CVE-2026-46029 Details
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.
A vulnerability in the Linux kernel's memory allocation function, kmalloc_nolock(), can lead to slab corruption on uniprocessor (UP) kernels) without SMP (Symmetric MultiProcessing) support. This issue arises because, on UP kernels, the spin_trylock() function always succeeds, even if a lock is already held. Consequently, when kmalloc_nolock() is called from a Non-Maskable Interrupt (NMI) context, it can disrupt the slab allocator by re-entering and seizing a lock that is already in use, causing corruption. This vulnerability has been observed with the CONFIG_DEBUG_SPINLOCK option enabled, where a specific error is triggered during testing.
Users can upgrade to the latest version of the Linux kernel where this vulnerability has been addressed. Instructions for downloading the patched version are available on the Linux kernel's official website.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
No SSVC data is available for this CVE.
References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://git.kernel.org/stable/c/5b31044e649e3e54c2caef135c09b371c2fbcd08 | kernel.org | Patch |
| https://git.kernel.org/stable/c/a8d95d274be241ad21f6523bf2d6ba0d7d7e46b7 | kernel.org | Patch |
| https://git.kernel.org/stable/c/d66553204a15bdb257d9ef8aca1e12f5fbb910b2 | kernel.org | Patch |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| NVD-CWE-noinfo | Insufficient Information to Classify Weakness | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| linux linux kernel | >= 6.18, < 6.18.27 >= 6.19, < 7.0.4 7.1 rc1 |
CPE
Remediation
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Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | kernel.org |
| Jun 16, 2026 | Initial Analysis | [email protected] |
| May 30, 2026 | CVE Modified | kernel.org |
| May 27, 2026 | New CVE Received | kernel.org |