CVE-2026-46035
MediumCVSS 5.5Exploitation Probability (EPSS)
Low risk6th percentile - higher than 6% of all known CVEs
Summary
A vulnerability has been identified in the Linux kernel that allows re-entry into the rmqueue() function from NMI context in UP systems, leading to corruption of the free page lists. This issue occurs when spin_trylock() always returns success, even when the lock is already held.
Risk Assessment
Organizations may be exposed to memory corruption and system instability, potentially leading to application or system crashes. In particular, UP-based systems may experience serious memory management issues.
Recommendation
It is recommended to update the Linux kernel to a version that includes a fix for this issue to avoid potential crashes and memory corruption.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: mm/page_alloc: return NULL early from alloc_frozen_pages_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, alloc_frozen_pages_nolock() called from NMI context can re-enter rmqueue() and acquire the zone lock that the interrupted context is already holding, corrupting the freelists. 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 rmqueue.isra.0+0x2a9/0xa70 get_page_from_freelist+0xeb/0x450 alloc_frozen_pages_nolock_noprof+0x111/0x1e0 allocate_slab+0x42a/0x500 ___slab_alloc+0xa7/0x4c0 kmalloc_nolock_noprof+0x164/0x310 [...] </NMI> Fix this by returning NULL early when invoked from NMI on a UP kernel.