CVE-2026-31657

In the Linux kernel, the following vulnerability has been resolved: batman-adv: hold claim backbone gateways by reference batadv_bla_add_claim() can replace claim->backbone_gw and drop the old gateway's last reference while readers still follow the pointer. The netlink claim dump path dereferences claim->backbone_gw->orig and takes claim->backbone_gw->crc_lock without pinning the underlying backbone gateway. batadv_bla_check_claim() still has the same naked pointer access pattern. Reuse batadv_bla_claim_get_backbone_gw() in both readers so they operate on a stable gateway reference until the read-side work is complete. This keeps the dump and claim-check paths aligned with the lifetime rules introduced for the other BLA claim readers.

CVSS 3.1

9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

0.4% chance of exploitation in the next 30 days; higher than 33% of CVEs (scores of 2026-10-25)

CWEs

CWE-476, CWE-416

Published

2026-04-24

Modified

2026-10-19

Record from

the NVD, synced 2026-10-21

Affected

• linux:linux_kernel

References

• https://git.kernel.org/stable/c/1f2dc36c297d27733f1b380ea644cf15a361bd7b
• https://git.kernel.org/stable/c/2f55b58b5a0bbed192d60c444a45a49cdf1b545f
• https://git.kernel.org/stable/c/4dee4c0688443aaf5bbec74aa203c851d1d53c35
• https://git.kernel.org/stable/c/5202f071b367ffbc8e279fc7a00db14f5e587f52
• https://git.kernel.org/stable/c/69d1ce9c72eca91203ffdb8d08bacd511100aec6

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