CVE-2026-46035

Name	CVE-2026-46035
Description	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.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
linux (PTS)	bullseye	5.10.223-1	fixed
	bullseye (security)	5.10.257-1	fixed
	bookworm	6.1.170-3	fixed
	bookworm (security)	6.1.174-1	fixed
	trixie	6.12.86-1	fixed
	trixie (security)	6.12.90-2	fixed
	forky	7.0.10-1	fixed
	sid	7.0.12-2	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version
linux	source	bullseye	(not affected)
linux	source	bookworm	(not affected)
linux	source	trixie	(not affected)
linux	source	(unstable)	7.0.4-1

Notes

[trixie] - linux <not-affected> (Vulnerable code not present)
[bookworm] - linux <not-affected> (Vulnerable code not present)
[bullseye] - linux <not-affected> (Vulnerable code not present)
https://git.kernel.org/linus/620b46ed6ae17c8438d889c8c0cfddab36a1476c (7.1-rc2)