CVE-2025-71110

HIGHCVSS 7.8/10EPSS 0.12%

Last modified

CVE-2025-71110 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: mm/slub: reset KASAN tag in defer_free() before accessing freed memory When CONFIG_SLUB_TINY is enabled, kfree_nolock() calls kasan_slab_free() before defer_free(). On ARM64 with MTE (Memory Tagging Extension), kasan_slab_free() poisons the memory and changes the tag from the original (e.g., 0xf3) to a poison tag (0xfe). When defer_free() then tries to write to the freed object to build the deferred free list via llist_add(), the pointer still has the old tag, causing a tag mismatch and triggering a KASAN use-after-free report: BUG: KASAN: slab-use-after-free in defer_free+0x3c/0xbc mm/slub.c:6537 Write at addr f3f000000854f020 by task kworker/u8:6/983 Pointer tag: [f3], memory tag: [fe] Fix this by calling kasan_reset_tag() before accessing the freed memory. This is safe because defer_free() is part of the allocator itself and is expected to manipulate freed memory for bookkeeping purposes.. EPSS estimates a 0.12% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: mm/slub: reset KASAN tag in defer_free() before accessing freed memory When CONFIG_SLUB_TINY is enabled, kfree_nolock() calls kasan_slab_free() before defer_free(). On ARM64 with MTE (Memory Tagging Extension), kasan_slab_free() poisons the memory and changes the tag from the original (e.g., 0xf3) to a poison tag (0xfe). When defer_free() then tries to write to the freed object to build the deferred free list via llist_add(), the pointer still has the old tag, causing a tag mismatch and triggering a KASAN use-after-free report: BUG: KASAN: slab-use-after-free in defer_free+0x3c/0xbc mm/slub.c:6537 Write at addr f3f000000854f020 by task kworker/u8:6/983 Pointer tag: [f3], memory tag: [fe] Fix this by calling kasan_reset_tag() before accessing the freed memory. This is safe because defer_free() is part of the allocator itself and is expected to manipulate freed memory for bookkeeping purposes.

Metrics

CVSS 3.1
7.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability
0.12%

2.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersionsUpdate
LinuxLinux Kernel>= 6.18.1, < 6.18.3
LinuxLinux Kernel6.18
LinuxLinux Kernel6.19Rc1

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2025-71110?
In the Linux kernel, the following vulnerability has been resolved: mm/slub: reset KASAN tag in defer_free() before accessing freed memory When CONFIG_SLUB_TINY is enabled, kfree_nolock() calls kasan_slab_free() before defer_free(). On ARM64 with MTE (Memory Tagging Extension), kasan_slab_free() poisons the memory and changes the tag from the original (e.g., 0xf3) to a poison tag (0xfe). When defer_free() then tries to write to the freed object to build the deferred free list via llist_add(), the pointer still has the old tag, causing a tag mismatch and triggering a KASAN use-after-free report: BUG: KASAN: slab-use-after-free in defer_free+0x3c/0xbc mm/slub.c:6537 Write at addr f3f000000854f020 by task kworker/u8:6/983 Pointer tag: [f3], memory tag: [fe] Fix this by calling kasan_reset_tag() before accessing the freed memory. This is safe because defer_free() is part of the allocator itself and is expected to manipulate freed memory for bookkeeping purposes.
How severe is CVE-2025-71110?
CVE-2025-71110 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.12% probability of exploitation in the next 30 days.
How do I fix CVE-2025-71110?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-71110?

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Source: NVD / NIST