CVE-2026-72389
Description
In the Linux kernel, the following vulnerability has been resolved: bridge: stp: Fix a potential use-after-free when deleting a bridge The three STP timers are not supposed to be armed while the bridge is administratively down. They are synchronously deactivated when the bridge is put administratively down and the various call sites check for 'IFF_UP' before arming them. This check is missing from br_topology_change_detection() and it is possible to engineer a situation in which the topology change timer is armed while the bridge is administratively down, resulting in a use-after-free [1] when the bridge is deleted. Fix by adding the missing check and for good measures synchronously shutdown the three timers when the bridge is deleted. [1] ODEBUG: free active (active state 0) object: ffff88811662b9b0 object type: timer_list hint: br_topology_change_timer_expired (net/bridge/br_stp_timer.c:120) WARNING: lib/debugobjects.c:629 at debug_print_object+0x1bc/0x450, CPU#9: ip/359
How to fix
- Linux Linuxc86579b0a2d201792bcb59316629f4ba4758cfc8, 297a747f59bff6573196d7236178144d66524e68, 4c40eec06eeac37c58e47a6058eb32901218d5d4, 39283907a25e5caf0f2bd2947f6e56644b01e2b7, b4b3458ef88df4798632619f018791d4344bcd92, 40cbfa3a28e0919469d1b086629bb3ce38a83593, 2a00517db8de4be7df3d483b215c5544fb30a191 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| Linux Linux | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ≤ v < c86579b0a2d201792bcb59316629f4ba4758cfc8, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ≤ v < 297a747f59bff6573196d7236178144d66524e68, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ≤ v < 4c40eec06eeac37c58e47a6058eb32901218d5d4, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ≤ v < 39283907a25e5caf0f2bd2947f6e56644b01e2b7, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ≤ v < b4b3458ef88df4798632619f018791d4344bcd92, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ≤ v < 40cbfa3a28e0919469d1b086629bb3ce38a83593, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 ≤ v < 2a00517db8de4be7df3d483b215c5544fb30a191, 2.6.12 | c86579b0a2d201792bcb59316629f4ba4758cfc8, 297a747f59bff6573196d7236178144d66524e68, 4c40eec06eeac37c58e47a6058eb32901218d5d4, 39283907a25e5caf0f2bd2947f6e56644b01e2b7, b4b3458ef88df4798632619f018791d4344bcd92, 40cbfa3a28e0919469d1b086629bb3ce38a83593, 2a00517db8de4be7df3d483b215c5544fb30a191 |
Check your version
Choose the product and enter the version you run to see whether it falls in the affected range.
Attack Surface Management
See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.