In the Linux kernel, the following vulnerability has been resolved: net: bridge: mst: move switchdev call outside rcu This is a follow-up of one of sashiko's pre-existing bug reports. br_mst_set_state() calls switchdev_port_attr_set() for nonzero MSTIs while holding rcu_read_lock() which invokes the blocking switchdev notifier chain and may sleep. Nonzero MSTI changes come from netlink with rtnl held. Move the switchdev call before entering the rcu section and assert that rtnl is held. The call cannot be deferred because netlink needs its error and extack. Also DSA reads the old bridge MST state during the callback and checks it. A deferred callback will be late and will see the updated state.
Fix
Microsoft's update · Critical
- Release Notes — azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 · build 6.6.158.1-1
From the 2026-Oct release note of Microsoft's Security Update Guide, revised 2026-10-28.
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 2
- StatusReceived → PublishedNVD modified 2026-10-19 09:17
- First seenunscoredNVD modified 2026-10-19 10:18
Affected (CPE criteria) 0
NVD has not attached CPE configurations yet.
References 6
- https://git.kernel.org/stable/c/18a6fe05fb6e18de29fa90d388bb34044114b3d8
- https://git.kernel.org/stable/c/6b431b63219853eef4054e2f1cb073d2ca2059b4
- https://git.kernel.org/stable/c/abf734d150c61acfdfee102169d0e5d1c482e285
- https://git.kernel.org/stable/c/b9661fd2423fc25e91e0517ecc0b6156ad83e3a8
- https://git.kernel.org/stable/c/c40ed3e884c8dc0350f26484030438ef24208ff1
- https://git.kernel.org/stable/c/d5c4ee1fa4e83a12afc051c831936cd8e006cde3