dm cache: fix null-deref with concurrent writes in passthrough mode
Summary
| CVE | CVE-2026-53064 |
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-06-24 17:17:19 UTC |
| Updated | 2026-06-24 17:17:19 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved:
dm cache: fix null-deref with concurrent writes in passthrough mode
In passthrough mode, when dm-cache starts to invalidate a cache
entry and bio prison cell lock fails due to concurrent write to
the same cached block, mg->cell remains NULL. The error path in
invalidate_complete() attempts to unlock and free the cell
unconditionally, causing a NULL pointer dereference:
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 UID: 0 PID: 134 Comm: fio Not tainted 6.19.0-rc7 #3 PREEMPT
RIP: 0010:dm_cell_unlock_v2+0x3f/0x210
<snip>
Call Trace:
invalidate_complete+0xef/0x430
map_bio+0x130f/0x1a10
cache_map+0x320/0x6b0
__map_bio+0x458/0x510
dm_submit_bio+0x40e/0x16d0
__submit_bio+0x419/0x870
<snip>
Reproduce steps:
1. Create a cache device
dmsetup create cmeta --table "0 8192 linear /dev/sdc 0"
dmsetup create cdata --table "0 131072 linear /dev/sdc 8192"
dmsetup create corig --table "0 262144 linear /dev/sdc 262144"
dd if=/dev/zero of=/dev/mapper/cmeta bs=4k count=1 oflag=direct
dmsetup create cache --table "0 262144 cache /dev/mapper/cmeta \
/dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0"
2. Promote the first data block into cache
fio --filename=/dev/mapper/cache --name=populate --rw=write --bs=4k \
--direct=1 --size=64k
3. Reload the cache into passthrough mode
dmsetup suspend cache
dmsetup reload cache --table "0 262144 cache /dev/mapper/cmeta \
/dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 passthrough smq 0"
dmsetup resume cache
4. Write to the first cached block concurrently
fio --filename=/dev/mapper/cache --name test --rw=randwrite --bs=4k \
--randrepeat=0 --direct=1 --numjobs=2 --size 64k
Fix by checking if mg->cell is valid before attempting to unlock it. |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|
| CNA |
Linux |
Linux |
affected b29d4986d0da1a27cd35917cdb433672f5c95d7f 01264a6a3a3ad7ac1d73443299cd5a9568002454 git |
Not specified |
| CNA |
Linux |
Linux |
affected b29d4986d0da1a27cd35917cdb433672f5c95d7f ee38fb00e1a80f46a4990e38f25ecb04ae7b7417 git |
Not specified |
| CNA |
Linux |
Linux |
affected b29d4986d0da1a27cd35917cdb433672f5c95d7f c7fb6bc864c4910b344dafa36dd5028e9b980768 git |
Not specified |
| CNA |
Linux |
Linux |
affected b29d4986d0da1a27cd35917cdb433672f5c95d7f 0aa745fea1f8dc81bcdd0a45e215b6706727b482 git |
Not specified |
| CNA |
Linux |
Linux |
affected b29d4986d0da1a27cd35917cdb433672f5c95d7f a2635d541a93fd111e743cf14b6275dc81be2abc git |
Not specified |
| CNA |
Linux |
Linux |
affected b29d4986d0da1a27cd35917cdb433672f5c95d7f 25dcc1989c194ba2b5fb6d03cbb9b83814ac0d15 git |
Not specified |
| CNA |
Linux |
Linux |
affected b29d4986d0da1a27cd35917cdb433672f5c95d7f df3b8ef06cc62de4fca5d2108e285085b3cffd44 git |
Not specified |
| CNA |
Linux |
Linux |
affected b29d4986d0da1a27cd35917cdb433672f5c95d7f 7d1f98d668ee34c1d15bdc0420fdd062f24a27c0 git |
Not specified |
| CNA |
Linux |
Linux |
affected 4.12 |
Not specified |
| CNA |
Linux |
Linux |
unaffected 4.12 semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 5.10.258 5.10.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 5.15.209 5.15.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.1.175 6.1.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.6.141 6.6.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.12.91 6.12.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.18.33 6.18.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.0.10 7.0.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.1 * original_commit_for_fix |
Not specified |
References
| Reference | Source | Link | Tags |
|---|
| git.kernel.org/stable/c/01264a6a3a3ad7ac1d73443299cd5a9568002454 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/25dcc1989c194ba2b5fb6d03cbb9b83814ac0d15 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/ee38fb00e1a80f46a4990e38f25ecb04ae7b7417 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/0aa745fea1f8dc81bcdd0a45e215b6706727b482 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/a2635d541a93fd111e743cf14b6275dc81be2abc |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/7d1f98d668ee34c1d15bdc0420fdd062f24a27c0 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/df3b8ef06cc62de4fca5d2108e285085b3cffd44 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/c7fb6bc864c4910b344dafa36dd5028e9b980768 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| CVE Program record |
CVE.ORG |
www.cve.org |
canonical |
| NVD vulnerability detail |
NVD |
nvd.nist.gov |
canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.