can: gw: fix OOB heap access in cgw_csum_crc8_rel()
Summary
| CVE | CVE-2026-31570 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-04-24 15:16:31 UTC |
| Updated | 2026-04-24 17:51:40 UTC |
| Description | 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. |
Risk And Classification
EPSS: 0.000240000 probability, percentile 0.068020000 (date 2026-04-25)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 456a8a646b2563438c16a9b27decf9aa717f1ebb e7c99348b0612b2bc02d5ce6ff9873261cc7605f git | Not specified |
| CNA | Linux | Linux | affected 456a8a646b2563438c16a9b27decf9aa717f1ebb 999ca48d55a8a46da21519db7e834e5867200379 git | Not specified |
| CNA | Linux | Linux | affected 456a8a646b2563438c16a9b27decf9aa717f1ebb a025283d7f7404c739225e457fb99db2368bb544 git | Not specified |
| CNA | Linux | Linux | affected 456a8a646b2563438c16a9b27decf9aa717f1ebb 54ecdf76a55e75c1f5085e440f8ab671a3283ef5 git | Not specified |
| CNA | Linux | Linux | affected 456a8a646b2563438c16a9b27decf9aa717f1ebb c4e8eaa75fa0b6bcbfa5356d6195c4ad0e05e57a git | Not specified |
| CNA | Linux | Linux | affected 456a8a646b2563438c16a9b27decf9aa717f1ebb 84f8b76d24273175a22713e83e90874e1880d801 git | Not specified |
| CNA | Linux | Linux | affected 456a8a646b2563438c16a9b27decf9aa717f1ebb 66b689efd08227da2c5ca49b58b30a95d23c695a git | Not specified |
| CNA | Linux | Linux | affected 456a8a646b2563438c16a9b27decf9aa717f1ebb b9c310d72783cc2f30d103eed83920a5a29c671a git | Not specified |
| CNA | Linux | Linux | affected 5.4 | Not specified |
| CNA | Linux | Linux | unaffected 5.4 semver | Not specified |
| CNA | Linux | Linux | unaffected 5.10.253 5.10.* semver | Not specified |
| CNA | Linux | Linux | unaffected 5.15.203 5.15.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.1.168 6.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.131 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.80 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.21 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.19.11 6.19.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.0 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/c4e8eaa75fa0b6bcbfa5356d6195c4ad0e05e57a | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/84f8b76d24273175a22713e83e90874e1880d801 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/66b689efd08227da2c5ca49b58b30a95d23c695a | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/54ecdf76a55e75c1f5085e440f8ab671a3283ef5 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/b9c310d72783cc2f30d103eed83920a5a29c671a | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/e7c99348b0612b2bc02d5ce6ff9873261cc7605f | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/999ca48d55a8a46da21519db7e834e5867200379 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/a025283d7f7404c739225e457fb99db2368bb544 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.