CVE-2026-31657 PUBLISHED

batman-adv: hold claim backbone gateways by reference

Assigner: Linux
Reserved: 09.03.2026 Published: 24.04.2026 Updated: 24.04.2026

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.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 23721387c409087fd3b97e274f34d3ddc0970b74 to f4858832ddef2f39f21e30b7226bbcd3c4b2bc96 (excl.)
  • affected from 23721387c409087fd3b97e274f34d3ddc0970b74 to 2f55b58b5a0bbed192d60c444a45a49cdf1b545f (excl.)
  • affected from 23721387c409087fd3b97e274f34d3ddc0970b74 to 7962b522222628596ca9ecc8722efc95367aadbd (excl.)
  • affected from 23721387c409087fd3b97e274f34d3ddc0970b74 to 4dee4c0688443aaf5bbec74aa203c851d1d53c35 (excl.)
  • affected from 23721387c409087fd3b97e274f34d3ddc0970b74 to 1f2dc36c297d27733f1b380ea644cf15a361bd7b (excl.)
  • affected from 23721387c409087fd3b97e274f34d3ddc0970b74 to 82d8701b2c930d0e96b0dbc9115a218d791cb0d2 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 3.5 is affected
  • unaffected from 0 to 3.5 (excl.)
  • unaffected from 6.1.169 to 6.1.* (incl.)
  • unaffected from 6.6.135 to 6.6.* (incl.)
  • unaffected from 6.12.82 to 6.12.* (incl.)
  • unaffected from 6.18.23 to 6.18.* (incl.)
  • unaffected from 6.19.13 to 6.19.* (incl.)
  • unaffected from 7.0 to * (incl.)

References