CVE-2026-72431

alloc_tag: fix use-after-free in /proc/allocinfo after module unload

N/A
Published: August 15, 2026 at 05:56 AM UTC
Updated: August 17, 2026 at 06:19 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
N/A
Exploit prediction
EPSS 0.2%

Description

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

6.17 ≤ v < 6.18.406.17 ≤ v < 7.1.56.17 ≤ v < 7.26.179f44df50fee4d2f6cb374177244ccfa9f0a5cc95
Vendor states this is fixed in 008ceffd44040f809aead6d7bef7cb1210c4149a (fixed)
Vendor states this is fixed in 2956268efc457cb05d29c1bf94de1e8e684d7bbc (fixed)
Vendor states this is fixed in 37e3e8a2c3bfdd503209f043f8bbfbdcf5a1d92f (fixed)
Vendor states this is fixed in 6.17 (unaffected)
Vendor states this is fixed in 6.18.40 (unaffected)
Vendor states this is fixed in 7.1.5 (unaffected)
Vendor states this is fixed in 7.2 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

Quick Info

StatusRECEIVED

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