{"id":"CVE-2026-74255","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-74255","summary":"tipc: fix UAF in tipc_l2_send_msg()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: fix UAF in tipc_l2_send_msg()\n\nSyzbot reported a slab-use-after-free in ipvlan_hard_header() when\ncalled from tipc_l2_send_msg().\n\nThe root cause is that tipc_disable_l2_media() calls synchronize_net()\nwhile b->media_ptr is still valid. This allows concurrent RCU readers\nto obtain the device pointer after synchronize_net() has finished.\nThe pointer is cleared later in bearer_disable(), but without any\nsubsequent synchronization, allowing the device to be freed while\nstill in use by readers.\n\nFix this by clearing b->media_ptr in tipc_disable_l2_media() before\ncalling synchronize_net().\n\nThis is safe to do now because the call order in bearer_disable()\nwas reversed in 0d051bf93c06 (\"tipc: make bearer packet filtering generic\")\nto call tipc_node_delete_links() (which needs the pointer) before\ndisable_media().\n\nhttps: //lore.kernel.org/netdev/6a2c1007.428ffe26.258b27.015d.GAE@google.com/T/#u","published":"2026-08-15T05:57:34.293Z","modified":"2026-08-18T03:56:45.091645785Z","cvss":{"score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"5.10.261"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0d8a12d7143126afdf9fbe2e3d438650dd6603ed"},{"type":"WEB","url":"https://git.kernel.org/stable/c/35e0297a93c3c34a3924eeef816c03504e3ab5c5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/50ff092633b06382e5091dd5b093ce943d4ac2f9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/609ced2301be1df7e7ed2ef47d1d916674e6ba3b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/71aafa16d79b107b33837f60b6cbc7d0cb8c5708"},{"type":"WEB","url":"https://git.kernel.org/stable/c/aef12b5ce793dea6b3a97a58fd0f946000ae8945"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f4002f1c669cc02e3763f479fc25ff1dfa9e2420"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f4c3d89fc986b0da196ddfc6cfe0ea5d5d08bec6"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74255.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74255"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-18T03:56:45.091645785Z"}}