tipc: fix UAF in tipc_l2_send_msg()

Summary

CVECVE-2026-74255
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-15 06:22:24 UTC
Updated2026-08-15 06:22:24 UTC
DescriptionIn 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

Risk And Classification

EPSS: 0.001760000 probability, percentile 0.074230000 (date 2026-08-15)

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 282b3a056225b35024246f63feb91d769d714dad 609ced2301be1df7e7ed2ef47d1d916674e6ba3b git Not specified
CNA Linux Linux affected 282b3a056225b35024246f63feb91d769d714dad 71aafa16d79b107b33837f60b6cbc7d0cb8c5708 git Not specified
CNA Linux Linux affected 282b3a056225b35024246f63feb91d769d714dad f4002f1c669cc02e3763f479fc25ff1dfa9e2420 git Not specified
CNA Linux Linux affected 282b3a056225b35024246f63feb91d769d714dad 50ff092633b06382e5091dd5b093ce943d4ac2f9 git Not specified
CNA Linux Linux affected 282b3a056225b35024246f63feb91d769d714dad aef12b5ce793dea6b3a97a58fd0f946000ae8945 git Not specified
CNA Linux Linux affected 282b3a056225b35024246f63feb91d769d714dad 0d8a12d7143126afdf9fbe2e3d438650dd6603ed git Not specified
CNA Linux Linux affected 282b3a056225b35024246f63feb91d769d714dad 35e0297a93c3c34a3924eeef816c03504e3ab5c5 git Not specified
CNA Linux Linux affected 282b3a056225b35024246f63feb91d769d714dad f4c3d89fc986b0da196ddfc6cfe0ea5d5d08bec6 git Not specified
CNA Linux Linux affected 4.4 Not specified
CNA Linux Linux unaffected 4.4 semver Not specified
CNA Linux Linux unaffected 5.10.261 5.10.* semver Not specified
CNA Linux Linux unaffected 5.15.212 5.15.* semver Not specified
CNA Linux Linux unaffected 6.1.178 6.1.* semver Not specified
CNA Linux Linux unaffected 6.6.145 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.97 6.12.* semver Not specified
CNA Linux Linux unaffected 6.18.40 6.18.* semver Not specified
CNA Linux Linux unaffected 7.1.5 7.1.* semver Not specified
CNA Linux Linux unaffected 7.2-rc1 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/50ff092633b06382e5091dd5b093ce943d4ac2f9 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/609ced2301be1df7e7ed2ef47d1d916674e6ba3b 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/71aafa16d79b107b33837f60b6cbc7d0cb8c5708 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/aef12b5ce793dea6b3a97a58fd0f946000ae8945 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/f4c3d89fc986b0da196ddfc6cfe0ea5d5d08bec6 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/35e0297a93c3c34a3924eeef816c03504e3ab5c5 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/0d8a12d7143126afdf9fbe2e3d438650dd6603ed 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/f4002f1c669cc02e3763f479fc25ff1dfa9e2420 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
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