CVE-2026-99256
In the Linux kernel, the following vulnerability has been resolved: dm cache: fix issue with background work locking dm cache used a rw_semaphore for backgroun…
Impact
In the Linux kernel, the following vulnerability has been resolved: dm cache: fix issue with background work locking dm cache used a rw_semaphore for background_work_lock. Write locks on rw_semaphores have strict owner semantics, but there was no guarantee that the process that locked background_work_lock was the same process that unlocked it. This can be easily seen using a kernel compiled with CONFIG_DEBUG_RWSEMS. Given a dm cache device <cache>, run: 'dmsetup suspend <cache> && dmsetup resume <cache>'. This will trigger a kernel warning: DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)) triggered by cache_resume(). To fix this, switch from a rw_semaphore to a spinlock and a wait queue. dm cache already has a wait queue and associated counter, migration_wait and nr_allocated_migrations, that was getting woken up when background work was getting completed, but wasn't actually used by anything. This is replaced by the background_work queue and counter.
Affected products · Linux
| Product | Affected versions |
|---|---|
| Linux | from b29d4986d0da1a27cd35917cdb433672f5c95d7f before 0c7a8cad7c96012a9157a189649e569d0390f384 from b29d4986d0da1a27cd35917cdb433672f5c95d7f before f5db935d257023c3ef410bd39163b949b0e5a55d from b29d4986d0da1a27cd35917cdb433672f5c95d7f before 6290507ecc0dd6dd40759729cbbbd49b1d2a63c4 from b29d4986d0da1a27cd35917cdb433672f5c95d7f before 8433fd005c25fd127021f67c9144a879fb585572 from b29d4986d0da1a27cd35917cdb433672f5c95d7f before 2f2cfa16dd0f4179bb988139dd37d00a42324f6c from b29d4986d0da1a27cd35917cdb433672f5c95d7f before 73df2ff409f3db95029982fe3656329568e3715d |
References
- NVD record
- CVE.org record
- GitHub advisory
- https://git.kernel.org/stable/c/0c7a8cad7c96012a9157a189649e569d0390f384
- https://git.kernel.org/stable/c/f5db935d257023c3ef410bd39163b949b0e5a55d
- https://git.kernel.org/stable/c/6290507ecc0dd6dd40759729cbbbd49b1d2a63c4
- https://git.kernel.org/stable/c/8433fd005c25fd127021f67c9144a879fb585572
- https://git.kernel.org/stable/c/2f2cfa16dd0f4179bb988139dd37d00a42324f6c
- https://git.kernel.org/stable/c/73df2ff409f3db95029982fe3656329568e3715d
- https://git.kernel.org/stable/c/104f09e02038b0fc6bbb718b3976af029e15c1d0
- https://git.kernel.org/stable/c/bc9781c0247de107876f32929f1637db93a42b34
- https://github.com/advisories/GHSA-pr5p-x5rg-2942
- https://nvd.nist.gov/vuln/detail/CVE-2026-99256