7.8

CVE-2026-23415

futex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy()

In the Linux kernel, the following vulnerability has been resolved:

futex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy()

During futex_key_to_node_opt() execution, vma->vm_policy is read under
speculative mmap lock and RCU. Concurrently, mbind() may call
vma_replace_policy() which frees the old mempolicy immediately via
kmem_cache_free().

This creates a race where __futex_key_to_node() dereferences a freed
mempolicy pointer, causing a use-after-free read of mpol->mode.

[  151.412631] BUG: KASAN: slab-use-after-free in __futex_key_to_node (kernel/futex/core.c:349)
[  151.414046] Read of size 2 at addr ffff888001c49634 by task e/87

[  151.415969] Call Trace:

[  151.416732]  __asan_load2 (mm/kasan/generic.c:271)
[  151.416777]  __futex_key_to_node (kernel/futex/core.c:349)
[  151.416822]  get_futex_key (kernel/futex/core.c:374 kernel/futex/core.c:386 kernel/futex/core.c:593)

Fix by adding rcu to __mpol_put().
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Linux ≫ Linux Kernel Version >= 6.16.1 < 6.18.21
Linux ≫ Linux Kernel Version >= 6.19 < 6.19.11
Linux ≫ Linux Kernel Version6.16 Update-
Linux ≫ Linux Kernel Version7.0 Updaterc1
Linux ≫ Linux Kernel Version7.0 Updaterc2
Linux ≫ Linux Kernel Version7.0 Updaterc3
Linux ≫ Linux Kernel Version7.0 Updaterc4
Linux ≫ Linux Kernel Version7.0 Updaterc5
Linux ≫ Linux Kernel Version7.0 Updaterc6
Linux ≫ Linux Kernel Version7.0 Updaterc7
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EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.02% 0.033
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
nvd@nist.gov 7.8 1.8 5.9
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
416baaa9-dc9f-4396-8d5f-8c081fb06d67 7.8 1.8 5.9
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE-416 Use After Free

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.