CVE-2026-31657

CRITICAL

batman-adv: hold claim backbone gateways by reference

Title source: cna
STIX 2.1

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.

Scores

CVSS v3 9.8
EPSS 0.0008
EPSS Percentile 22.3%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Details

CWE
CWE-476
Status published
Products (17)
Linux/Linux < 3.5
Linux/Linux 23721387c409087fd3b97e274f34d3ddc0970b74 - 1f2dc36c297d27733f1b380ea644cf15a361bd7b
Linux/Linux 23721387c409087fd3b97e274f34d3ddc0970b74 - 2f55b58b5a0bbed192d60c444a45a49cdf1b545f
Linux/Linux 23721387c409087fd3b97e274f34d3ddc0970b74 - 4dee4c0688443aaf5bbec74aa203c851d1d53c35
Linux/Linux 23721387c409087fd3b97e274f34d3ddc0970b74 - 7962b522222628596ca9ecc8722efc95367aadbd
Linux/Linux 23721387c409087fd3b97e274f34d3ddc0970b74 - 82d8701b2c930d0e96b0dbc9115a218d791cb0d2
Linux/Linux 23721387c409087fd3b97e274f34d3ddc0970b74 - f4858832ddef2f39f21e30b7226bbcd3c4b2bc96
Linux/Linux 3.5
Linux/Linux 6.1.169 - 6.1.*
Linux/Linux 6.12.82 - 6.12.*
... and 7 more
Published Apr 24, 2026
Tracked Since Apr 24, 2026