CVE-2026-98301

Description

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.

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EPSS — Exploit Prediction

0.0018

Probability of exploitation

0.07%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

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

Frequently Asked Questions

What is CVE-2026-98301? +

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.

How do I check if I'm vulnerable to CVE-2026-98301? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.