Skip to main content
cve.nowby Sazabi
← All vulnerabilities
CVE-2026-31570

can: gw: fix OOB heap access in cgw_csum_crc8_rel()

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 5.10.253, 5.15.203, 6.1.168, 6.6.131, 6.12.80, and 2 more
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: no
  • Technical impact: total

Summary

In the Linux kernel, the following vulnerability has been resolved: can: gw: fix OOB heap access in cgw_csum_crc8_rel() cgw_csum_crc8_rel() correctly computes bounds-safe indices via calc_idx(): int from = calc_idx(crc8->from_idx, cf->len); int to = calc_idx(crc8->to_idx, cf->len); int res = calc_idx(crc8->result_idx, cf->len); if (from < 0 || to < 0 || res < 0) return; However, the loop and the result write then use the raw s8 fields directly instead of the computed variables: for (i = crc8->from_idx; ...) /* BUG: raw negative index */ cf->data[crc8->result_idx] = ...; /* BUG: raw negative index */ With from_idx = to_idx = result_idx = -64 on a 64-byte CAN FD frame, calc_idx(-64, 64) = 0 so the guard passes, but the loop iterates with i = -64, reading cf->data[-64], and the write goes to cf->data[-64]. This write might end up to 56 (7.0-rc) or 40 (<= 6.19) bytes before the start of the canfd_frame on the heap. The companion function cgw_csum_xor_rel() uses `from`/`to`/`res` correctly throughout; fix cgw_csum_crc8_rel() to match. Confirmed with KASAN on linux-7.0-rc2: BUG: KASAN: slab-out-of-bounds in cgw_csum_crc8_rel+0x515/0x5b0 Read of size 1 at addr ffff8880076619c8 by task poc_cgw_oob/62 To configure the can-gw crc8 checksums CAP_NET_ADMIN is needed.

Timeline

  1. CVE published
  2. CISA SSVC assessment

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

  3. Record last updated

Affected versions

  • Linux Linux

    From 456a8a646b2563438c16a9b27decf9aa717f1ebb · fixed in e7c99348b0612b2bc02d5ce6ff9873261cc7605f; From 456a8a646b2563438c16a9b27decf9aa717f1ebb · fixed in 999ca48d55a8a46da21519db7e834e5867200379; From 456a8a646b2563438c16a9b27decf9aa717f1ebb · fixed in a025283d7f7404c739225e457fb99db2368bb544; From 456a8a646b2563438c16a9b27decf9aa717f1ebb · fixed in 54ecdf76a55e75c1f5085e440f8ab671a3283ef5; From 456a8a646b2563438c16a9b27decf9aa717f1ebb · fixed in c4e8eaa75fa0b6bcbfa5356d6195c4ad0e05e57a; From 456a8a646b2563438c16a9b27decf9aa717f1ebb · fixed in 84f8b76d24273175a22713e83e90874e1880d801; From 456a8a646b2563438c16a9b27decf9aa717f1ebb · fixed in 66b689efd08227da2c5ca49b58b30a95d23c695a; From 456a8a646b2563438c16a9b27decf9aa717f1ebb · fixed in b9c310d72783cc2f30d103eed83920a5a29c671a

  • Linux Linux

    5.4

  • KernelLinux

    From 5.4.0 · fixed in 5.10.253; From 5.11.0 · fixed in 5.15.203; From 5.16.0 · fixed in 6.1.168; From 6.2.0 · fixed in 6.6.131; From 6.7.0 · fixed in 6.12.80; From 6.13.0 · fixed in 6.18.21; From 6.19.0 · fixed in 6.19.11

References 8

git.kernel.org