| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
iio: proximity: hx9023s: Protect against division by zero in set_samp_freq
Avoid division by zero when sampling frequency is unspecified. |
| In the Linux kernel, the following vulnerability has been resolved:
most: core: fix leak on early registration failure
A recent commit fixed a resource leak on early registration failures but
for some reason left out the first error path which still leaks the
resources associated with the interface.
Fix up also the first error path so that the interface is always
released on errors. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: fix sync handling in amdgpu_dma_buf_move_notify
Invalidating a dmabuf will impact other users of the shared BO.
In the scenario where process A moves the BO, it needs to inform
process B about the move and process B will need to update its
page table.
The commit fixes a synchronisation bug caused by the use of the
ticket: it made amdgpu_vm_handle_moved behave as if updating
the page table immediately was correct but in this case it's not.
An example is the following scenario, with 2 GPUs and glxgears
running on GPU0 and Xorg running on GPU1, on a system where P2P
PCI isn't supported:
glxgears:
export linear buffer from GPU0 and import using GPU1
submit frame rendering to GPU0
submit tiled->linear blit
Xorg:
copy of linear buffer
The sequence of jobs would be:
drm_sched_job_run # GPU0, frame rendering
drm_sched_job_queue # GPU0, blit
drm_sched_job_done # GPU0, frame rendering
drm_sched_job_run # GPU0, blit
move linear buffer for GPU1 access #
amdgpu_dma_buf_move_notify -> update pt # GPU0
It this point the blit job on GPU0 is still running and would
likely produce a page fault. |
| In the Linux kernel, the following vulnerability has been resolved:
spi: spidev: fix lock inversion between spi_lock and buf_lock
The spidev driver previously used two mutexes, spi_lock and buf_lock,
but acquired them in different orders depending on the code path:
write()/read(): buf_lock -> spi_lock
ioctl(): spi_lock -> buf_lock
This AB-BA locking pattern triggers lockdep warnings and can
cause real deadlocks:
WARNING: possible circular locking dependency detected
spidev_ioctl() -> mutex_lock(&spidev->buf_lock)
spidev_sync_write() -> mutex_lock(&spidev->spi_lock)
*** DEADLOCK ***
The issue is reproducible with a simple userspace program that
performs write() and SPI_IOC_WR_MAX_SPEED_HZ ioctl() calls from
separate threads on the same spidev file descriptor.
Fix this by simplifying the locking model and removing the lock
inversion entirely. spidev_sync() no longer performs any locking,
and all callers serialize access using spi_lock.
buf_lock is removed since its functionality is fully covered by
spi_lock, eliminating the possibility of lock ordering issues.
This removes the lock inversion and prevents deadlocks without
changing userspace ABI or behaviour. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix dsc eDP issue
[why]
Need to add function hook check before use |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Properly mark live registers for indirect jumps
For a `gotox rX` instruction the rX register should be marked as used
in the compute_insn_live_regs() function. Fix this. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_sync: Fix UAF in le_read_features_complete
This fixes the following backtrace caused by hci_conn being freed
before le_read_features_complete but after
hci_le_read_remote_features_sync so hci_conn_del -> hci_cmd_sync_dequeue
is not able to prevent it:
==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1383 [inline]
BUG: KASAN: slab-use-after-free in hci_conn_drop include/net/bluetooth/hci_core.h:1688 [inline]
BUG: KASAN: slab-use-after-free in le_read_features_complete+0x5b/0x340 net/bluetooth/hci_sync.c:7344
Write of size 4 at addr ffff8880796b0010 by task kworker/u9:0/52
CPU: 0 UID: 0 PID: 52 Comm: kworker/u9:0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: hci0 hci_cmd_sync_work
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xcd/0x630 mm/kasan/report.c:482
kasan_report+0xe0/0x110 mm/kasan/report.c:595
check_region_inline mm/kasan/generic.c:194 [inline]
kasan_check_range+0x100/0x1b0 mm/kasan/generic.c:200
instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1383 [inline]
hci_conn_drop include/net/bluetooth/hci_core.h:1688 [inline]
le_read_features_complete+0x5b/0x340 net/bluetooth/hci_sync.c:7344
hci_cmd_sync_work+0x1ff/0x430 net/bluetooth/hci_sync.c:334
process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>
Allocated by task 5932:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
poison_kmalloc_redzone mm/kasan/common.c:400 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:417
kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
__hci_conn_add+0xf8/0x1c70 net/bluetooth/hci_conn.c:963
hci_conn_add_unset+0x76/0x100 net/bluetooth/hci_conn.c:1084
le_conn_complete_evt+0x639/0x1f20 net/bluetooth/hci_event.c:5714
hci_le_enh_conn_complete_evt+0x23d/0x380 net/bluetooth/hci_event.c:5861
hci_le_meta_evt+0x357/0x5e0 net/bluetooth/hci_event.c:7408
hci_event_func net/bluetooth/hci_event.c:7716 [inline]
hci_event_packet+0x685/0x11c0 net/bluetooth/hci_event.c:7773
hci_rx_work+0x2c9/0xeb0 net/bluetooth/hci_core.c:4076
process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Freed by task 5932:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
__kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:587
kasan_save_free_info mm/kasan/kasan.h:406 [inline]
poison_slab_object mm/kasan/common.c:252 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284
kasan_slab_free include/linux/kasan.h:234 [inline]
slab_free_hook mm/slub.c:2540 [inline]
slab_free mm/slub.c:6663 [inline]
kfree+0x2f8/0x6e0 mm/slub.c:6871
device_release+0xa4/0x240 drivers/base/core.c:2565
kobject_cleanup lib/kobject.c:689 [inline]
kobject_release lib/kobject.c:720 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x1e7/0x590 lib/kobject.
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
USB: dummy-hcd: Fix interrupt synchronization error
This fixes an error in synchronization in the dummy-hcd driver. The
error has a somewhat involved history. The synchronization mechanism
was introduced by commit 7dbd8f4cabd9 ("USB: dummy-hcd: Fix erroneous
synchronization change"), which added an emulated "interrupts enabled"
flag together with code emulating synchronize_irq() (it waits until
all current handler callbacks have returned).
But the emulated interrupt-disable occurred too late, after the driver
containing the handler callback routines had been told that it was
unbound and no more callbacks would occur. Commit 4a5d797a9f9c ("usb:
gadget: dummy_hcd: fix gpf in gadget_setup") tried to fix this by
moving the synchronize_irq() emulation code from dummy_stop() to
dummy_pullup(), which runs before the unbind callback.
There still were races, though, because the emulated interrupt-disable
still occurred too late. It couldn't be moved to dummy_pullup(),
because that routine can be called for reasons other than an impending
unbind. Therefore commits 7dc0c55e9f30 ("USB: UDC core: Add
udc_async_callbacks gadget op") and 04145a03db9d ("USB: UDC: Implement
udc_async_callbacks in dummy-hcd") added an API allowing the UDC core
to tell dummy-hcd exactly when emulated interrupts and their callbacks
should be disabled.
That brings us to the current state of things, which is still wrong
because the emulated synchronize_irq() occurs before the emulated
interrupt-disable! That's no good, beause it means that more emulated
interrupts can occur after the synchronize_irq() emulation has run,
leading to the possibility that a callback handler may be running when
the gadget driver is unbound.
To fix this, we have to move the synchronize_irq() emulation code yet
again, to the dummy_udc_async_callbacks() routine, which takes care of
enabling and disabling emulated interrupt requests. The
synchronization will now run immediately after emulated interrupts are
disabled, which is where it belongs. |
| In the Linux kernel, the following vulnerability has been resolved:
md raid: fix hang when stopping arrays with metadata through dm-raid
When using device-mapper's dm-raid target, stopping a RAID array can cause
the system to hang under specific conditions.
This occurs when:
- A dm-raid managed device tree is suspended from top to bottom
(the top-level RAID device is suspended first, followed by its
underlying metadata and data devices)
- The top-level RAID device is then removed
Removing the top-level device triggers a hang in the following sequence:
the dm-raid destructor calls md_stop(), which tries to flush the
write-intent bitmap by writing to the metadata sub-devices. However, these
devices are already suspended, making them unable to complete the write-intent
operations and causing an indefinite block.
Fix:
- Prevent bitmap flushing when md_stop() is called from dm-raid
destructor context
and avoid a quiescing/unquescing cycle which could also cause I/O
- Still allow write-intent bitmap flushing when called from dm-raid
suspend context
This ensures that RAID array teardown can complete successfully even when the
underlying devices are in a suspended state.
This second patch uses md_is_rdwr() to distinguish between suspend and
destructor paths as elaborated on above. |
| In the Linux kernel, the following vulnerability has been resolved:
media: verisilicon: Avoid G2 bus error while decoding H.264 and HEVC
For the i.MX8MQ platform, there is a hardware limitation: the g1 VPU and
g2 VPU cannot decode simultaneously; otherwise, it will cause below bus
error and produce corrupted pictures, even potentially lead to system hang.
[ 110.527986] hantro-vpu 38310000.video-codec: frame decode timed out.
[ 110.583517] hantro-vpu 38310000.video-codec: bus error detected.
Therefore, it is necessary to ensure that g1 and g2 operate alternately.
This allows for successful multi-instance decoding of H.264 and HEVC.
To achieve this, g1 and g2 share the same v4l2_m2m_dev, and then the
v4l2_m2m_dev can handle the scheduling. |
| A use-after-free flaw was found in the netfilter subsystem of the Linux kernel. If the catchall element is garbage-collected when the pipapo set is removed, the element can be deactivated twice. This can cause a use-after-free issue on an NFT_CHAIN object or NFT_OBJECT object, allowing a local unprivileged user with CAP_NET_ADMIN capability to escalate their privileges on the system. |
| In the Linux kernel, the following vulnerability has been resolved:
media: i2c: ov5647: Initialize subdev before controls
In ov5647_init_controls() we call v4l2_get_subdevdata, but it is
initialized by v4l2_i2c_subdev_init() in the probe, which currently
happens after init_controls(). This can result in a segfault if the
error condition is hit, and we try to access i2c_client, so fix the
order. |
| In the Linux kernel, the following vulnerability has been resolved:
ACPI: processor: Fix NULL-pointer dereference in acpi_processor_errata_piix4()
In acpi_processor_errata_piix4(), the pointer dev is first assigned an IDE
device and then reassigned an ISA device:
dev = pci_get_subsys(..., PCI_DEVICE_ID_INTEL_82371AB, ...);
dev = pci_get_subsys(..., PCI_DEVICE_ID_INTEL_82371AB_0, ...);
If the first lookup succeeds but the second fails, dev becomes NULL. This
leads to a potential null-pointer dereference when dev_dbg() is called:
if (errata.piix4.bmisx)
dev_dbg(&dev->dev, ...);
To prevent this, use two temporary pointers and retrieve each device
independently, avoiding overwriting dev with a possible NULL value.
[ rjw: Subject adjustment, added an empty code line ] |
| In the Linux kernel, the following vulnerability has been resolved:
mm/hugetlb: restore failed global reservations to subpool
Commit a833a693a490 ("mm: hugetlb: fix incorrect fallback for subpool")
fixed an underflow error for hstate->resv_huge_pages caused by incorrectly
attributing globally requested pages to the subpool's reservation.
Unfortunately, this fix also introduced the opposite problem, which would
leave spool->used_hpages elevated if the globally requested pages could
not be acquired. This is because while a subpool's reserve pages only
accounts for what is requested and allocated from the subpool, its "used"
counter keeps track of what is consumed in total, both from the subpool
and globally. Thus, we need to adjust spool->used_hpages in the other
direction, and make sure that globally requested pages are uncharged from
the subpool's used counter.
Each failed allocation attempt increments the used_hpages counter by how
many pages were requested from the global pool. Ultimately, this renders
the subpool unusable, as used_hpages approaches the max limit.
The issue can be reproduced as follows:
1. Allocate 4 hugetlb pages
2. Create a hugetlb mount with max=4, min=2
3. Consume 2 pages globally
4. Request 3 pages from the subpool (2 from subpool + 1 from global)
4.1 hugepage_subpool_get_pages(spool, 3) succeeds.
used_hpages += 3
4.2 hugetlb_acct_memory(h, 1) fails: no global pages left
used_hpages -= 2
5. Subpool now has used_hpages = 1, despite not being able to
successfully allocate any hugepages. It believes it can now only
allocate 3 more hugepages, not 4.
With each failed allocation attempt incrementing the used counter, the
subpool eventually reaches a point where its used counter equals its
max counter. At that point, any future allocations that try to
allocate hugeTLB pages from the subpool will fail, despite the subpool
not having any of its hugeTLB pages consumed by any user.
Once this happens, there is no way to make the subpool usable again,
since there is no way to decrement the used counter as no process is
really consuming the hugeTLB pages.
The underflow issue that the original commit fixes still remains fixed
as well.
Without this fix, used_hpages would keep on leaking if
hugetlb_acct_memory() fails. |
| In the Linux kernel, the following vulnerability has been resolved:
net: dsa: microchip: Fix error path in PTP IRQ setup
If request_threaded_irq() fails during the PTP message IRQ setup, the
newly created IRQ mapping is never disposed. Indeed, the
ksz_ptp_irq_setup()'s error path only frees the mappings that were
successfully set up.
Dispose the newly created mapping if the associated
request_threaded_irq() fails at setup. |
| In the Linux kernel, the following vulnerability has been resolved:
ext4: move ext4_percpu_param_init() before ext4_mb_init()
When running `kvm-xfstests -c ext4/1k -C 1 generic/383` with the
`DOUBLE_CHECK` macro defined, the following panic is triggered:
==================================================================
EXT4-fs error (device vdc): ext4_validate_block_bitmap:423:
comm mount: bg 0: bad block bitmap checksum
BUG: unable to handle page fault for address: ff110000fa2cc000
PGD 3e01067 P4D 3e02067 PUD 0
Oops: Oops: 0000 [#1] SMP NOPTI
CPU: 0 UID: 0 PID: 2386 Comm: mount Tainted: G W
6.18.0-gba65a4e7120a-dirty #1152 PREEMPT(none)
RIP: 0010:percpu_counter_add_batch+0x13/0xa0
Call Trace:
<TASK>
ext4_mark_group_bitmap_corrupted+0xcb/0xe0
ext4_validate_block_bitmap+0x2a1/0x2f0
ext4_read_block_bitmap+0x33/0x50
mb_group_bb_bitmap_alloc+0x33/0x80
ext4_mb_add_groupinfo+0x190/0x250
ext4_mb_init_backend+0x87/0x290
ext4_mb_init+0x456/0x640
__ext4_fill_super+0x1072/0x1680
ext4_fill_super+0xd3/0x280
get_tree_bdev_flags+0x132/0x1d0
vfs_get_tree+0x29/0xd0
vfs_cmd_create+0x59/0xe0
__do_sys_fsconfig+0x4f6/0x6b0
do_syscall_64+0x50/0x1f0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
==================================================================
This issue can be reproduced using the following commands:
mkfs.ext4 -F -q -b 1024 /dev/sda 5G
tune2fs -O quota,project /dev/sda
mount /dev/sda /tmp/test
With DOUBLE_CHECK defined, mb_group_bb_bitmap_alloc() reads
and validates the block bitmap. When the validation fails,
ext4_mark_group_bitmap_corrupted() attempts to update
sbi->s_freeclusters_counter. However, this percpu_counter has not been
initialized yet at this point, which leads to the panic described above.
Fix this by moving the execution of ext4_percpu_param_init() to occur
before ext4_mb_init(), ensuring the per-CPU counters are initialized
before they are used. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: do not ASSERT() when the fs flips RO inside btrfs_repair_io_failure()
[BUG]
There is a bug report that when btrfs hits ENOSPC error in a critical
path, btrfs flips RO (this part is expected, although the ENOSPC bug
still needs to be addressed).
The problem is after the RO flip, if there is a read repair pending, we
can hit the ASSERT() inside btrfs_repair_io_failure() like the following:
BTRFS info (device vdc): relocating block group 30408704 flags metadata|raid1
------------[ cut here ]------------
BTRFS: Transaction aborted (error -28)
WARNING: fs/btrfs/extent-tree.c:3235 at __btrfs_free_extent.isra.0+0x453/0xfd0, CPU#1: btrfs/383844
Modules linked in: kvm_intel kvm irqbypass
[...]
---[ end trace 0000000000000000 ]---
BTRFS info (device vdc state EA): 2 enospc errors during balance
BTRFS info (device vdc state EA): balance: ended with status: -30
BTRFS error (device vdc state EA): parent transid verify failed on logical 30556160 mirror 2 wanted 8 found 6
BTRFS error (device vdc state EA): bdev /dev/nvme0n1 errs: wr 0, rd 0, flush 0, corrupt 10, gen 0
[...]
assertion failed: !(fs_info->sb->s_flags & SB_RDONLY) :: 0, in fs/btrfs/bio.c:938
------------[ cut here ]------------
assertion failed: !(fs_info->sb->s_flags & SB_RDONLY) :: 0, in fs/btrfs/bio.c:938
kernel BUG at fs/btrfs/bio.c:938!
Oops: invalid opcode: 0000 [#1] SMP NOPTI
CPU: 0 UID: 0 PID: 868 Comm: kworker/u8:13 Tainted: G W N 6.19.0-rc6+ #4788 PREEMPT(full)
Tainted: [W]=WARN, [N]=TEST
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014
Workqueue: btrfs-endio simple_end_io_work
RIP: 0010:btrfs_repair_io_failure.cold+0xb2/0x120
RSP: 0000:ffffc90001d2bcf0 EFLAGS: 00010246
RAX: 0000000000000051 RBX: 0000000000001000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8305cf42 RDI: 00000000ffffffff
RBP: 0000000000000002 R08: 00000000fffeffff R09: ffffffff837fa988
R10: ffffffff8327a9e0 R11: 6f69747265737361 R12: ffff88813018d310
R13: ffff888168b8a000 R14: ffffc90001d2bd90 R15: ffff88810a169000
FS: 0000000000000000(0000) GS:ffff8885e752c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
------------[ cut here ]------------
[CAUSE]
The cause of -ENOSPC error during the test case btrfs/124 is still
unknown, although it's known that we still have cases where metadata can
be over-committed but can not be fulfilled correctly, thus if we hit
such ENOSPC error inside a critical path, we have no choice but abort
the current transaction.
This will mark the fs read-only.
The problem is inside the btrfs_repair_io_failure() path that we require
the fs not to be mount read-only. This is normally fine, but if we are
doing a read-repair meanwhile the fs flips RO due to a critical error,
we can enter btrfs_repair_io_failure() with super block set to
read-only, thus triggering the above crash.
[FIX]
Just replace the ASSERT() with a proper return if the fs is already
read-only. |
| In the Linux kernel, the following vulnerability has been resolved:
io_uring/kbuf: check if target buffer list is still legacy on recycle
There's a gap between when the buffer was grabbed and when it
potentially gets recycled, where if the list is empty, someone could've
upgraded it to a ring provided type. This can happen if the request
is forced via io-wq. The legacy recycling is missing checking if the
buffer_list still exists, and if it's of the correct type. Add those
checks. |
| In the Linux kernel, the following vulnerability has been resolved:
xfs: fix undersized l_iclog_roundoff values
If the superblock doesn't list a log stripe unit, we set the incore log
roundoff value to 512. This leads to corrupt logs and unmountable
filesystems in generic/617 on a disk with 4k physical sectors...
XFS (sda1): Mounting V5 Filesystem ff3121ca-26e6-4b77-b742-aaff9a449e1c
XFS (sda1): Torn write (CRC failure) detected at log block 0x318e. Truncating head block from 0x3197.
XFS (sda1): failed to locate log tail
XFS (sda1): log mount/recovery failed: error -74
XFS (sda1): log mount failed
XFS (sda1): Mounting V5 Filesystem ff3121ca-26e6-4b77-b742-aaff9a449e1c
XFS (sda1): Ending clean mount
...on the current xfsprogs for-next which has a broken mkfs. xfs_info
shows this...
meta-data=/dev/sda1 isize=512 agcount=4, agsize=644992 blks
= sectsz=4096 attr=2, projid32bit=1
= crc=1 finobt=1, sparse=1, rmapbt=1
= reflink=1 bigtime=1 inobtcount=1 nrext64=1
= exchange=1 metadir=1
data = bsize=4096 blocks=2579968, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0, ftype=1, parent=1
log =internal log bsize=4096 blocks=16384, version=2
= sectsz=4096 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
= rgcount=0 rgsize=268435456 extents
= zoned=0 start=0 reserved=0
...observe that the log section has sectsz=4096 sunit=0, which means
that the roundoff factor is 512, not 4096 as you'd expect. We should
fix mkfs not to generate broken filesystems, but anyone can fuzz the
ondisk superblock so we should be more cautious. I think the inadequate
logic predates commit a6a65fef5ef8d0, but that's clearly going to
require a different backport. |
| In the Linux kernel, the following vulnerability has been resolved:
ublk: fix NULL pointer dereference in ublk_ctrl_set_size()
ublk_ctrl_set_size() unconditionally dereferences ub->ub_disk via
set_capacity_and_notify() without checking if it is NULL.
ub->ub_disk is NULL before UBLK_CMD_START_DEV completes (it is only
assigned in ublk_ctrl_start_dev()) and after UBLK_CMD_STOP_DEV runs
(ublk_detach_disk() sets it to NULL). Since the UBLK_CMD_UPDATE_SIZE
handler performs no state validation, a user can trigger a NULL pointer
dereference by sending UPDATE_SIZE to a device that has been added but
not yet started, or one that has been stopped.
Fix this by checking ub->ub_disk under ub->mutex before dereferencing
it, and returning -ENODEV if the disk is not available. |