CVE-2026-98631 PUBLISHED

xsk: Use a 32-bit compare in xsk_map_gen_lookup

Assigner: Linux
Reserved: 25.09.2026 Published: 18.10.2026 Updated: 18.10.2026

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

xsk: Use a 32-bit compare in xsk_map_gen_lookup

xsk_map_gen_lookup() loads a u32 key and compares it with max_entries using BPF_JMP_IMM. BPF immediates are sign-extended to 64 bits, so a max_entries value of 0x80000000 or higher becomes a threshold larger than every zero-extended 32-bit key. An out-of-range index then skips the bounds check and the generated lookup reads past xsk_map[].

Compare with BPF_JMP32_IMM so the check stays in 32-bit unsigned range.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from e65650f291ee72fc578d6346080fc4699204ef2c to c6d5c582d55a8f229d75e98d62eaa065b0deb18d (excl.)
  • affected from e65650f291ee72fc578d6346080fc4699204ef2c to 227ec890559e922e235eb543646e3bf0bd8269b0 (excl.)
  • affected from e65650f291ee72fc578d6346080fc4699204ef2c to 11d9be35c1f4233798e99be98bc474f83a254c6c (excl.)
  • affected from e65650f291ee72fc578d6346080fc4699204ef2c to 123f90f394ca404ab8796a7c8072ff7fa5b65a9c (excl.)
  • affected from e65650f291ee72fc578d6346080fc4699204ef2c to 36461e58f88a1b723f86693f437ac12e60ff4363 (excl.)
  • affected from e65650f291ee72fc578d6346080fc4699204ef2c to b5c0cff0c5331582ab01c4c423731453a8381acc (excl.)
  • affected from e65650f291ee72fc578d6346080fc4699204ef2c to 3c1e0a4bc156b8d5c5772dbc76b9ea74dce5ca24 (excl.)
  • affected from e65650f291ee72fc578d6346080fc4699204ef2c to 70504de0bb627848667207bec7ccfd647deb8814 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 5.5 is affected
  • unaffected from 0 to 5.5 (excl.)
  • unaffected from 5.10.271 to 5.10.* (incl.)
  • unaffected from 5.15.222 to 5.15.* (incl.)
  • unaffected from 6.1.189 to 6.1.* (incl.)
  • unaffected from 6.6.158 to 6.6.* (incl.)
  • unaffected from 6.12.112 to 6.12.* (incl.)
  • unaffected from 6.18.55 to 6.18.* (incl.)
  • unaffected from 7.2.9 to 7.2.* (incl.)
  • unaffected from 7.3-rc5 to * (incl.)

References