CVE-2026-46029
mm/slab: return NULL early from kmalloc_nolock() in NMI on UP
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.
| Vendor | linux |
| Product | linux |
| Ecosystems | |
| Industries | Technology |
| Published | May 27, 2026 |
| Last Updated | May 30, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H