CVE-2026-31657

high

Description

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.

References

https://git.kernel.org/stable/c/f4858832ddef2f39f21e30b7226bbcd3c4b2bc96

https://git.kernel.org/stable/c/82d8701b2c930d0e96b0dbc9115a218d791cb0d2

https://git.kernel.org/stable/c/7962b522222628596ca9ecc8722efc95367aadbd

https://git.kernel.org/stable/c/4dee4c0688443aaf5bbec74aa203c851d1d53c35

https://git.kernel.org/stable/c/2f55b58b5a0bbed192d60c444a45a49cdf1b545f

https://git.kernel.org/stable/c/1f2dc36c297d27733f1b380ea644cf15a361bd7b

Details

Source: Mitre, NVD

Published: 2026-04-24

Updated: 2026-04-24

Risk Information

CVSS v2

Base Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N

Severity: Medium

CVSS v3

Base Score: 7.1

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Severity: High