{"id":"CVE-2026-74255","title":"tipc: fix UAF in tipc_l2_send_msg()","summary":"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_dis…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 282b3a056225b35024246f63feb91d769d714dad < 609ced2301be1df7e7ed2ef47d1d916674e6ba3b","Linux >= 282b3a056225b35024246f63feb91d769d714dad < 71aafa16d79b107b33837f60b6cbc7d0cb8c5708","Linux >= 282b3a056225b35024246f63feb91d769d714dad < f4002f1c669cc02e3763f479fc25ff1dfa9e2420","Linux >= 282b3a056225b35024246f63feb91d769d714dad < 50ff092633b06382e5091dd5b093ce943d4ac2f9","Linux >= 282b3a056225b35024246f63feb91d769d714dad < aef12b5ce793dea6b3a97a58fd0f946000ae8945","Linux >= 282b3a056225b35024246f63feb91d769d714dad < 0d8a12d7143126afdf9fbe2e3d438650dd6603ed","Linux >= 282b3a056225b35024246f63feb91d769d714dad < 35e0297a93c3c34a3924eeef816c03504e3ab5c5","Linux >= 282b3a056225b35024246f63feb91d769d714dad < f4c3d89fc986b0da196ddfc6cfe0ea5d5d08bec6","Linux 4.4"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-10-16T18:51:21.997322Z"},"published":"2026-08-15","updated":"2026-10-16","sourceUpdated":"2026-10-16T18:55:27.929Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-74255","references":[{"url":"https://git.kernel.org/stable/c/609ced2301be1df7e7ed2ef47d1d916674e6ba3b"},{"url":"https://git.kernel.org/stable/c/71aafa16d79b107b33837f60b6cbc7d0cb8c5708"},{"url":"https://git.kernel.org/stable/c/f4002f1c669cc02e3763f479fc25ff1dfa9e2420"},{"url":"https://git.kernel.org/stable/c/50ff092633b06382e5091dd5b093ce943d4ac2f9"},{"url":"https://git.kernel.org/stable/c/aef12b5ce793dea6b3a97a58fd0f946000ae8945"},{"url":"https://git.kernel.org/stable/c/0d8a12d7143126afdf9fbe2e3d438650dd6603ed"},{"url":"https://git.kernel.org/stable/c/35e0297a93c3c34a3924eeef816c03504e3ab5c5"},{"url":"https://git.kernel.org/stable/c/f4c3d89fc986b0da196ddfc6cfe0ea5d5d08bec6"}],"tags":["cve.org"],"epss":0.00734,"epssPercentile":0.53476,"ingestedAt":"2026-10-16T19:46:24.389Z","slug":"CVE-2026-74255","body":"## Overview\n\nIn 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\n\n## Affected\n\n- `Linux >= 282b3a056225b35024246f63feb91d769d714dad < 609ced2301be1df7e7ed2ef47d1d916674e6ba3b`\n- `Linux >= 282b3a056225b35024246f63feb91d769d714dad < 71aafa16d79b107b33837f60b6cbc7d0cb8c5708`\n- `Linux >= 282b3a056225b35024246f63feb91d769d714dad < f4002f1c669cc02e3763f479fc25ff1dfa9e2420`\n- `Linux >= 282b3a056225b35024246f63feb91d769d714dad < 50ff092633b06382e5091dd5b093ce943d4ac2f9`\n- `Linux >= 282b3a056225b35024246f63feb91d769d714dad < aef12b5ce793dea6b3a97a58fd0f946000ae8945`\n- `Linux >= 282b3a056225b35024246f63feb91d769d714dad < 0d8a12d7143126afdf9fbe2e3d438650dd6603ed`\n- `Linux >= 282b3a056225b35024246f63feb91d769d714dad < 35e0297a93c3c34a3924eeef816c03504e3ab5c5`\n- `Linux >= 282b3a056225b35024246f63feb91d769d714dad < f4c3d89fc986b0da196ddfc6cfe0ea5d5d08bec6`\n- `Linux 4.4`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}