CVE-2026-72252

Summary

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

netfilter: nft_set_pipapo: don't leak bad clone into future transaction

On memory allocation failure the cloned nft_pipapo_match can enter a bad state:

  • some fields can have their lookup tables resized while others did not
  • bits might have been toggled
  • scratch map can be undersized which also means m->bsize_max can be lower than what is required

This means that the next insertion in the same batch can trigger out-of-bounds writes.

Furthermore, a failure in the first can result in the bad clone to leak into the next transaction because the abort callback is never executed in this case (the upper layer saw an error and no attempt to allocate a transactional request was made).

Record a state for the nft_pipapo_match structure:

  • NEW (pristine clone)
  • MOD (modified clone with good state)
  • ERR (potentially bogus content)

Then make it so that deletes and insertions fail when the clone entered ERR state.

In case the very first insert attempt results in an error, free the clone right away.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux3c4287f62044a90e73a561aa05fc46e62da173da < 047e813324eac2ac60cddfb58bcdbd0144eadb09affected
LinuxLinux3c4287f62044a90e73a561aa05fc46e62da173da < 610e3b73efaec3dd81a95dcda2421ad7d9795bd0affected
LinuxLinux3c4287f62044a90e73a561aa05fc46e62da173da < 02b6b0e892aea582590671796fd6eff5b93ea93faffected
LinuxLinux3c4287f62044a90e73a561aa05fc46e62da173da < e74f9680e1b64872a51cc7b5bda1edaaa08aa51faffected
LinuxLinux3c4287f62044a90e73a561aa05fc46e62da173da < 47e65eff50691f0a5b79d325e28d83ec1da43bcfaffected
LinuxLinux5.6affected
LinuxLinux0 < 5.6unaffected
LinuxLinux6.6.148 <= 6.6.*unaffected
LinuxLinux6.12.97 <= 6.12.*unaffected
LinuxLinux6.18.40 <= 6.18.*unaffected
LinuxLinux7.1.5 <= 7.1.*unaffected
LinuxLinux7.2 <= *unaffected

Weaknesses

References