valid BAR, not
the *number* of BARs. To iterate through all possible BARs, we need to
include PCI_STD_RESOURCE_END.
Fixes: 9fe373f9997b ("PCI: Increase IBM ipr SAS Crocodile BARs to at least system page size") Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The usbip stack dynamically allocates the transfer_buffer and
setup_packet of each urb that got generated by the tcp to usb stub code.
As these pointers are always used only once we will set them to NULL
after use. This is done likewise to the free_urb code in vudc_dev.c.
This patch fixes double kfree situations where the usbip remote side
added the URB_FREE_BUFFER.
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de> Acked-by: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust filenames] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
- if (attr->inherit && (attr->sample_type & PERF_SAMPLE_GROUP))
+ if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP))
is a clear fail :/
While this changes user visible behaviour; it was previously possible
to create an inherited event with PERF_SAMPLE_READ; this is deemed
acceptible because its results were always incorrect.
Reported-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vince@deater.net> Fixes: 3dab77fb1bf8 ("perf: Rework/fix the whole read vs group stuff") Link: http://lkml.kernel.org/r/20170530094512.dy2nljns2uq7qa3j@hirez.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Fix urb and transfer-buffer leaks in an urb-submission error path which
may be hit when a device is disconnected.
Fixes: 66e89522aff7 ("V4L/DVB: IR: add mceusb IR receiver driver") Cc: Jarod Wilson <jarod@redhat.com> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Sean Young <sean@mess.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
[bwh: Backported to 3.2:
- Add check on urb_type, as async_buf and async_urb aren't always allocated
- Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
In the stable linux-3.16 branch, I ran into a warning in the
wlcore driver:
drivers/net/wireless/ti/wlcore/spi.c: In function 'wl12xx_spi_raw_write':
drivers/net/wireless/ti/wlcore/spi.c:315:1: error: the frame size of 12848 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]
Newer kernels no longer show the warning, but the bug is still there,
as the allocation is based on the CPU page size rather than the
actual capabilities of the hardware.
This replaces the PAGE_SIZE macro with the SZ_4K macro, i.e. 4096 bytes
per buffer.
Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
[bwh: Backported to 3.2:
- Open-code SZ_4K as it is only defined on some architectures here(!)
- Adjust filename, context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
If we fail to add an interface in mwifiex_add_virtual_intf(), we might
hit a BUG_ON() in the networking code, because we didn't tear things
down properly. Among the problems:
(a) when failing to allocate workqueues, we fail to unregister the
netdev before calling free_netdev()
(b) even if we do try to unregister the netdev, we're still holding the
rtnl lock, so the device never properly unregistered; we'll be at
state NETREG_UNREGISTERING, and then hit free_netdev()'s:
BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
(c) we're allocating some dependent resources (e.g., DFS workqueues)
after we've registered the interface; this may or may not cause
problems, but it's good practice to allocate these before registering
(d) we're not even trying to unwind anything when mwifiex_send_cmd() or
mwifiex_sta_init_cmd() fail
To fix these issues, let's:
* add a stacked set of error handling labels, to keep error handling
consistent and properly ordered (resolving (a) and (d))
* move the workqueue allocations before the registration (to resolve
(c); also resolves (b) by avoiding error cases where we have to
unregister)
[Incidentally, it's pretty easy to interrupt the alloc_workqueue() in,
e.g., the following:
iw phy phy0 interface add mlan0 type station
by sending it SIGTERM.]
This bugfix covers commits like commit 7d652034d1a0 ("mwifiex: channel
switch support for mwifiex"), but parts of this bug exist all the way
back to the introduction of dynamic interface handling in commit 93a1df48d224 ("mwifiex: add cfg80211 handlers add/del_virtual_intf").
Signed-off-by: Brian Norris <briannorris@chromium.org> Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
[bwh: Backported to 3.2:
- There is no workqueue allocation or cleanup needed here
- Add 'ret' variable
- Keep logging errors with wiphy_err()
- Adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
More users for for_each_cpu_wrap() have appeared. Promote the construct
to generic cpumask interface.
The implementation is slightly modified to reduce arguments.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Lauro Ramos Venancio <lvenanci@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: lwang@redhat.com Link: http://lkml.kernel.org/r/20170414122005.o35me2h5nowqkxbv@hirez.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.2: there's no old version of the function to delete] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The 88m1101 has an errata when configuring autoneg. However, it was
being applied to many other Marvell PHYs as well. Limit its scope to
just the 88m1101.
Fixes: 76884679c644 ("phylib: Add support for Marvell 88e1111S and 88e1145") Reported-by: Daniel Walker <danielwa@cisco.com> Signed-off-by: Andrew Lunn <andrew@lunn.ch> Acked-by: Harini Katakam <harinik@xilinx.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The 'move_paghes()' system call was introduced long long ago with the
same permission checks as for sending a signal (except using
CAP_SYS_NICE instead of CAP_SYS_KILL for the overriding capability).
That turns out to not be a great choice - while the system call really
only moves physical page allocations around (and you need other
capabilities to do a lot of it), you can check the return value to map
out some the virtual address choices and defeat ASLR of a binary that
still shares your uid.
So change the access checks to the more common 'ptrace_may_access()'
model instead.
This tightens the access checks for the uid, and also effectively
changes the CAP_SYS_NICE check to CAP_SYS_PTRACE, but it's unlikely that
anybody really _uses_ this legacy system call any more (we hav ebetter
NUMA placement models these days), so I expect nobody to notice.
Famous last words.
Reported-by: Otto Ebeling <otto.ebeling@iki.fi> Acked-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Commit 3268c63 ("mm: fix move/migrate_pages() race on task struct") has
added an odd construct where 'mm' is checked for being NULL, and if it is,
it would get dereferenced anyways by mput()ing it.
Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Commit 3268c63 ("mm: fix move/migrate_pages() race on task struct") has
added an odd construct where 'mm' is checked for being NULL, and if it is,
it would get dereferenced anyways by mput()ing it.
This would lead to the following NULL ptr deref and BUG() when calling
migrate_pages() with a pid that has no mm struct:
Migration functions perform the rcu_read_unlock too early. As a result
the task pointed to may change from under us. This can result in an oops,
as reported by Dave Hansen in https://lkml.org/lkml/2012/2/23/302.
The following patch extend the period of the rcu_read_lock until after the
permissions checks are done. We also take a refcount so that the task
reference is stable when calling security check functions and performing
cpuset node validation (which takes a mutex).
The refcount is dropped before actual page migration occurs so there is no
change to the refcounts held during page migration.
Also move the determination of the mm of the task struct to immediately
before the do_migrate*() calls so that it is clear that we switch from
handling the task during permission checks to the mm for the actual
migration. Since the determination is only done once and we then no
longer use the task_struct we can be sure that we operate on a specific
address space that will not change from under us.
[akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Christoph Lameter <cl@linux.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Reported-by: Dave Hansen <dave@linux.vnet.ibm.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
By checking the effective credentials instead of the real UID / permitted
capabilities, ensure that the calling process actually intended to use its
credentials.
To ensure that all ptrace checks use the correct caller credentials (e.g.
in case out-of-tree code or newly added code omits the PTRACE_MODE_*CREDS
flag), use two new flags and require one of them to be set.
The problem was that when a privileged task had temporarily dropped its
privileges, e.g. by calling setreuid(0, user_uid), with the intent to
perform following syscalls with the credentials of a user, it still passed
ptrace access checks that the user would not be able to pass.
While an attacker should not be able to convince the privileged task to
perform a ptrace() syscall, this is a problem because the ptrace access
check is reused for things in procfs.
In particular, the following somewhat interesting procfs entries only rely
on ptrace access checks:
/proc/$pid/stat - uses the check for determining whether pointers
should be visible, useful for bypassing ASLR
/proc/$pid/maps - also useful for bypassing ASLR
/proc/$pid/cwd - useful for gaining access to restricted
directories that contain files with lax permissions, e.g. in
this scenario:
lrwxrwxrwx root root /proc/13020/cwd -> /root/foobar
drwx------ root root /root
drwxr-xr-x root root /root/foobar
-rw-r--r-- root root /root/foobar/secret
Therefore, on a system where a root-owned mode 6755 binary changes its
effective credentials as described and then dumps a user-specified file,
this could be used by an attacker to reveal the memory layout of root's
processes or reveal the contents of files he is not allowed to access
(through /proc/$pid/cwd).
[akpm@linux-foundation.org: fix warning] Signed-off-by: Jann Horn <jann@thejh.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: Casey Schaufler <casey@schaufler-ca.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Morris <james.l.morris@oracle.com> Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2:
- Drop changes to kcmp, procfs map_files, procfs has_pid_permissions()
- Keep using uid_t, gid_t and == operator for IDs
- Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The current test for bio vec merging is not fully accurate and can be
tricked into merging bios when certain grant combinations are used.
The result of these malicious bio merges is a bio that extends past
the memory page used by any of the originating bios.
Take into account the following scenario, where a guest creates two
grant references that point to the same mfn, ie: grant 1 -> mfn A,
grant 2 -> mfn A.
These references are then used in a PV block request, and mapped by
the backend domain, thus obtaining two different pfns that point to
the same mfn, pfn B -> mfn A, pfn C -> mfn A.
If those grants happen to be used in two consecutive sectors of a disk
IO operation becoming two different bios in the backend domain, the
checks in xen_biovec_phys_mergeable will succeed, because bfn1 == bfn2
(they both point to the same mfn). However due to the bio merging,
the backend domain will end up with a bio that expands past mfn A into
mfn A + 1.
Fix this by making sure the check in xen_biovec_phys_mergeable takes
into account the offset and the length of the bio, this basically
replicates whats done in __BIOVEC_PHYS_MERGEABLE using mfns (bus
addresses). While there also remove the usage of
__BIOVEC_PHYS_MERGEABLE, since that's already checked by the callers
of xen_biovec_phys_mergeable.
Reported-by: "Jan H. Schönherr" <jschoenh@amazon.de> Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[bwh: Backported to 3.2:
- s/bfn/mfn/g
- Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The 'dir' parameter in xfrm_migrate() is a user-controlled byte which is used
as an array index. This can lead to an out-of-bound access, kernel lockup and
DoS. Add a check for the 'dir' value.
This fixes CVE-2017-11600.
References: https://bugzilla.redhat.com/show_bug.cgi?id=1474928 Fixes: 80c9abaabf42 ("[XFRM]: Extension for dynamic update of endpoint address(es)") Reported-by: "bo Zhang" <zhangbo5891001@gmail.com> Signed-off-by: Vladis Dronov <vdronov@redhat.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
When tcp_disconnect() is called, inet_csk_delack_init() sets
icsk->icsk_ack.rcv_mss to 0.
This could potentially cause tcp_recvmsg() => tcp_cleanup_rbuf() =>
__tcp_select_window() call path to have division by 0 issue.
So this patch initializes rcv_mss to TCP_MIN_MSS instead of 0.
Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Wei Wang <weiwan@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Always try to parse an address, since kstrtoul() will safely fail when
given a symbol as input. If that fails (which will be the case for a
symbol), try to parse a symbol instead.
This allows creating a probe such as:
p:probe/vlan_gro_receive 8021q:vlan_gro_receive+0
Which is necessary for this command to work:
perf probe -m 8021q -a vlan_gro_receive
Link: http://lkml.kernel.org/r/fd72d666f45b114e2c5b9cf7e27b91de1ec966f1.1498122881.git.sd@queasysnail.net Fixes: 413d37d1e ("tracing: Add kprobe-based event tracer") Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
[bwh: Backported to 3.2: preserve the check that an addresses isn't used for
a kretprobe] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
When the scheduler sets TIF_NEED_RESCHED & we call into the scheduler
from arch/mips/kernel/entry.S we disable interrupts. This is true
regardless of whether we reach work_resched from syscall_exit_work,
resume_userspace or by looping after calling schedule(). Although we
disable interrupts in these paths we don't call trace_hardirqs_off()
before calling into C code which may acquire locks, and we therefore
leave lockdep with an inconsistent view of whether interrupts are
disabled or not when CONFIG_PROVE_LOCKING & CONFIG_DEBUG_LOCKDEP are
both enabled.
Without tracing this interrupt state lockdep will print warnings such
as the following once a task returns from a syscall via
syscall_exit_partial with TIF_NEED_RESCHED set:
Fix this by using the TRACE_IRQS_OFF macro to call trace_hardirqs_off()
when CONFIG_TRACE_IRQFLAGS is enabled. This is done before invoking
schedule() following the work_resched label because:
1) Interrupts are disabled regardless of the path we take to reach
work_resched() & schedule().
2) Performing the tracing here avoids the need to do it in paths which
disable interrupts but don't call out to C code before hitting a
path which uses the RESTORE_SOME macro that will call
trace_hardirqs_on() or trace_hardirqs_off() as appropriate.
We call trace_hardirqs_on() using the TRACE_IRQS_ON macro before calling
syscall_trace_leave() for similar reasons, ensuring that lockdep has a
consistent view of state after we re-enable interrupts.
Signed-off-by: Paul Burton <paul.burton@imgtec.com> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15385/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Similar to the fix provided by Dominik Heidler in commit 9b3dc0a17d73 ("l2tp: cast l2tp traffic counter to unsigned")
we need to take care of 32bit kernels in dev_get_stats().
When using atomic_long_read(), we add a 'long' to u64 and
might misinterpret high order bit, unless we cast to unsigned.
Fixes: caf586e5f23ce ("net: add a core netdev->rx_dropped counter") Fixes: 015f0688f57ca ("net: net: add a core netdev->tx_dropped counter") Fixes: 6e7333d315a76 ("net: add rx_nohandler stat counter") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jarod Wilson <jarod@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: only rx_dropped is updated here] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
When using get_options() it's possible to specify a range of numbers,
like 1-100500. The problem is that it doesn't track array size while
calling internally to get_range() which iterates over the range and
fills the memory with numbers.
Link: http://lkml.kernel.org/r/2613C75C-B04D-4BFF-82A6-12F97BA0F620@gmail.com Signed-off-by: Ilya V. Matveychikov <matvejchikov@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Emergency stacks have their thread_info mostly uninitialised, which in
particular means garbage preempt_count values.
Emergency stack code runs with interrupts disabled entirely, and is
used very rarely, so this has been unnoticed so far. It was found by a
proposed new powerpc watchdog that takes a soft-NMI directly from the
masked_interrupt handler and using the emergency stack. That crashed
at BUG_ON(in_nmi()) in nmi_enter(). preempt_count()s were found to be
garbage.
To fix this, zero the entire THREAD_SIZE allocation, and initialize
the thread_info.
Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Move it all into setup_64.c, use a function not a macro. Fix
crashes on Cell by setting preempt_count to 0 not HARDIRQ_OFFSET] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
[bwh: Backported to 3.2:
- There's only one emergency stack
- No need to call klp_init_thread_info()
- Add the ti variable in emergency_stack_init()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The per netns loopback_dev->ip6_ptr is unregistered and set to
NULL when its mtu is set to smaller than IPV6_MIN_MTU, this
leads to that we could set rt->rt6i_idev NULL after a
rt6_uncached_list_flush_dev() and then crash after another
call.
In this case we should just bring its inet6_dev down, rather
than unregistering it, at least prior to commit 176c39af29bc
("netns: fix addrconf_ifdown kernel panic") we always
override the case for loopback.
Thanks a lot to Andrey for finding a reliable reproducer.
Fixes: 176c39af29bc ("netns: fix addrconf_ifdown kernel panic") Reported-by: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Daniel Lezcano <dlezcano@fr.ibm.com> Cc: David Ahern <dsahern@gmail.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: David Ahern <dsahern@gmail.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: the NETDEV_CHANGEMTU case used to fall-through to the
NETDEV_DOWN case here, so replace that with a separate call to addrconf_ifdown()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Network interface groups support added while ago, however
there is no IFLA_GROUP attribute description in policy
and netlink message size calculations until now.
Add IFLA_GROUP attribute to the policy.
Fixes: cbda10fa97d7 ("net_device: add support for network device groups") Signed-off-by: Serhey Popovych <serhe.popovych@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Thomas Gleixner wrote:
> The CRIU support added a 'feature' which allows a user space task to send
> arbitrary (kernel) signals to itself. The changelog says:
>
> The kernel prevents sending of siginfo with positive si_code, because
> these codes are reserved for kernel. I think we can allow a task to
> send such a siginfo to itself. This operation should not be dangerous.
>
> Quite contrary to that claim, it turns out that it is outright dangerous
> for signals with info->si_code == SI_TIMER. The following code sequence in
> a user space task allows to crash the kernel:
>
> id = timer_create(CLOCK_XXX, ..... signo = SIGX);
> timer_set(id, ....);
> info->si_signo = SIGX;
> info->si_code = SI_TIMER:
> info->_sifields._timer._tid = id;
> info->_sifields._timer._sys_private = 2;
> rt_[tg]sigqueueinfo(..., SIGX, info);
> sigemptyset(&sigset);
> sigaddset(&sigset, SIGX);
> rt_sigtimedwait(sigset, info);
>
> For timers based on CLOCK_PROCESS_CPUTIME_ID, CLOCK_THREAD_CPUTIME_ID this
> results in a kernel crash because sigwait() dequeues the signal and the
> dequeue code observes:
>
> info->si_code == SI_TIMER && info->_sifields._timer._sys_private != 0
>
> which triggers the following callchain:
>
> do_schedule_next_timer() -> posix_cpu_timer_schedule() -> arm_timer()
>
> arm_timer() executes a list_add() on the timer, which is already armed via
> the timer_set() syscall. That's a double list add which corrupts the posix
> cpu timer list. As a consequence the kernel crashes on the next operation
> touching the posix cpu timer list.
>
> Posix clocks which are internally implemented based on hrtimers are not
> affected by this because hrtimer_start() can handle already armed timers
> nicely, but it's a reliable way to trigger the WARN_ON() in
> hrtimer_forward(), which complains about calling that function on an
> already armed timer.
This problem has existed since the posix timer code was merged into
2.5.63. A few releases earlier in 2.5.60 ptrace gained the ability to
inject not just a signal (which linux has supported since 1.0) but the
full siginfo of a signal.
The core problem is that the code will reschedule in response to
signals getting dequeued not just for signals the timers sent but
for other signals that happen to a si_code of SI_TIMER.
Avoid this confusion by testing to see if the queued signal was
preallocated as all timer signals are preallocated, and so far
only the timer code preallocates signals.
Move the check for if a timer needs to be rescheduled up into
collect_signal where the preallocation check must be performed,
and pass the result back to dequeue_signal where the code reschedules
timers. This makes it clear why the code cares about preallocated
timers.
Reported-by: Thomas Gleixner <tglx@linutronix.de>
History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Reference: 66dd34ad31e5 ("signal: allow to send any siginfo to itself")
Reference: 1669ce53e2ff ("Add PTRACE_GETSIGINFO and PTRACE_SETSIGINFO") Fixes: db8b50ba75f2 ("[PATCH] POSIX clocks & timers") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
This fixes a crash when function_graph and jprobes are used together.
This is essentially commit 237d28db036e ("ftrace/jprobes/x86: Fix
conflict between jprobes and function graph tracing"), but for powerpc.
Jprobes breaks function_graph tracing since the jprobe hook needs to use
jprobe_return(), which never returns back to the hook, but instead to
the original jprobe'd function. The solution is to momentarily pause
function_graph tracing before invoking the jprobe hook and re-enable it
when returning back to the original jprobe'd function.
Fixes: 6794c78243bf ("powerpc64: port of the function graph tracer") Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
[bwh: Backported to 3.2: include <linux/ftrace.h>, which apparently gets
included indirectly upstream] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The default error code in pfkey_msg2xfrm_state() is -ENOBUFS. We
added a new call to security_xfrm_state_alloc() which sets "err" to zero
so there several places where we can return ERR_PTR(0) if kmalloc()
fails. The caller is expecting error pointers so it leads to a NULL
dereference.
Fixes: df71837d5024 ("[LSM-IPSec]: Security association restriction.") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The double free problem involves the mnt_opts field of the
security_mnt_opts struct, selinux_parse_opts_str() frees the memory
on error, but doesn't set the field to NULL so if the caller later
attempts to call security_free_mnt_opts() we trigger the problem.
In order to play it safe we change selinux_parse_opts_str() to call
security_free_mnt_opts() on error instead of free'ing the memory
directly. This should ensure that everything is handled correctly,
regardless of what the caller may do.
Fixes: e0007529893c1c06 ("LSM/SELinux: Interfaces to allow FS to control mount options") Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
When plugging an USB webcam I see the following message:
[106385.615559] xhci_hcd 0000:04:00.0: WARN Successful completion on short TX: needs XHCI_TRUST_TX_LENGTH quirk?
[106390.583860] handle_tx_event: 913 callbacks suppressed
With this patch applied, I get no more printing of this message.
This patch closes a long standing race in configfs between
the creation of a new symlink in create_link(), while the
symlink target's config_item is being concurrently removed
via configfs_rmdir().
This can happen because the symlink target's reference
is obtained by config_item_get() in create_link() before
the CONFIGFS_USET_DROPPING bit set by configfs_detach_prep()
during configfs_rmdir() shutdown is actually checked..
This originally manifested itself on ppc64 on v4.8.y under
heavy load using ibmvscsi target ports with Novalink API:
To close this race, go ahead and obtain the symlink's target
config_item reference only after the existing CONFIGFS_USET_DROPPING
check succeeds.
This way, if configfs_rmdir() wins create_link() will return -ENONET,
and if create_link() wins configfs_rmdir() will return -EBUSY.
Reported-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com> Tested-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
INFO: task gnome-terminal-:1734 blocked for more than 120 seconds.
Not tainted 4.12.0-rc4+ #8
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
gnome-terminal- D 0 1734 1015 0x00000000
Call Trace:
__schedule+0x3cd/0xb30
schedule+0x40/0x90
kvm_async_pf_task_wait+0x1cc/0x270
? __vfs_read+0x37/0x150
? prepare_to_swait+0x22/0x70
do_async_page_fault+0x77/0xb0
? do_async_page_fault+0x77/0xb0
async_page_fault+0x28/0x30
This is triggered by running both win7 and win2016 on L1 KVM simultaneously,
and then gives stress to memory on L1, I can observed this hang on L1 when
at least ~70% swap area is occupied on L0.
This is due to async pf was injected to L2 which should be injected to L1,
L2 guest starts receiving pagefault w/ bogus %cr2(apf token from the host
actually), and L1 guest starts accumulating tasks stuck in D state in
kvm_async_pf_task_wait() since missing PAGE_READY async_pfs.
This patch fixes the hang by doing async pf when executing L1 guest.
Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
As it is, short copy in write() to append-only file will fail
to truncate the excessive allocated blocks. As the matter of
fact, all checks in ufs_truncate_blocks() are either redundant
or wrong for that caller. As for the only other caller
(ufs_evict_inode()), we only need the file type checks there.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.2:
- No functions need to be renamed
- Adjust filenames, context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
sys_add_key() and the KEYCTL_UPDATE operation of sys_keyctl() allowed a
NULL payload with nonzero length to be passed to the key type's
->preparse(), ->instantiate(), and/or ->update() methods. Various key
types including asymmetric, cifs.idmap, cifs.spnego, and pkcs7_test did
not handle this case, allowing an unprivileged user to trivially cause a
NULL pointer dereference (kernel oops) if one of these key types was
present. Fix it by doing the copy_from_user() when 'plen' is nonzero
rather than when '_payload' is non-NULL, causing the syscall to fail
with EFAULT as expected when an invalid buffer is specified.
Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
When ftrace is used with kprobes, it is possible for a kprobe to contain
an invalid location (ie. only initialised to 0 and not to a specific
location in the code). Trying to perform a cache flush on such location
leads to a crash r4k_flush_icache_range().
If "i" is the last element in the vcpu->arch.cpuid_entries[] array, it
potentially can be exploited the vulnerability. this will out-of-bounds
read and write. Luckily, the effect is small:
/* when no next entry is found, the current entry[i] is reselected */
for (j = i + 1; ; j = (j + 1) % nent) {
struct kvm_cpuid_entry2 *ej = &vcpu->arch.cpuid_entries[j];
if (ej->function == e->function) {
It reads ej->maxphyaddr, which is user controlled. However...
ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
After cpuid_entries there is
int maxphyaddr;
struct x86_emulate_ctxt emulate_ctxt; /* 16-byte aligned */
So we have:
- cpuid_entries at offset 1B50 (6992)
- maxphyaddr at offset 27D0 (6992 + 3200 = 10192)
- padding at 27D4...27DF
- emulate_ctxt at 27E0
And it writes in the padding. Pfew, writing the ops field of emulate_ctxt
would have been much worse.
This patch fixes it by modding the index to avoid the out-of-bounds
access. Worst case, i == j and ej->function == e->function,
the loop can bail out.
Reported-by: Moguofang <moguofang@huawei.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Guofang Mo <moguofang@huawei.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[bwh: Backported to 3.2: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Few shell command examples in perf-script-python.txt has few nitpicks
include:
- tools/perf/scripts/python directory listing command is unnecessarily
repeated.
- few examples contain additional information in command prompt
unnecessarily and inconsistently.
This commit fixes them to enhance readability of the document.
Signed-off-by: SeongJae Park <sj38.park@gmail.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tom Zanussi <tzanussi@gmail.com> Fixes: cff68e582237 ("perf/scripts: Add perf-trace-python Documentation") Link: http://lkml.kernel.org/r/20170530111827.21732-4-sj38.park@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Default function signature of trace_unhandled() got changed to include a
field dict, but its documentation, perf-script-python.txt has not been
updated. Fix it.
Signed-off-by: SeongJae Park <sj38.park@gmail.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Pierre Tardy <tardyp@gmail.com> Fixes: c02514850d67 ("perf scripts python: Give field dict to unhandled callback") Link: http://lkml.kernel.org/r/20170530111827.21732-6-sj38.park@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Script generated by the '--gen-script' option contains an outdated
comment. It mentions a 'perf-trace-python' document while it has been
renamed to 'perf-script-python'. Fix it.
Signed-off-by: SeongJae Park <sj38.park@gmail.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 133dc4c39c57 ("perf: Rename 'perf trace' to 'perf script'") Link: http://lkml.kernel.org/r/20170530111827.21732-2-sj38.park@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ethoc_reset enables device interrupts, ethoc_interrupt may schedule a
NAPI poll before NAPI is enabled in the ethoc_open, which results in
device being unable to send or receive anything until it's closed and
reopened. In case the device is flooded with ingress packets it may be
unable to recover at all.
Move napi_enable above ethoc_reset in the ethoc_open to fix that.
Fixes: a1702857724f ("net: Add support for the OpenCores 10/100 Mbps Ethernet MAC.") Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Reviewed-by: Tobias Klauser <tklauser@distanz.ch> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Alexander reported various KASAN messages triggered in recent kernels
The problem is that ping sockets should not use udp_poll() in the first
place, and recent changes in UDP stack finally exposed this old bug.
Fixes: c319b4d76b9e ("net: ipv4: add IPPROTO_ICMP socket kind") Fixes: 6d0bfe226116 ("net: ipv6: Add IPv6 support to the ping socket.") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Sasha Levin <alexander.levin@verizon.com> Cc: Solar Designer <solar@openwall.com> Cc: Vasiliy Kulikov <segoon@openwall.com> Cc: Lorenzo Colitti <lorenzo@google.com> Acked-By: Lorenzo Colitti <lorenzo@google.com> Tested-By: Lorenzo Colitti <lorenzo@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2:
- Drop IPv6 bits
- Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
If ip6_find_1stfragopt() fails and we return an error we have to free
up 'segs' because nobody else is going to.
Fixes: 2423496af35d ("ipv6: Prevent overrun when parsing v6 header options") Reported-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: adjust filename, context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
A rc device can call ir_raw_event_handle() after rc_allocate_device(),
but before rc_register_device() has completed. This is racey because
rcdev->raw is set before rcdev->raw->thread has a valid value.
Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Sean Young <sean@mess.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
[bwh: Backported to 3.2: adjust filename, context, indentation] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The alarmtimer code has another source of potentially rearming itself too
fast. Interval timers with a very samll interval have a similar CPU hog
effect as the previously fixed overflow issue.
The reason is that alarmtimers do not implement the normal protection
against this kind of problem which the other posix timer use:
timer expires -> queue signal -> deliver signal -> rearm timer
This scheme brings the rearming under scheduler control and prevents
permanently firing timers which hog the CPU.
Bringing this scheme to the alarm timer code is a major overhaul because it
lacks all the necessary mechanisms completely.
So for a quick fix limit the interval to one jiffie. This is not
problematic in practice as alarmtimers are usually backed by an RTC for
suspend which have 1 second resolution. It could be therefor argued that
the resolution of this clock should be set to 1 second in general, but
that's outside the scope of this fix.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Kostya Serebryany <kcc@google.com> Cc: syzkaller <syzkaller@googlegroups.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Dmitry Vyukov <dvyukov@google.com> Link: http://lkml.kernel.org/r/20170530211655.896767100@linutronix.de
[bwh: Backported to 3.2:
- Use ktime_to_ns()/ktime_set() as ktime_t is not scalar
- Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Andrey reported a alartimer related RCU stall while fuzzing the kernel with
syzkaller.
The reason for this is an overflow in ktime_add() which brings the
resulting time into negative space and causes immediate expiry of the
timer. The following rearm with a small interval does not bring the timer
back into positive space due to the same issue.
This results in a permanent firing alarmtimer which hogs the CPU.
Use ktime_add_safe() instead which detects the overflow and clamps the
result to KTIME_SEC_MAX.
Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Kostya Serebryany <kcc@google.com> Cc: syzkaller <syzkaller@googlegroups.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Dmitry Vyukov <dvyukov@google.com> Link: http://lkml.kernel.org/r/20170530211655.802921648@linutronix.de
[bwh: Backported to 3.2: drop change in alarm_start_relative()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
projects / thirdparty / kernel / stable.git / log
