Linux kernel: batman-adv use-after-free via RCU release in mcast
CVE-2026-64096 Published on July 19, 2026
batman-adv: mcast: fix use-after-free in orig_node RCU release
In the Linux kernel, the following vulnerability has been resolved:
batman-adv: mcast: fix use-after-free in orig_node RCU release
batadv_mcast_purge_orig() removes entries from RCU-protected hlists but
does not wait for an RCU grace period before returning. Concurrent RCU
readers may still accesses references to those entries at the point of
removal. RCU-protected readers trying to operate on entries like
orig->mcast_want_all_ipv6_node will then access already freed memory.
Fix this by moving batadv_mcast_purge_orig() to batadv_orig_node_release(),
just before the call_rcu() invocation. This ensures RCU readers that were
active at purge time have drained before the orig_node memory is reclaimed.
Products Associated with CVE-2026-64096
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Affected Versions
Linux:- Version ab49886e3da73b6b35ece21006e191910427bb30 and below ff3a4487ead475e27b43280b8ee3d8464fe280e1 is affected.
- Version ab49886e3da73b6b35ece21006e191910427bb30 and below 78a63fb2f7d5630d1c1f2859a20d4e4226863b41 is affected.
- Version ab49886e3da73b6b35ece21006e191910427bb30 and below ced48f55bac73f0822eae90509e51b42b4f646c8 is affected.
- Version ab49886e3da73b6b35ece21006e191910427bb30 and below 70bcb678561f0fb58f33270fc73f12f3be72b878 is affected.
- Version ab49886e3da73b6b35ece21006e191910427bb30 and below aef897c9d2dd0d9339167fb82b62beff68d076cb is affected.
- Version ab49886e3da73b6b35ece21006e191910427bb30 and below 8a3707653ab658e082ccd992e92594e01b09a3fc is affected.
- Version ab49886e3da73b6b35ece21006e191910427bb30 and below edfb1e094104a50f931553dc82ac59246569fd32 is affected.
- Version ab49886e3da73b6b35ece21006e191910427bb30 and below 20c2d6a20ca936f5aaa6dd40f73f262ac45c87cc is affected.
- Version 3.15 is affected.
- Before 3.15 is unaffected.
- Version 5.10.258, <= 5.10.* is unaffected.
- Version 5.15.209, <= 5.15.* is unaffected.
- Version 6.1.175, <= 6.1.* is unaffected.
- Version 6.6.142, <= 6.6.* is unaffected.
- Version 6.12.92, <= 6.12.* is unaffected.
- Version 6.18.34, <= 6.18.* is unaffected.
- Version 7.0.11, <= 7.0.* is unaffected.
- Version 7.1, <= * is unaffected.