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.
Affected versions
Linux kernel versions
6.17
and later are affected. Fixed in
6.18.40,
7.1.5,
7.2
and their respective stable series.
References
3 totalFrequently 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. 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. 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.