CVE-2026-72431

In the Linux kernel, the following vulnerability has been resolved: alloc_tag: fix use-after-free in /proc/allocinfo after module unload allocinfo_start() only reinitializes the codetag iterator at position 0. For subsequent reads (position > 0), it reuses cached iterator state from the previous batch. allocinfo_stop() drops mod_lock between read batches, which allows module unload to complete and free the module memory that the cached iterator still references: CPU0 (read) CPU1 (rmmod) ---- ---- allocinfo_start(pos=0) down_read(mod_lock) allocinfo_show() ... allocinfo_stop() up_read(mod_lock) codetag_unload_module() kfree(cmod) release_module_tags() ... free_mod_mem() allocinfo_start(pos=N) down_read(mod_lock) // reuses cached iter, skips re-init allocinfo_show() ct->filename <-- UAF After free_mod_mem() frees the module's .rodata, allocinfo_show() dereferences ct->filename, ct->function which point there. Save the iterator state in allocinfo_next() and resume from it in allocinfo_start() with codetag_next_ct(), which detects module removal via idr_find() returning NULL and skips to the next module.

Package Linux Kernel
Published 2026-08-15
Last modified 2026-08-15
Patch available
Yes

Affected versions

Linux kernel versions 6.17 and later are affected. Fixed in 6.18.40, 7.1.5, 7.2-rc1 and their respective stable series.

Affected from
≥ 6.17
Fixed in
✓ 6.18.40 6.18.x ✓ 7.1.5 7.1.x ✓ 7.2-rc1

Frequently asked questions

  • What is CVE-2026-72431?

    CVE-2026-72431 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 6.17 onward and has been patched in 6.18.40, 7.1.5 and 7.2-rc1. CVE-2026-72431 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • Is there a patch available for CVE-2026-72431?

    Yes. CVE-2026-72431 has been patched. Fixed versions include 6.18.40, 7.1.5 and 7.2-rc1. If you are running Linux kernel 6.17 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-72431 actively exploited?

    No. CVE-2026-72431 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.