CVE-2026-46029
Description
In the Linux kernel, the following vulnerability has been resolved: mm/slab: return NULL early from kmalloc_nolock() in NMI on UP On UP kernels (!CONFIG_SMP), spin_trylock() is a no-op that unconditionally succeeds even when the lock is already held. As a result, kmalloc_nolock() called from NMI context can re-enter the slab allocator and acquire n->list_lock that the interrupted context is already holding, corrupting slab state. With CONFIG_DEBUG_SPINLOCK on UP, the following BUG is triggered with the slub_kunit test module: BUG: spinlock trylock failure on UP on CPU#0, kunit_try_catch/243 [...] Call Trace: <NMI> dump_stack_lvl+0x3f/0x60 do_raw_spin_trylock+0x41/0x50 _raw_spin_trylock+0x24/0x50 get_from_partial_node+0x120/0x4d0 ___slab_alloc+0x8a/0x4c0 kmalloc_nolock_noprof+0x164/0x310 [...] </NMI> Fix this by returning NULL early when invoked from NMI on a UP kernel.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or โ if you've already worked around this in production โ publish your fix to the community-verified tier.
โ Propose a mitigation on Community โ Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
SUSE Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| โ | Affected | โ |
Debian Fixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Fixed | 0 |
| sid | Fixed | 7.0.4-1 |
| forky | Fixed | 7.0.4-1 |
| bullseye | Fixed | 0 |
| bookworm | Fixed | 0 |
References
- https://git.kernel.org/stable/c/a8d95d274be241ad21f6523bf2d6ba0d7d7e46b7
- https://git.kernel.org/stable/c/d66553204a15bdb257d9ef8aca1e12f5fbb910b2
- https://git.kernel.org/stable/c/5b31044e649e3e54c2caef135c09b371c2fbcd08
- https://security-tracker.debian.org/tracker/CVE-2026-46029
- https://www.suse.com/security/cve/CVE-2026-46029.html
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.