netfilter: nft_set_pipapo: prevent overflow in lookup table allocation

Summary

In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_set_pipapo: prevent overflow in lookup table allocation When calculating the lookup table size, ensure the following multiplication does not overflow: • desc->field_len[] maximum value is U8_MAX multiplied by NFT_PIPAPO_GROUPS_PER_BYTE(f) that can be 2, worst case. • NFT_PIPAPO_BUCKETS(f->bb) is 2^8, worst case. • sizeof(unsigned long), from sizeof(*f->lt), lt in struct nft_pipapo_field. Then, use check_mul_overflow() to multiply by bucket size and then use check_add_overflow() to the alignment for avx2 (if needed). Finally, add lt_size_check_overflow() helper and use it to consolidate this. While at it, replace leftover allocation using the GFP_KERNEL to GFP_KERNEL_ACCOUNT for consistency, in pipapo_resize().

Timeline

1. Jul 3, 2025, 8:36 AM UTCCVE published
2. Oct 15, 2026, 9:47 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: total

3. Oct 15, 2026, 9:52 PM UTCRecord last updated

Affected versions

• Linux Linux

  From 3c4287f62044a90e73a561aa05fc46e62da173da · fixed in 91edc076439c9e2f34b176149f1c84a47a8ec32f; From 3c4287f62044a90e73a561aa05fc46e62da173da · fixed in a9e757473561da93c6a4136f0e59aba91ec777fc; From 3c4287f62044a90e73a561aa05fc46e62da173da · fixed in c1360ac8156c0a3f2385baef91d8d26fd9d39701; From 3c4287f62044a90e73a561aa05fc46e62da173da · fixed in 43fe1181f738295624696ae9ff611790edb65b5e; From 3c4287f62044a90e73a561aa05fc46e62da173da · fixed in 4c5c6aa9967dbe55bd017bb509885928d0f31206

• Linux Linux

  5.6

• KernelLinux

  From 5.6.0 · fixed in 6.1.167; From 6.2.0 · fixed in 6.6.125; From 6.7.0 · fixed in 6.12.34; From 6.13.0 · fixed in 6.15.3

References 5