Both damn things interpret userland pointers embedded into the payload;
worse, they are actually traversing those. Leaving aside the bad
API design, this is very much _not_ safe to call with KERNEL_DS.
Bail out early if that happens.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
GCC 5 generates different code for this bootwrapper null check that
causes the PS3 to hang very early in its bootup. This check is of
limited value, so just get rid of it.
What matters when deciding if we should make a page uptodate is
not how much we _wanted_ to copy, but how much we actually have
copied. As it is, on architectures that do not zero tail on
short copy we can leave uninitialized data in page marked uptodate.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
After sending an authorizer (ceph_x_authorize_a + ceph_x_authorize_b),
the client gets back a ceph_x_authorize_reply, which it is supposed to
verify to ensure the authenticity and protect against replay attacks.
The code for doing this is there (ceph_x_verify_authorizer_reply(),
ceph_auth_verify_authorizer_reply() + plumbing), but it is never
invoked by the the messenger.
AFAICT this goes back to 2009, when ceph authentication protocols
support was added to the kernel client in 4e7a5dcd1bba ("ceph:
negotiate authentication protocol; implement AUTH_NONE protocol").
The second param of ceph_connection_operations::verify_authorizer_reply
is unused all the way down. Pass 0 to facilitate backporting, and kill
it in the next commit.
The buffer for iucv_message_receive() needs to be below 2 GB. In
__iucv_message_receive(), the buffer address is casted to an u32, which
would result in either memory corruption or an addressing exception when
using addresses >= 2 GB.
Fix this by using GFP_DMA for the buffer allocation.
We previously made sure that the reported disk capacity was less than
0xffffffff blocks when the kernel was not compiled with large sector_t
support (CONFIG_LBDAF). However, this check assumed that the capacity
was reported in units of 512 bytes.
Add a sanity check function to ensure that we only enable disks if the
entire reported capacity can be expressed in terms of sector_t.
Reported-by: Steve Magnani <steve.magnani@digidescorp.com> Cc: Bart Van Assche <Bart.VanAssche@sandisk.com> Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
Kefeng Wang discovered that old versions of the QEMU CD driver would
return mangled mode data causing us to walk off the end of the buffer in
an attempt to parse it. Sanity check the returned mode sense data.
Reported-by: Kefeng Wang <wangkefeng.wang@huawei.com> Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
We see lpfc devices regularly fail during kexec. Fix this by adding a
shutdown method which mirrors the remove method.
Signed-off-by: Anton Blanchard <anton@samba.org> Reviewed-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com> Tested-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
The following fixes a divide by zero OOPs with TYPE_TAPE
due to pscsi_tape_read_blocksize() failing causing a zero
sd->sector_size being propigated up via dev_attrib.hw_block_size.
It also fixes another long-standing bug where TYPE_TAPE and
TYPE_MEDIMUM_CHANGER where using pscsi_create_type_other(),
which does not call scsi_device_get() to take the device
reference. Instead, rename pscsi_create_type_rom() to
pscsi_create_type_nondisk() and use it for all cases.
Finally, also drop a dump_stack() in pscsi_get_blocks() for
non TYPE_DISK, which in modern target-core can get invoked
via target_sense_desc_format() during CHECK_CONDITION.
[js] cast max_sectors to unsigned to avoid warnings
On I/O errors, the Windows driver doesn't set data_transfer_length
on error conditions other than SRB_STATUS_DATA_OVERRUN.
In these cases we need to set data_transfer_length to 0,
indicating there is no data transferred. On SRB_STATUS_DATA_OVERRUN,
data_transfer_length is set by the Windows driver to the actual data transferred.
Reported-by: Shiva Krishna <Shiva.Krishna@nimblestorage.com> Signed-off-by: Long Li <longli@microsoft.com> Reviewed-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
When sense message is present on error, we should pass along to the upper
layer to decide how to deal with the error.
This patch fixes connectivity issues with Fiber Channel devices.
Signed-off-by: Long Li <longli@microsoft.com> Reviewed-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
Don't crash the machine just because of an empty transfer. Use WARN_ON()
combined with returning an error.
Found by Dmitry Vyukov and syzkaller.
[ Changed to "WARN_ON_ONCE()". Al has a patch that should fix the root
cause, but a BUG_ON() is not acceptable in any case, and a WARN_ON()
might still be a cause of excessive log spamming.
NOTE! If this warning ever triggers, we may end up leaking resources,
since this doesn't bother to try to clean the command up. So this
WARN_ON_ONCE() triggering does imply real problems. But BUG_ON() is
much worse.
People really need to stop using BUG_ON() for "this shouldn't ever
happen". It makes pretty much any bug worse. - Linus ]
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: James Bottomley <jejb@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
A race between scanning and fc_remote_port_delete() may result in a
permanent stop if the device gets blocked before scsi_sysfs_add_sdev()
and unblocked after. The reason is that blocking a device sets both the
SDEV_BLOCKED state and the QUEUE_FLAG_STOPPED. However,
scsi_sysfs_add_sdev() unconditionally sets SDEV_RUNNING which causes the
device to be ignored by scsi_target_unblock() and thus never have its
QUEUE_FLAG_STOPPED cleared leading to a device which is apparently
running but has a stopped queue.
We actually have two places where SDEV_RUNNING is set: once in
scsi_add_lun() which respects the blocked flag and once in
scsi_sysfs_add_sdev() which doesn't. Since the second set is entirely
spurious, simply remove it to fix the problem.
Reported-by: Zengxi Chen <chenzengxi@huawei.com> Signed-off-by: Wei Fang <fangwei1@huawei.com> Reviewed-by: Ewan D. Milne <emilne@redhat.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
ast_get_dram_info() configures a window in order to access BMC memory.
A BMC register can be configured to disallow this, and if so, causes
an infinite loop in the ast driver which renders the system unusable.
Fix this by erroring out if an error is detected. On powerpc systems with
EEH, this leads to the device being fenced and the system continuing to
operate.
When there is a CRC error in the SPROM read from the device, the code
attempts to handle a fallback SPROM. When this also fails, the driver
returns zero rather than an error code.
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net> Signed-off-by: Kalle Valo <kvalo@codeaurora.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
If we try to allocate memory pages to back an xfs_buf that we're trying
to read, it's possible that we'll be so short on memory that the page
allocation fails. For a blocking read we'll just wait, but for
readahead we simply dump all the pages we've collected so far.
Unfortunately, after dumping the pages we neglect to clear the
_XBF_PAGES state, which means that the subsequent call to xfs_buf_free
thinks that b_pages still points to pages we own. It then double-frees
the b_pages pages.
This results in screaming about negative page refcounts from the memory
manager, which xfs oughtn't be triggering. To reproduce this case,
mount a filesystem where the size of the inodes far outweighs the
availalble memory (a ~500M inode filesystem on a VM with 300MB memory
did the trick here) and run bulkstat in parallel with other memory
eating processes to put a huge load on the system. The "check summary"
phase of xfs_scrub also works for this purpose.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Cc: Ivan Kozik <ivan@ludios.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Willy Tarreau <w@1wt.eu>
xlog_recover_clear_agi_bucket didn't set the
type to XFS_BLFT_AGI_BUF, so we got a warning during log
replay (or an ASSERT on a debug build).
XFS (md0): Unknown buffer type 0!
XFS (md0): _xfs_buf_ioapply: no ops on block 0xaea8802/0x1
Fix this, as was done in f19b872b for 2 other locations
with the same problem.
Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
The function xen_guest_init is using __alloc_percpu with an alignment
which are not power of two.
However, the percpu allocator never supported alignments which are not power
of two and has always behaved incorectly in thise case.
Commit 3ca45a4 "percpu: ensure requested alignment is power of two"
introduced a check which trigger a warning [1] when booting linux-next
on Xen. But in reality this bug was always present.
This can be fixed by replacing the call to __alloc_percpu with
alloc_percpu. The latter will use an alignment which are a power of two.
The UHCI controllers in Intel chipsets rely on a platform-specific non-PME
mechanism for wakeup signalling. They can generate wakeup signals even
though they don't support PME.
We need to let the USB core know this so that it will enable runtime
suspend for UHCI controllers.
usb_endpoint_maxp() returns wMaxPacketSize in its
raw form. Without taking into consideration that it
also contains other bits reserved for isochronous
endpoints.
This patch fixes one occasion where this is a
problem by making sure that we initialize
ep->maxpacket only with lower 10 bits of the value
returned by usb_endpoint_maxp(). Note that seperate
patches will be necessary to audit all call sites of
usb_endpoint_maxp() and make sure that
usb_endpoint_maxp() only returns lower 10 bits of
wMaxPacketSize.
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
On a system with a defective USB device connected to an USB hub,
an endless sequence of port connect events was observed. The sequence
of events as observed is as follows:
- Port reports connected event (port status=USB_PORT_STAT_CONNECTION).
- Event handler debounces port and resets it by calling hub_port_reset().
- hub_port_reset() calls hub_port_wait_reset() to wait for the reset
to complete.
- The reset completes, but USB_PORT_STAT_CONNECTION is not immediately
set in the port status register.
- hub_port_wait_reset() returns -ENOTCONN.
- Port initialization sequence is aborted.
- A few milliseconds later, the port again reports a connected event,
and the sequence repeats.
This continues either forever or, randomly, stops if the connection
is already re-established when the port status is read. It results in
a high rate of udev events. This in turn destabilizes userspace since
the above sequence holds the device mutex pretty much continuously
and prevents userspace from actually reading the device status.
To prevent the problem from happening, let's wait for the connection
to be re-established after a port reset. If the device was actually
disconnected, the code will still return an error, but it will do so
only after the long reset timeout.
Cc: Douglas Anderson <dianders@chromium.org> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
Upstream commit 98d74f9ceaef ("xhci: fix 10 second timeout on removal of
PCI hotpluggable xhci controllers") fixes a problem with hot pluggable PCI
xhci controllers which can result in excessive timeouts, to the point where
the system reports a deadlock.
The same problem is seen with hot pluggable xhci controllers using the
xhci-plat driver, such as the driver used for Type-C ports on rk3399.
Similar to hot-pluggable PCI controllers, the driver for this chip
removes the xhci controller from the system when the Type-C cable is
disconnected.
The solution for PCI devices works just as well for non-PCI devices
and avoids the problem.
Some gadget drivers are bad, bad boys. We notice
that ADB was passing bad Burst Size which caused top
bits of param0 to be overwritten which confused DWC3
when running this command.
In order to avoid future issues, we're going to make
sure values passed by macros are always safe for the
controller. Note that ADB still needs a fix to *not*
pass bad values.
Reported-by: Mohamed Abbas <mohamed.abbas@intel.com> Sugested-by: Adam Andruszak <adam.andruszak@intel.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
Fix errors during open not being returned to userspace. Specifically,
failed control-line manipulations or control or read urb submissions
would not be detected.
If acm_submit_read_urbs() fails in acm_port_activate(), error handling
code calls usb_autopm_put_interface() while it is already called
before acm_submit_read_urbs(). The patch reorganizes error handling code
to avoid double decrement of USB interface's PM-usage counter.
Found by Linux Driver Verification project (linuxtesting.org).
ep->mult is supposed to be set to Isochronous and
Interrupt Endapoint's multiplier value. This value
is computed from different places depending on the
link speed.
If we're dealing with HighSpeed, then it's part of
bits [12:11] of wMaxPacketSize. This case wasn't
taken into consideration before.
While at that, also make sure the ep->mult defaults
to one so drivers can use it unconditionally and
assume they'll never multiply ep->maxpacket to zero.
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
Bind to the interface, but do not register any ports, after having
downloaded the firmware. The device will still disconnect and
re-enumerate, but this way we avoid an error messages from being logged
as part of the process:
io_ti: probe of 1-1.3:1.0 failed with error -5
Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
Andrey Konovalov's fuzz testing of gadgetfs showed that we should
improve the driver's checks for valid configuration descriptors passed
in by the user. In particular, the driver needs to verify that the
wTotalLength value in the descriptor is not too short (smaller
than USB_DT_CONFIG_SIZE). And the check for whether wTotalLength is
too large has to be changed, because the driver assumes there is
always enough room remaining in the buffer to hold a device descriptor
(at least USB_DT_DEVICE_SIZE bytes).
This patch adds the additional check and fixes the existing check. It
may do a little more than strictly necessary, but one extra check
won't hurt.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
The cause of the bug is subtle. The dev_config() routine gets called
twice by the fuzzer. The first time, the user data contains both a
full-speed configuration descriptor and a high-speed config
descriptor, causing dev->hs_config to be set. But it also contains an
invalid device descriptor, so the buffer containing the descriptors is
deallocated and dev_config() returns an error.
The second time dev_config() is called, the user data contains only a
full-speed config descriptor. But dev->hs_config still has the stale
pointer remaining from the first call, causing the routine to think
that there is a valid high-speed config. Later on, when the driver
dereferences the stale pointer to copy that descriptor, we get a
use-after-free access.
The fix is simple: Clear dev->hs_config if the passed-in data does not
contain a high-speed config descriptor.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-by: Andrey Konovalov <andreyknvl@google.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
Indeed, there is a comment saying that the value of len is restricted
to a 16-bit integer, but the code doesn't actually do this.
This patch fixes the warning. It replaces the comment with a
computation that forces the amount of data copied from the user in
ep0_write() to be no larger than the wLength size for the control
transfer, which is a 16-bit quantity.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-by: Andrey Konovalov <andreyknvl@google.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
Andrey Konovalov reported that we were not properly checking the upper
limit before of a device configuration size before calling
memdup_user(), which could cause some problems.
So set the upper limit to PAGE_SIZE * 4, which should be good enough for
all devices.
The Logitech QuickCam Communicate Deluxe/S7500 microphone fails with the
following warning.
[ 6.778995] usb 2-1.2.2.2: Warning! Unlikely big volume range (=3072),
cval->res is probably wrong.
[ 6.778996] usb 2-1.2.2.2: [5] FU [Mic Capture Volume] ch = 1, val =
4608/7680/1
Adding it to the list of devices in volume_control_quirks makes it work
properly, fixing related typo.
The snd_use_lock_sync() (thus its implementation
snd_use_lock_sync_helper()) has the 5 seconds timeout to break out of
the sync loop. It was introduced from the beginning, just to be
"safer", in terms of avoiding the stupid bugs.
However, as Ben Hutchings suggested, this timeout rather introduces a
potential leak or use-after-free that was apparently fixed by the
commit 2d7d54002e39 ("ALSA: seq: Fix race during FIFO resize"):
for example, snd_seq_fifo_event_in() -> snd_seq_event_dup() ->
copy_from_user() could block for a long time, and snd_use_lock_sync()
goes timeout and still leaves the cell at releasing the pool.
For fixing such a problem, we remove the break by the timeout while
still keeping the warning.
When a new event is queued while processing to resize the FIFO in
snd_seq_fifo_clear(), it may lead to a use-after-free, as the old pool
that is being queued gets removed. For avoiding this race, we need to
close the pool to be deleted and sync its usage before actually
deleting it.
When snd_seq_pool_done() is called, it marks the closing flag to
refuse the further cell insertions. But snd_seq_pool_done() itself
doesn't clear the cells but just waits until all cells are cleared by
the caller side. That is, it's racy, and this leads to the endless
stall as syzkaller spotted.
This patch addresses the racy by splitting the setup of pool->closing
flag out of snd_seq_pool_done(), and calling it properly before
snd_seq_pool_done().
The sequencer FIFO management has a bug that may lead to a corruption
(shortage) of the cell linked list. When a sequencer client faces an
error at the event delivery, it tries to put back the dequeued cell.
When the first queue was put back, this forgot the tail pointer
tracking, and the link will be screwed up.
Although there is no memory corruption, the sequencer client may stall
forever at exit while flushing the pending FIFO cells in
snd_seq_pool_done(), as spotted by syzkaller.
This patch addresses the missing tail pointer tracking at
snd_seq_fifo_cell_putback(). Also the patch makes sure to clear the
cell->enxt pointer at snd_seq_fifo_event_in() for avoiding a similar
mess-up of the FIFO linked list.
When a user sets a too small ticks with a fine-grained timer like
hrtimer, the kernel tries to fire up the timer irq too frequently.
This may lead to the condensed locks, eventually the kernel spinlock
lockup with warnings.
For avoiding such a situation, we define a lower limit of the
resolution, namely 1ms. When the user passes a too small tick value
that results in less than that, the kernel returns -EINVAL now.
snd_seq_pool_done() syncs with closing of all opened threads, but it
aborts the wait loop with a timeout, and proceeds to the release
resource even if not all threads have been closed. The timeout was 5
seconds, and if you run a crazy stuff, it can exceed easily, and may
result in the access of the invalid memory address -- this is what
syzkaller detected in a bug report.
As a fix, let the code graduate from naiveness, simply remove the loop
timeout.
When a sequencer queue is created in snd_seq_queue_alloc(),it adds the
new queue element to the public list before referencing it. Thus the
queue might be deleted before the call of snd_seq_queue_use(), and it
results in the use-after-free error, as spotted by syzkaller.
The fix is to reference the queue object at the right time.
ASUS ROG Ranger VIII with ALC1150 codec requires the extra GPIO pin to
up for the front panel. Just use the existing fixup for setting up
the GPIO pins.
When removing a bcm tx operation either a hrtimer or a tasklet might run.
As the hrtimer triggers its associated tasklet and vice versa we need to
take care to mutually terminate both handlers.
Reported-by: Michael Josenhans <michael.josenhans@web.de> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Tested-by: Michael Josenhans <michael.josenhans@web.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Willy Tarreau <w@1wt.eu>
In order to make the driver work with the common clock framework, this
patch converts the clk_enable()/clk_disable() to
clk_prepare_enable()/clk_disable_unprepare().
The priv->device pointer for c_can_pci is never set, but it is used
without a NULL check in c_can_start(). Setting it in c_can_pci_probe()
like c_can_plat_probe() prevents c_can_pci.ko from crashing, with and
without CONFIG_PM.
This might also cause the pm_runtime_*() functions in c_can.c to
actually be executed for c_can_pci devices - they are the only other
place where priv->device is used, but they all contain a null check.
Signed-off-by: Einar Jón <tolvupostur@gmail.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Willy Tarreau <w@1wt.eu>
This patch adds a check to limit the number of can_filters that can be
set via setsockopt on CAN_RAW sockets. Otherwise allocations > MAX_ORDER
are not prevented resulting in a warning.
Some time ago, chmod command had been executed. As result, the following call
chain left the inode cluster lock in PR state, latter on causing the assert.
system_call_fastpath
-> my_chmod
-> sys_chmod
-> sys_fchmodat
-> notify_change
-> ocfs2_setattr
-> posix_acl_chmod
-> ocfs2_iop_set_acl
-> ocfs2_set_acl
-> ocfs2_acl_set_mode
Here is how.
1119 int ocfs2_setattr(struct dentry *dentry, struct iattr *attr)
1120 {
1247 ocfs2_inode_unlock(inode, 1); <<< WRONG thing to do.
..
1258 if (!status && attr->ia_valid & ATTR_MODE) {
1259 status = posix_acl_chmod(inode, inode->i_mode);
224 int ocfs2_set_acl(handle_t *handle,
225 struct inode *inode, ...
231 {
..
252 ret = ocfs2_acl_set_mode(inode, di_bh,
253 handle, mode);
168 static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head ...
170 {
183 if (handle == NULL) {
>>> BUG: inode lock not held in ex at this point <<<
184 handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
185 OCFS2_INODE_UPDATE_CREDITS);
ocfs2_setattr.#1247 we unlock and at #1259 call posix_acl_chmod. When we reach
ocfs2_acl_set_mode.#181 and do trans, the inode cluster lock is not held in EX
mode (it should be). How this could have happended?
We are the lock master, were holding lock EX and have released it in
ocfs2_setattr.#1247. Note that there are no holders of this lock at
this point. Another node needs the lock in PR, and we downconvert from
EX to PR. So the inode lock is PR when do the trans in
ocfs2_acl_set_mode.#184. The trans stays in core (not flushed to disc).
Now another node want the lock in EX, downconvert thread gets kicked
(the one that tripped assert abovt), finds an unflushed trans but the
lock is not EX (it is PR). If the lock was at EX, it would have flushed
the trans ocfs2_ci_checkpointed -> ocfs2_start_checkpoint before
downconverting (to NULL) for the request.
ocfs2_setattr must not drop inode lock ex in this code path. If it
does, takes it again before the trans, say in ocfs2_set_acl, another
cluster node can get in between, execute another setattr, overwriting
the one in progress on this node, resulting in a mode acl size combo
that is a mix of the two.
Orabug: 20189959 Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Joseph Qi <joseph.qi@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
It's because ocfs2_inode_lock() get us stale LVB in which the i_size is
not equal to the disk i_size. We mistakenly trust the LVB because the
underlaying fsdlm dlm_lock() doesn't set lkb_sbflags with
DLM_SBF_VALNOTVALID properly for us. But, why?
The current code tries to downconvert lock without DLM_LKF_VALBLK flag
to tell o2cb don't update RSB's LVB if it's a PR->NULL conversion, even
if the lock resource type needs LVB. This is not the right way for
fsdlm.
The fsdlm plugin behaves different on DLM_LKF_VALBLK, it depends on
DLM_LKF_VALBLK to decide if we care about the LVB in the LKB. If
DLM_LKF_VALBLK is not set, fsdlm will skip recovering RSB's LVB from
this lkb and set the right DLM_SBF_VALNOTVALID appropriately when node
failure happens.
The following diagram briefly illustrates how this crash happens:
RSB1 is inode metadata lock resource with LOCK_TYPE_USES_LVB;
dlm_lock(no DLM_LKF_VALBLK)
convert_lock(overwrite lkb->lkb_exflags
with no DLM_LKF_VALBLK)
RSB1: NULL RSB1: EX
reset Node2
dlm_recover_rsbs()
recover_lvb()
/* The LVB is not trustable if the node with EX fails and
* no lock >= PR is left. We should set RSB_VALNOTVALID for RSB1.
*/
if(!(kb_exflags & DLM_LKF_VALBLK)) /* This means we miss the chance to
return; * to invalid the LVB here.
*/
The 2nd round:
Node 1 Node2
RSB1(become master from recovery)
ocfs2_setattr()
ocfs2_inode_lock(NULL->EX)
/* dlm_lock() return the stale lvb without setting DLM_SBF_VALNOTVALID */
ocfs2_meta_lvb_is_trustable() return 1 /* so we don't refresh inode from disk */
ocfs2_truncate_file()
mlog_bug_on_msg(disk isize != i_size_read(inode)) /* crash! */
The fix is quite straightforward. We keep to set DLM_LKF_VALBLK flag
for dlm_lock() if the lock resource type needs LVB and the fsdlm plugin
is uesed.
Link: http://lkml.kernel.org/r/1481275846-6604-1-git-send-email-zren@suse.com Signed-off-by: Eric Ren <zren@suse.com> Reviewed-by: Joseph Qi <jiangqi903@gmail.com> Cc: Mark Fasheh <mfasheh@versity.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
commit 4fcd1813e640 ("Fix reconnect to not defer smb3 session reconnect
long after socket reconnect") added support for Negotiate requests to
be initiated by echo calls.
To avoid delays in calling echo after a reconnect, I added the patch
introduced by the commit b8c600120fc8 ("Call echo service immediately
after socket reconnect").
This has however caused a regression with cifs shares which do not have
support for echo calls to trigger Negotiate requests. On connections
which need to call Negotiation, the echo calls trigger an error which
triggers a reconnect which in turn triggers another echo call. This
results in a loop which is only broken when an operation is performed on
the cifs share. For an idle share, it can DOS a server.
The patch uses the smb_operation can_echo() for cifs so that it is
called only if connection has been already been setup.
kernel bz: 194531
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com> Tested-by: Jonathan Liu <net147@gmail.com> Acked-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <smfrench@gmail.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
if, when mounting //HOST/share/sub/dir/foo we can query /sub/dir/foo but
not any of the path components above:
- store the /sub/dir/foo prefix in the cifs super_block info
- in the superblock, set root dentry to the subpath dentry (instead of
the share root)
- set a flag in the superblock to remember it
- use prefixpath when building path from a dentry
fixes bso#8950
Signed-off-by: Aurelien Aptel <aaptel@suse.com> Reviewed-by: Pavel Shilovsky <pshilovsky@samba.org> Signed-off-by: Steve French <smfrench@gmail.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
STATUS_BAD_NETWORK_NAME can be received during node failover,
causing the flag to be set and making the reconnect thread
always unsuccessful, thereafter.
Once the only place where it is set is removed, the remaining
bits are rendered moot.
Removing it does not prevent "mount" from failing when a non
existent share is passed.
What happens when the share really ceases to exist while the
share is mounted is undefined now as much as it was before.
Signed-off-by: Germano Percossi <germano.percossi@citrix.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <smfrench@gmail.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
We can not unlock/lock cifs_tcp_ses_lock while walking through ses
and tcon lists because it can corrupt list iterator pointers and
a tcon structure can be released if we don't hold an extra reference.
Fix it by moving a reconnect process to a separate delayed work
and acquiring a reference to every tcon that needs to be reconnected.
Also do not send an echo request on newly established connections.
Recently I receive a bug report that on Linux v3.0 based kerenl, hot add
disk to a md linear device causes kernel crash at linear_congested(). From
the crash image analysis, I find in linear_congested(), mddev->raid_disks
contains value N, but conf->disks[] only has N-1 pointers available. Then
a NULL pointer deference crashes the kernel.
There is a race between linear_add() and linear_congested(), RCU stuffs
used in these two functions cannot avoid the race. Since Linuv v4.0
RCU code is replaced by introducing mddev_suspend(). After checking the
upstream code, it seems linear_congested() is not called in
generic_make_request() code patch, so mddev_suspend() cannot provent it
from being called. The possible race still exists.
Here I explain how the race still exists in current code. For a machine
has many CPUs, on one CPU, linear_add() is called to add a hard disk to a
md linear device; at the same time on other CPU, linear_congested() is
called to detect whether this md linear device is congested before issuing
an I/O request onto it.
Now I use a possible code execution time sequence to demo how the possible
race happens,
In linear_add() mddev->raid_disks is increased in time seq 2, and on
another CPU in linear_congested() the for-loop iterates conf->disks[i] by
the increased mddev->raid_disks in time seq 3,4. But conf with one more
element (which is a pointer to struct dev_info type) to conf->disks[] is
not updated yet, accessing its structure member in time seq 4 will cause a
NULL pointer deference fault.
To fix this race, there are 2 parts of modification in the patch,
1) Add 'int raid_disks' in struct linear_conf, as a copy of
mddev->raid_disks. It is initialized in linear_conf(), always being
consistent with pointers number of 'struct dev_info disks[]'. When
iterating conf->disks[] in linear_congested(), use conf->raid_disks to
replace mddev->raid_disks in the for-loop, then NULL pointer deference
will not happen again.
2) RCU stuffs are back again, and use kfree_rcu() in linear_add() to
free oldconf memory. Because oldconf may be referenced as mddev->private
in linear_congested(), kfree_rcu() makes sure that its memory will not
be released until no one uses it any more.
Also some code comments are added in this patch, to make this modification
to be easier understandable.
This patch can be applied for kernels since v4.0 after commit: 3be260cc18f8 ("md/linear: remove rcu protections in favour of
suspend/resume"). But this bug is reported on Linux v3.0 based kernel, for
people who maintain kernels before Linux v4.0, they need to do some back
back port to this patch.
Changelog:
- V3: add 'int raid_disks' in struct linear_conf, and use kfree_rcu() to
replace rcu_call() in linear_add().
- v2: add RCU stuffs by suggestion from Shaohua and Neil.
- v1: initial effort.
Signed-off-by: Coly Li <colyli@suse.de> Cc: Shaohua Li <shli@fb.com> Cc: Neil Brown <neilb@suse.com> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
If first_bad == this_sector when we get the WriteMostly disk
in read_balance(), valid disk will be returned with zero
max_sectors. It'll lead to a dead loop in make_request(), and
OOM will happen because of endless allocation of struct bio.
Since we can't get data from this disk in this case, so
continue for another disk.
Signed-off-by: Wei Fang <fangwei1@huawei.com> Signed-off-by: Shaohua Li <shli@fb.com> Cc: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Willy Tarreau <w@1wt.eu>
Current implementation employ 16bit counter of active stripes in lower
bits of bio->bi_phys_segments. If request is big enough to overflow
this counter bio will be completed and freed too early.
Fortunately this not happens in default configuration because several
other limits prevent that: stripe_cache_size * nr_disks effectively
limits count of active stripes. And small max_sectors_kb at lower
disks prevent that during normal read/write operations.
Overflow easily happens in discard if it's enabled by module parameter
"devices_handle_discard_safely" and stripe_cache_size is set big enough.
This patch limits requests size with 256Mb - 8Kb to prevent overflows.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Shaohua Li <shli@kernel.org> Cc: Neil Brown <neilb@suse.com> Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
In dm_sm_metadata_create() we temporarily change the dm_space_map
operations from 'ops' (whose .destroy function deallocates the
sm_metadata) to 'bootstrap_ops' (whose .destroy function doesn't).
If dm_sm_metadata_create() fails in sm_ll_new_metadata() or
sm_ll_extend(), it exits back to dm_tm_create_internal(), which calls
dm_sm_destroy() with the intention of freeing the sm_metadata, but it
doesn't (because the dm_space_map operations is still set to
'bootstrap_ops').
Fix this by setting the dm_space_map operations back to 'ops' if
dm_sm_metadata_create() fails when it is set to 'bootstrap_ops'.
[js] no nr_blocks test in 3.12 yet
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Willy Tarreau <w@1wt.eu>
In crypt_set_key(), if a failure occurs while replacing the old key
(e.g. tfm->setkey() fails) the key must not have DM_CRYPT_KEY_VALID flag
set. Otherwise, the crypto layer would have an invalid key that still
has DM_CRYPT_KEY_VALID flag set.
Signed-off-by: Ondrej Kozina <okozina@redhat.com> Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
When tearing down a block device early in its lifetime, userspace may
still be performing discovery actions like blkdev_ioctl() to re-read
partitions.
The nvdimm_revalidate_disk() implementation depends on
disk->driverfs_dev to be valid at entry. However, it is set to NULL in
del_gendisk() and fatally this is happening *before* the disk device is
deleted from userspace view.
There's no reason for del_gendisk() to clear ->driverfs_dev. That
device is the parent of the disk. It is guaranteed to not be freed
until the disk, as a child, drops its ->parent reference.
We could also fix this issue locally in nvdimm_revalidate_disk() by
using disk_to_dev(disk)->parent, but lets fix it globally since
->driverfs_dev follows the lifetime of the parent. Longer term we
should probably just add a @parent parameter to add_disk(), and stop
carrying this pointer in the gendisk.
Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@fb.com> Reported-by: Robert Hu <robert.hu@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
The WRITE_SAME commands are not present in the blk_default_cmd_filter
write_ok list, and thus are failed with -EPERM when the SG_IO ioctl()
is executed without CAP_SYS_RAWIO capability (e.g., unprivileged users).
[ sg_io() -> blk_fill_sghdr_rq() > blk_verify_command() -> -EPERM ]
The problem can be reproduced with the sg_write_same command
# sg_write_same --num 1 --xferlen 512 /dev/sda
#
# capsh --drop=cap_sys_rawio -- -c \
'sg_write_same --num 1 --xferlen 512 /dev/sda'
Write same: pass through os error: Operation not permitted
#
For comparison, the WRITE_VERIFY command does not observe this problem,
since it is in that list:
That case happens to be exercised by QEMU KVM guests with 'scsi-block' devices
(qemu "-device scsi-block" [1], libvirt "<disk type='block' device='lun'>" [2]),
which employs the SG_IO ioctl() and runs as an unprivileged user (libvirt-qemu).
In that scenario, when a filesystem (e.g., ext4) performs its zero-out calls,
which are translated to write-same calls in the guest kernel, and then into
SG_IO ioctls to the host kernel, SCSI I/O errors may be observed in the guest:
get_task_ioprio() accesses the task->io_context without holding the task
lock and thus can race with exit_io_context(), leading to a
use-after-free. The reproducer below hits this within a few seconds on
my 4-core QEMU VM:
int main(int argc, char **argv)
{
pid_t pid, child;
long nproc, i;
We've fixed the race condition problem in calculating ext4 checksum
value in commit b47820edd163 ("ext4: avoid modifying checksum fields
directly during checksum veficationon"). However, by this change,
when calculating the checksum value of inode whose i_extra_size is
less than 4, we couldn't calculate the checksum value in a proper way.
This problem was found and reported by Nix, Thank you.
Reported-by: Nix <nix@esperi.org.uk> Signed-off-by: Daeho Jeong <daeho.jeong@samsung.com> Signed-off-by: Youngjin Gil <youngjin.gil@samsung.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Willy Tarreau <w@1wt.eu>
If the file system requires journal recovery, and the device is
read-ony, return EROFS to the mount system call. This allows xfstests
generic/050 to pass.
If the journal is aborted, the needs_recovery feature flag should not
be removed. Otherwise, it's the journal might not get replayed and
this could lead to more data getting lost.
If filesystem groups are artifically small (using parameter -g to
mkfs.ext4), ext4_mb_normalize_request() can result in a request that is
larger than a block group. Trim the request size to not confuse
allocation code.
Reported-by: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Willy Tarreau <w@1wt.eu>
If the journal has been aborted, we shouldn't mark the underlying
buffer head as dirty, since that will cause the metadata block to get
modified. And if the journal has been aborted, we shouldn't allow
this since it will almost certainly lead to a corrupted file system.
Ralf Spenneberg reported that he hit a kernel crash when mounting a
modified ext4 image. And it turns out that kernel crashed when
calculating fs overhead (ext4_calculate_overhead()), this is because
the image has very large s_first_meta_bg (debug code shows it's 842150400), and ext4 overruns the memory in count_overhead() when
setting bitmap buffer, which is PAGE_SIZE.
The commit "ext4: sanity check the block and cluster size at mount
time" should prevent any problems, but in case the superblock is
modified while the file system is mounted, add an extra safety check
to make sure we won't overrun the allocated buffer.
Fix a large number of problems with how we handle mount options in the
superblock. For one, if the string in the superblock is long enough
that it is not null terminated, we could run off the end of the string
and try to interpret superblocks fields as characters. It's unlikely
this will cause a security problem, but it could result in an invalid
parse. Also, parse_options is destructive to the string, so in some
cases if there is a comma-separated string, it would be modified in
the superblock. (Fortunately it only happens on file systems with a
1k block size.)
So we can read a btree block via readahead or intentional read,
and we can end up with a memory leak when something happens as
follows,
1) readahead starts to read block A but does not wait for read
completion,
2) btree_readpage_end_io_hook finds that block A is corrupted,
and it needs to clear all block A's pages' uptodate bit.
3) meanwhile an intentional read kicks in and checks block A's
pages' uptodate to decide which page needs to be read.
4) when some pages have the uptodate bit during 3)'s check so
3) doesn't count them for eb->io_pages, but they are later
cleared by 2) so we has to readpage on the page, we get
the wrong eb->io_pages which results in a memory leak of
this block.
This fixes the problem by firstly getting all pages's locking and
then checking pages' uptodate bit.
t1(readahead) t2(readahead endio) t3(the following read)
read_extent_buffer_pages end_bio_extent_readpage
for pg in eb: for page 0,1,2 in eb:
if pg is uptodate: btree_readpage_end_io_hook(pg)
num_reads++ if uptodate:
eb->io_pages = num_reads SetPageUptodate(pg) _______________
for pg in eb: for page 3 in eb: read_extent_buffer_pages
if pg is NOT uptodate: btree_readpage_end_io_hook(pg) for pg in eb:
__extent_read_full_page(pg) sanity check reports something wrong if pg is uptodate:
clear_extent_buffer_uptodate(eb) num_reads++
for pg in eb: eb->io_pages = num_reads
ClearPageUptodate(page) _______________
for pg in eb:
if pg is NOT uptodate:
__extent_read_full_page(pg)
So t3's eb->io_pages is not consistent with the number of pages it's reading,
and during endio(), atomic_dec_and_test(&eb->io_pages) will get a negative
number so that we're not able to free the eb.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
The original patch for mainline, 6f8960541b1 (Btrfs: don't delay
inode ref updates during log replay) lists 1d52c78afbb (Btrfs: try
not to ENOSPC on log replay) as the only pre-3.18 dependency, but it
also depends on 67de11769bd (Btrfs: introduce the delayed inode ref
deletion for the single link inode), which was introduced in 3.14
and isn't in 3.12.y.
The -stable commit added the check to btrfs_delayed_update_inode,
which may look similar to btrfs_delayed_delete_inode_ref, but it's
only superficial. The tops of both functions handle typical
delayed node boilerplate. The upshot is that the patch is harmless
since the caller already checks to see if we're doing log recovery,
so we're not breaking anything. It should be reverted because it
makes it appear as if this issue was fixed for users who did
backport 67de11769bd, when it is not.
Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
In the current DCCP implementation an skb for a DCCP_PKT_REQUEST packet
is forcibly freed via __kfree_skb in dccp_rcv_state_process if
dccp_v6_conn_request successfully returns.
However, if IPV6_RECVPKTINFO is set on a socket, the address of the skb
is saved to ireq->pktopts and the ref count for skb is incremented in
dccp_v6_conn_request, so skb is still in use. Nevertheless, it gets freed
in dccp_rcv_state_process.
Fix by calling consume_skb instead of doing goto discard and therefore
calling __kfree_skb.
Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Willy Tarreau <w@1wt.eu>
The lp_setup() code doesn't apply any bounds checking when passing
"lp=none", and only in this case, resulting in an overflow of the
parport_nr[] array. All versions in Git history are affected.
Reported-By: Roee Hay <roee.hay@hcl.com> Cc: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
In commit 19be0eaffa3a ("mm: remove gup_flags FOLL_WRITE games from
__get_user_pages()"), the mm code was changed from unsetting FOLL_WRITE
after a COW was resolved to setting the (newly introduced) FOLL_COW
instead. Simultaneously, the check in gup.c was updated to still allow
writes with FOLL_FORCE set if FOLL_COW had also been set.
However, a similar check in huge_memory.c was forgotten. As a result,
remote memory writes to ro regions of memory backed by transparent huge
pages cause an infinite loop in the kernel (handle_mm_fault sets
FOLL_COW and returns 0 causing a retry, but follow_trans_huge_pmd bails
out immidiately because `(flags & FOLL_WRITE) && !pmd_write(*pmd)` is
true.
While in this state the process is stil SIGKILLable, but little else
works (e.g. no ptrace attach, no other signals). This is easily
reproduced with the following code (assuming thp are set to always):
Fix this by updating follow_trans_huge_pmd in huge_memory.c analogously
to the update in gup.c in the original commit. The same pattern exists
in follow_devmap_pmd. However, we should not be able to reach that
check with FOLL_COW set, so add WARN_ONCE to make sure we notice if we
ever do.
[akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20170106015025.GA38411@juliacomputing.com Signed-off-by: Keno Fischer <keno@juliacomputing.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Greg Thelen <gthelen@google.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Willy Tarreau <w@1wt.eu> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Michal Hocko <mhocko@suse.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>
[bwh: Backported to 3.2:
- Drop change to follow_devmap_pmd()
- pmd_dirty() is not available; check the page flags as in
can_follow_write_pte()
- Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
[mhocko:
This has been forward ported from the 3.2 stable tree.
And fixed to return NULL.] Reviewed-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Willy Tarreau <w@1wt.eu>
If you have a process that has set itself to be non-dumpable, and it
then undergoes exec(2), any CLOEXEC file descriptors it has open are
"exposed" during a race window between the dumpable flags of the process
being reset for exec(2) and CLOEXEC being applied to the file
descriptors. This can be exploited by a process by attempting to access
/proc/<pid>/fd/... during this window, without requiring CAP_SYS_PTRACE.
The race in question is after set_dumpable has been (for get_link,
though the trace is basically the same for readlink):
Which will return 0, during the race window and CLOEXEC file descriptors
will still be open during this window because do_close_on_exec has not
been called yet. As a result, the ordering of these calls should be
reversed to avoid this race window.
This is of particular concern to container runtimes, where joining a
PID namespace with file descriptors referring to the host filesystem
can result in security issues (since PRCTL_SET_DUMPABLE doesn't protect
against access of CLOEXEC file descriptors -- file descriptors which may
reference filesystem objects the container shouldn't have access to).
Cc: dev@opencontainers.org Reported-by: Michael Crosby <crosbymichael@gmail.com> Signed-off-by: Aleksa Sarai <asarai@suse.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
Currently N_HDLC line discipline uses a self-made singly linked list for
data buffers and has n_hdlc.tbuf pointer for buffer retransmitting after
an error.
The commit be10eb7589337e5defbe214dae038a53dd21add8
("tty: n_hdlc add buffer flushing") introduced racy access to n_hdlc.tbuf.
After tx error concurrent flush_tx_queue() and n_hdlc_send_frames() can put
one data buffer to tx_free_buf_list twice. That causes double free in
n_hdlc_release().
Let's use standard kernel linked list and get rid of n_hdlc.tbuf:
in case of tx error put current data buffer after the head of tx_buf_list.
Signed-off-by: Alexander Popov <alex.popov@linux.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
The class of 4 n_hdls buf locks is the same because a single function
n_hdlc_buf_list_init is used to init all the locks. But since
flush_tx_queue takes n_hdlc->tx_buf_list.spinlock and then calls
n_hdlc_buf_put which takes n_hdlc->tx_free_buf_list.spinlock, lockdep
emits a warning:
=============================================
[ INFO: possible recursive locking detected ]
4.3.0-25.g91e30a7-default #1 Not tainted
---------------------------------------------
a.out/1248 is trying to acquire lock:
(&(&list->spinlock)->rlock){......}, at: [<ffffffffa01fd020>] n_hdlc_buf_put+0x20/0x60 [n_hdlc]
but task is already holding lock:
(&(&list->spinlock)->rlock){......}, at: [<ffffffffa01fdc07>] n_hdlc_tty_ioctl+0x127/0x1d0 [n_hdlc]
other info that might help us debug this:
Possible unsafe locking scenario:
No caller currently checks the return value of
kvm_io_bus_unregister_dev(). This is evil, as all callers silently go on
freeing their device. A stale reference will remain in the io_bus,
getting at least used again, when the iobus gets teared down on
kvm_destroy_vm() - leading to use after free errors.
There is nothing the callers could do, except retrying over and over
again.
So let's simply remove the bus altogether, print an error and make
sure no one can access this broken bus again (returning -ENOMEM on any
attempt to access it).
Fixes: e93f8a0f821e ("KVM: convert io_bus to SRCU") Reported-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[wt: no kvm_io_bus_read_cookie in 3.10, slightly different constructs]
We can easily reach the 1000 limit by start VM with a couple
hundred I/O devices (multifunction=on). The hardcode limit
already been adjusted 3 times (6 ~ 200 ~ 300 ~ 1000).
In userspace, we already have maximum file descriptor to
limit ioeventfd count. But kvm_io_bus devices also are used
for pit, pic, ioapic, coalesced_mmio. They couldn't be limited
by maximum file descriptor.
Currently only ioeventfds take too much kvm_io_bus devices,
so just exclude it from counting kvm_io_range limit.
Also fixed one indent issue in kvm_host.h
Signed-off-by: Amos Kong <akong@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
[wt: next patch depends on this one] Signed-off-by: Willy Tarreau <w@1wt.eu>
When releasing the bus, let's clear the bus pointers to mark it out. If
any further device unregister happens on this bus, we know that we're
done if we found the bus being released already.
commit 2dcab5984841 ("sctp: avoid BUG_ON on sctp_wait_for_sndbuf")
attempted to avoid a BUG_ON call when the association being used for a
sendmsg() is blocked waiting for more sndbuf and another thread did a
peeloff operation on such asoc, moving it to another socket.
As Ben Hutchings noticed, then in such case it would return without
locking back the socket and would cause two unlocks in a row.
Further analysis also revealed that it could allow a double free if the
application managed to peeloff the asoc that is created during the
sendmsg call, because then sctp_sendmsg() would try to free the asoc
that was created only for that call.
This patch takes another approach. It will deny the peeloff operation
if there is a thread sleeping on the asoc, so this situation doesn't
exist anymore. This avoids the issues described above and also honors
the syscalls that are already being handled (it can be multiple sendmsg
calls).
Joint work with Xin Long.
Fixes: 2dcab5984841 ("sctp: avoid BUG_ON on sctp_wait_for_sndbuf") Cc: Alexander Popov <alex.popov@linux.com> Cc: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Willy Tarreau <w@1wt.eu>
Alexander Popov reported that an application may trigger a BUG_ON in
sctp_wait_for_sndbuf if the socket tx buffer is full, a thread is
waiting on it to queue more data and meanwhile another thread peels off
the association being used by the first thread.
This patch replaces the BUG_ON call with a proper error handling. It
will return -EPIPE to the original sendmsg call, similarly to what would
have been done if the association wasn't found in the first place.
Acked-by: Alexander Popov <alex.popov@linux.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Willy Tarreau <w@1wt.eu>
when read/write the 64bit data, the correct lock should be hold.
Fixes: 87b6d218f3adb ("tunnel: implement 64 bits statistics") Cc: Stephen Hemminger <stephen@networkplumber.org> Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Li RongQing <roy.qing.li@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Willy Tarreau <w@1wt.eu>
Casting is a high precedence operation but "off" and "i" are in terms of
bytes so we need to have some parenthesis here.
Fixes: fbfa743a9d2a ("ipv6: fix ip6_tnl_parse_tlv_enc_lim()") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Willy Tarreau <w@1wt.eu>
First one is that pskb_may_pull() may reallocate skb->head,
so the 'raw' pointer needs either to be reloaded or not used at all.
Second issue is that NEXTHDR_DEST handling does not validate
that the options are present in skb->data, so we might read
garbage or access non existent memory.
With help from Willem de Bruijn.
Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Willy Tarreau <w@1wt.eu>
The commit 8dfbcc4351a0 ("[media] xc2028: avoid use after free") tried
to address the reported use-after-free by clearing the reference.
However, it's clearing the wrong pointer; it sets NULL to
priv->ctrl.fname, but it's anyway overwritten by the next line
memcpy(&priv->ctrl, p, sizeof(priv->ctrl)).
OTOH, the actual code accessing the freed string is the strcmp() call
with priv->fname:
if (!firmware_name[0] && p->fname &&
priv->fname && strcmp(p->fname, priv->fname))
free_firmware(priv);
where priv->fname points to the previous file name, and this was
already freed by kfree().
For fixing the bug properly, this patch does the following:
- Keep the copy of firmware file name in only priv->fname,
priv->ctrl.fname isn't changed;
- The allocation is done only when the firmware gets loaded;
- The kfree() is called in free_firmware() commonly
If struct xc2028_config is passed without a firmware name,
the following trouble may happen:
[11009.907205] xc2028 5-0061: type set to XCeive xc2028/xc3028 tuner
[11009.907491] ==================================================================
[11009.907750] BUG: KASAN: use-after-free in strcmp+0x96/0xb0 at addr ffff8803bd78ab40
[11009.907992] Read of size 1 by task modprobe/28992
[11009.907994] =============================================================================
[11009.907997] BUG kmalloc-16 (Tainted: G W ): kasan: bad access detected
[11009.907999] -----------------------------------------------------------------------------
[11009.908130] Bytes b4 ffff8803bd78ab30: 01 00 00 00 2a 07 00 00 9d 28 00 00 01 00 00 00 ....*....(......
[11009.908133] Object ffff8803bd78ab40: 01 00 00 00 00 00 00 00 b0 1d c3 6a 00 88 ff ff ...........j....
[11009.908137] CPU: 3 PID: 28992 Comm: modprobe Tainted: G B W 4.5.0-rc1+ #43
[11009.908140] Hardware name: /NUC5i7RYB, BIOS RYBDWi35.86A.0350.2015.0812.1722 08/12/2015
[11009.908142] ffff8803bd78a000ffff8802c273f1b8ffffffff81932007ffff8803c6407a80
[11009.908148] ffff8802c273f1e8ffffffff81556759ffff8803c6407a80ffffea000ef5e280
[11009.908153] ffff8803bd78ab40dffffc0000000000ffff8802c273f210ffffffff8155ccb4
[11009.908158] Call Trace:
[11009.908162] [<ffffffff81932007>] dump_stack+0x4b/0x64
[11009.908165] [<ffffffff81556759>] print_trailer+0xf9/0x150
[11009.908168] [<ffffffff8155ccb4>] object_err+0x34/0x40
[11009.908171] [<ffffffff8155f260>] kasan_report_error+0x230/0x550
[11009.908175] [<ffffffff81237d71>] ? trace_hardirqs_off_caller+0x21/0x290
[11009.908179] [<ffffffff8155e926>] ? kasan_unpoison_shadow+0x36/0x50
[11009.908182] [<ffffffff8155f5c3>] __asan_report_load1_noabort+0x43/0x50
[11009.908185] [<ffffffff8155ea00>] ? __asan_register_globals+0x50/0xa0
[11009.908189] [<ffffffff8194cea6>] ? strcmp+0x96/0xb0
[11009.908192] [<ffffffff8194cea6>] strcmp+0x96/0xb0
[11009.908196] [<ffffffffa13ba4ac>] xc2028_set_config+0x15c/0x630 [tuner_xc2028]
[11009.908200] [<ffffffffa13bac90>] xc2028_attach+0x310/0x8a0 [tuner_xc2028]
[11009.908203] [<ffffffff8155ea78>] ? memset+0x28/0x30
[11009.908206] [<ffffffffa13ba980>] ? xc2028_set_config+0x630/0x630 [tuner_xc2028]
[11009.908211] [<ffffffffa157a59a>] em28xx_attach_xc3028.constprop.7+0x1f9/0x30d [em28xx_dvb]
[11009.908215] [<ffffffffa157aa2a>] ? em28xx_dvb_init.part.3+0x37c/0x5cf4 [em28xx_dvb]
[11009.908219] [<ffffffffa157a3a1>] ? hauppauge_hvr930c_init+0x487/0x487 [em28xx_dvb]
[11009.908222] [<ffffffffa01795ac>] ? lgdt330x_attach+0x1cc/0x370 [lgdt330x]
[11009.908226] [<ffffffffa01793e0>] ? i2c_read_demod_bytes.isra.2+0x210/0x210 [lgdt330x]
[11009.908230] [<ffffffff812e87d0>] ? ref_module.part.15+0x10/0x10
[11009.908233] [<ffffffff812e56e0>] ? module_assert_mutex_or_preempt+0x80/0x80
[11009.908238] [<ffffffffa157af92>] em28xx_dvb_init.part.3+0x8e4/0x5cf4 [em28xx_dvb]
[11009.908242] [<ffffffffa157a6ae>] ? em28xx_attach_xc3028.constprop.7+0x30d/0x30d [em28xx_dvb]
[11009.908245] [<ffffffff8195222d>] ? string+0x14d/0x1f0
[11009.908249] [<ffffffff8195381f>] ? symbol_string+0xff/0x1a0
[11009.908253] [<ffffffff81953720>] ? uuid_string+0x6f0/0x6f0
[11009.908257] [<ffffffff811a775e>] ? __kernel_text_address+0x7e/0xa0
[11009.908260] [<ffffffff8104b02f>] ? print_context_stack+0x7f/0xf0
[11009.908264] [<ffffffff812e9846>] ? __module_address+0xb6/0x360
[11009.908268] [<ffffffff8137fdc9>] ? is_ftrace_trampoline+0x99/0xe0
[11009.908271] [<ffffffff811a775e>] ? __kernel_text_address+0x7e/0xa0
[11009.908275] [<ffffffff81240a70>] ? debug_check_no_locks_freed+0x290/0x290
[11009.908278] [<ffffffff8104a24b>] ? dump_trace+0x11b/0x300
[11009.908282] [<ffffffffa13e8143>] ? em28xx_register_extension+0x23/0x190 [em28xx]
[11009.908285] [<ffffffff81237d71>] ? trace_hardirqs_off_caller+0x21/0x290
[11009.908289] [<ffffffff8123ff56>] ? trace_hardirqs_on_caller+0x16/0x590
[11009.908292] [<ffffffff812404dd>] ? trace_hardirqs_on+0xd/0x10
[11009.908296] [<ffffffffa13e8143>] ? em28xx_register_extension+0x23/0x190 [em28xx]
[11009.908299] [<ffffffff822dcbb0>] ? mutex_trylock+0x400/0x400
[11009.908302] [<ffffffff810021a1>] ? do_one_initcall+0x131/0x300
[11009.908306] [<ffffffff81296dc7>] ? call_rcu_sched+0x17/0x20
[11009.908309] [<ffffffff8159e708>] ? put_object+0x48/0x70
[11009.908314] [<ffffffffa1579f11>] em28xx_dvb_init+0x81/0x8a [em28xx_dvb]
[11009.908317] [<ffffffffa13e81f9>] em28xx_register_extension+0xd9/0x190 [em28xx]
[11009.908320] [<ffffffffa0150000>] ? 0xffffffffa0150000
[11009.908324] [<ffffffffa0150010>] em28xx_dvb_register+0x10/0x1000 [em28xx_dvb]
[11009.908327] [<ffffffff810021b1>] do_one_initcall+0x141/0x300
[11009.908330] [<ffffffff81002070>] ? try_to_run_init_process+0x40/0x40
[11009.908333] [<ffffffff8123ff56>] ? trace_hardirqs_on_caller+0x16/0x590
[11009.908337] [<ffffffff8155e926>] ? kasan_unpoison_shadow+0x36/0x50
[11009.908340] [<ffffffff8155e926>] ? kasan_unpoison_shadow+0x36/0x50
[11009.908343] [<ffffffff8155e926>] ? kasan_unpoison_shadow+0x36/0x50
[11009.908346] [<ffffffff8155ea37>] ? __asan_register_globals+0x87/0xa0
[11009.908350] [<ffffffff8144da7b>] do_init_module+0x1d0/0x5ad
[11009.908353] [<ffffffff812f2626>] load_module+0x6666/0x9ba0
[11009.908356] [<ffffffff812e9c90>] ? symbol_put_addr+0x50/0x50
[11009.908361] [<ffffffffa1580037>] ? em28xx_dvb_init.part.3+0x5989/0x5cf4 [em28xx_dvb]
[11009.908366] [<ffffffff812ebfc0>] ? module_frob_arch_sections+0x20/0x20
[11009.908369] [<ffffffff815bc940>] ? open_exec+0x50/0x50
[11009.908374] [<ffffffff811671bb>] ? ns_capable+0x5b/0xd0
[11009.908377] [<ffffffff812f5e58>] SyS_finit_module+0x108/0x130
[11009.908379] [<ffffffff812f5d50>] ? SyS_init_module+0x1f0/0x1f0
[11009.908383] [<ffffffff81004044>] ? lockdep_sys_exit_thunk+0x12/0x14
[11009.908394] [<ffffffff822e6936>] entry_SYSCALL_64_fastpath+0x16/0x76
[11009.908396] Memory state around the buggy address:
[11009.908398] ffff8803bd78aa00: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[11009.908401] ffff8803bd78aa80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[11009.908403] >ffff8803bd78ab00: fc fc fc fc fc fc fc fc 00 00 fc fc fc fc fc fc
[11009.908405] ^
[11009.908407] ffff8803bd78ab80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[11009.908409] ffff8803bd78ac00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[11009.908411] ==================================================================
In order to avoid it, let's set the cached value of the firmware
name to NULL after freeing it. While here, return an error if
the memory allocation fails.
When we crash from NMI context (e.g. after NMI injection from host when
'sysctl -w kernel.unknown_nmi_panic=1' is set) we hit
kernel BUG at mm/vmalloc.c:1530!
as vfree() is denied. While the issue could be solved with in_nmi() check
instead I opted for skipping vfree on all sorts of crashes to reduce the
amount of work which can cause consequent crashes. We don't really need to
free anything on crash.
Reported-by: Zhang Yanmin <yanmin.zhang@intel.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Willy Tarreau <w@1wt.eu>
projects / thirdparty / kernel / stable.git / log
