CVE-2026-98347

Description

In the Linux kernel, the following vulnerability has been resolved: IB/IPoIB: Avoid restoring OPER_UP after multicast flush ipoib_ib_dev_flush_light() temporarily clears IPOIB_FLAG_OPER_UP to prevent multicast joins while ipoib_mcast_dev_flush() is running, and restores the flag afterwards if it was previously set. This restore races with ipoib_ib_dev_down(). If the interface is brought down while the flush is in progress, ipoib_ib_dev_down() clears IPOIB_FLAG_OPER_UP, but the flush path may set it again after the device has already gone down. Since commit 894021a75291 ("IB/ipoib: Make the carrier_on_task race aware"), ipoib_mcast_carrier_on_task() relies on IPOIB_FLAG_OPER_UP being cleared to terminate its rtnl_trylock() retry loop. If the flag is left set after shutdown, the workqueue retries forever, causing teardown to deadlock when ipoib_ndo_uninit() waits in destroy_workqueue() while holding RTNL. Instead of overloading IPOIB_FLAG_OPER_UP to block multicast joins during a light flush, introduce a dedicated IPOIB_FLAG_MCAST_FLUSH flag. Use it together with IPOIB_FLAG_OPER_UP to determine whether multicast joins are allowed, avoiding the race with device shutdown.

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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/188b334a6db36a8e0bfaaf59bc4020639a0f3aad https://git.kernel.org/stable/c/1b11e4b55b41d9e69a8e8d07622614202e2eaca9 https://git.kernel.org/stable/c/1ff3add37c329704ec46181b4ae4f00f9f16ce6f https://git.kernel.org/stable/c/326f7d34bd7e64de535566b65c0533b640df5a81 https://git.kernel.org/stable/c/5ad925d45f28464a5e043c9620880bb6a030da89 https://git.kernel.org/stable/c/9a141d3dc869d18b2eab35e999f4790a9b84e40f https://git.kernel.org/stable/c/b72f38929f4b5aa83161fd3b22a7327207e51ec5 https://git.kernel.org/stable/c/f973769fb7cb33ba0d4a64b7dcfee0cabaead938

Frequently Asked Questions

What is CVE-2026-98347? +

In the Linux kernel, the following vulnerability has been resolved: IB/IPoIB: Avoid restoring OPER_UP after multicast flush ipoib_ib_dev_flush_light() temporarily clears IPOIB_FLAG_OPER_UP to prevent multicast joins while ipoib_mcast_dev_flush() is running, and restores the flag afterwards if it was previously set. This restore races with ipoib_ib_dev_down(). If the interface is brought down while the flush is in progress, ipoib_ib_dev_down() clears IPOIB_FLAG_OPER_UP, but the flush path may set it again after the device has already gone down. Since commit 894021a75291 ("IB/ipoib: Make the carrier_on_task race aware"), ipoib_mcast_carrier_on_task() relies on IPOIB_FLAG_OPER_UP being cleared to terminate its rtnl_trylock() retry loop. If the flag is left set after shutdown, the workqueue retries forever, causing teardown to deadlock when ipoib_ndo_uninit() waits in destroy_workqueue() while holding RTNL. Instead of overloading IPOIB_FLAG_OPER_UP to block multicast joins during a light flush, introduce a dedicated IPOIB_FLAG_MCAST_FLUSH flag. Use it together with IPOIB_FLAG_OPER_UP to determine whether multicast joins are allowed, avoiding the race with device shutdown.

How do I check if I'm vulnerable to CVE-2026-98347? +

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.