CVE-2026-63874
In the Linux kernel, the following vulnerability has been resolved:
net: mctp: usb: fix race between urb completion and rx_retry cancellation
It's possible that sequencing between setting ->stopped and cancelling
the rx_retry work (in ndo_stop) could leave us with an urb queued:
T1: ndo_stop T2: rx_retry_work
------------ ----------------
LD: ->stopped => false
ST: ->stopped <= true
usb_kill_urb()
mctp_usb_rx_queue()
usb_submit_urb()
cancel_delayed_work_sync()
That urb completion can then re-schedule rx_retry_work.
Strenghen the sequencing between the stop (preventing another requeue)
and the cancel by updating both atomically under a new rx lock. After
setting ->rx_stopped, and cancelling pending work, we know that the
requeue cannot occur, so all that's left is killing any pending urb.
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Exploitation outlook
- Low exploitation risk0.12% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 2% of all EPSS-scored CVEs.
Advisory coverage (1)
External references
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