Description · from the CVE record

In the Linux kernel, the following vulnerability has been resolved: tipc: fix UAF in tipc_l2_send_msg() Syzbot reported a slab-use-after-free in ipvlan_hard_header() when called from tipc_l2_send_msg(). The root cause is that tipc_disable_l2_media() calls synchronize_net() while b->media_ptr is still valid. This allows concurrent RCU readers to obtain the device pointer after synchronize_net() has finished. The pointer is cleared later in bearer_disable(), but without any subsequent synchronization, allowing the device to be freed while still in use by readers. Fix this by clearing b->media_ptr in tipc_disable_l2_media() before calling synchronize_net(). This is safe to do now because the call order in bearer_disable() was reversed in 0d051bf93c06 ("tipc: make bearer packet filtering generic") to call tipc_node_delete_links() (which needs the pointer) before disable_media(). https: //lore.kernel.org/netdev/[email protected]/T/#u

Affected

ProductAffectedFixed inSource
Linux282b3a056225b35024246f63feb91d769d714dad – < 609ced2301be1df7e7ed2ef47d1d916674e6ba3b609ced2301be1df7e7ed2ef47d1d916674e6ba3bCNA
Linux282b3a056225b35024246f63feb91d769d714dad – < 71aafa16d79b107b33837f60b6cbc7d0cb8c570871aafa16d79b107b33837f60b6cbc7d0cb8c5708CNA
Linux282b3a056225b35024246f63feb91d769d714dad – < f4002f1c669cc02e3763f479fc25ff1dfa9e2420f4002f1c669cc02e3763f479fc25ff1dfa9e2420CNA
Linux282b3a056225b35024246f63feb91d769d714dad – < 50ff092633b06382e5091dd5b093ce943d4ac2f950ff092633b06382e5091dd5b093ce943d4ac2f9CNA
Linux282b3a056225b35024246f63feb91d769d714dad – < aef12b5ce793dea6b3a97a58fd0f946000ae8945aef12b5ce793dea6b3a97a58fd0f946000ae8945CNA
Linux282b3a056225b35024246f63feb91d769d714dad – < 0d8a12d7143126afdf9fbe2e3d438650dd6603ed0d8a12d7143126afdf9fbe2e3d438650dd6603edCNA
Linux282b3a056225b35024246f63feb91d769d714dad – < 35e0297a93c3c34a3924eeef816c03504e3ab5c535e0297a93c3c34a3924eeef816c03504e3ab5c5CNA
Linux282b3a056225b35024246f63feb91d769d714dad – < f4c3d89fc986b0da196ddfc6cfe0ea5d5d08bec6f4c3d89fc986b0da196ddfc6cfe0ea5d5d08bec6CNA
Linux4.4–CNA

Scores by source

Linux (CNA)9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

refgit.kernel.org/stable/c/609ced2301be1df7e7ed2ef47d1d916674e6ba3brefgit.kernel.org/stable/c/71aafa16d79b107b33837f60b6cbc7d0cb8c5708refgit.kernel.org/stable/c/f4002f1c669cc02e3763f479fc25ff1dfa9e2420refgit.kernel.org/stable/c/50ff092633b06382e5091dd5b093ce943d4ac2f9refgit.kernel.org/stable/c/aef12b5ce793dea6b3a97a58fd0f946000ae8945refgit.kernel.org/stable/c/0d8a12d7143126afdf9fbe2e3d438650dd6603edrefgit.kernel.org/stable/c/35e0297a93c3c34a3924eeef816c03504e3ab5c5refgit.kernel.org/stable/c/f4c3d89fc986b0da196ddfc6cfe0ea5d5d08bec6