locking/rtmutex: Skip remove_waiter() when waiter is not enqueued
Summary
| CVE | CVE-2026-53163 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-06-25 09:16:33 UTC |
| Updated | 2026-07-04 12:16:59 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: locking/rtmutex: Skip remove_waiter() when waiter is not enqueued syzbot triggered the following splat in remove_waiter() via FUTEX_CMP_REQUEUE_PI: KASAN: null-ptr-deref in range [0x0000000000000a88-0x0000000000000a8f] class_raw_spinlock_constructor remove_waiter+0x159/0x1200 kernel/locking/rtmutex.c:1561 rt_mutex_start_proxy_lock+0x103/0x120 futex_requeue+0x10e4/0x20d0 __x64_sys_futex+0x34f/0x4d0 task_blocks_on_rt_mutex() does not arm the waiter upon deadlock detection, leaving waiter->task nil, where 3bfdc63936dd ("rtmutex: Use waiter::task instead of current in remove_waiter()") made this fatal. Furthermore, rt_mutex_start_proxy_lock() should not be calling into remove_waiter() upon a successfully grabbing the rtmutex. 1a1fb985f2e2 ("futex: Handle early deadlock return correctly"), moved the remove_waiter() out of __rt_mutex_start_proxy_lock() (where 'ret' was only ever 0 or < 0) into the wrapper. Tighten this check to account for try_to_take_rt_mutex(). |
Risk And Classification
EPSS: 0.001730000 probability, percentile 0.070010000 (date 2026-07-03)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected d8cce4773c2b23d819baf5abedc62f7b430e8745 4afda3a1da02129568a3a2f1898aa13e6763bcba git | Not specified |
| CNA | Linux | Linux | affected 8a1fc8d698ac5e5916e3082a0f74450d71f9611f 6707d7e0b71748cb3cd95bad81dae5fe1b3c8f48 git | Not specified |
| CNA | Linux | Linux | affected 6d52dfcb2a5db86e346cf51f8fcf2071b8085166 5799f9bd7fee40370b93ab1ddf001cdc7017c14d git | Not specified |
| CNA | Linux | Linux | affected 3fb7394a837740770f0d6b4b30567e60786a63f2 a388e3dfaf9538a680de5ed43a8ebb5dd45b6e53 git | Not specified |
| CNA | Linux | Linux | affected 88614876370aac8ad1050ad785a4c095ba17ac11 55363fa0a04524d11efeaadee734d2db1756ed27 git | Not specified |
| CNA | Linux | Linux | affected 3bfdc63936dd4773109b7b8c280c0f3b5ae7d349 40a25d59e85b3c8709ac2424d44f65610467871e git | Not specified |
| CNA | Linux | Linux | affected 6.1.175 6.1.177 semver | Not specified |
| CNA | Linux | Linux | affected 6.6.140 6.6.144 semver | Not specified |
| CNA | Linux | Linux | affected 6.12.86 6.12.95 semver | Not specified |
| CNA | Linux | Linux | affected 6.18.27 6.18.36 semver | Not specified |
| CNA | Linux | Linux | affected 7.0.4 7.0.13 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/6707d7e0b71748cb3cd95bad81dae5fe1b3c8f48 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/4afda3a1da02129568a3a2f1898aa13e6763bcba | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/55363fa0a04524d11efeaadee734d2db1756ed27 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/5799f9bd7fee40370b93ab1ddf001cdc7017c14d | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/a388e3dfaf9538a680de5ed43a8ebb5dd45b6e53 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/40a25d59e85b3c8709ac2424d44f65610467871e | 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.