CVE-2022-49765

In the Linux kernel, the following vulnerability has been resolved:

net/9p: use a dedicated spinlock for trans_fd

Shamelessly copying the explanation from Tetsuo Handa's suggested patch[1] (slightly reworded): syzbot is reporting inconsistent lock state in p9_req_put()[2], for p9_tag_remove() from p9_req_put() from IRQ context is using spin_lock_irqsave() on "struct p9_client"->lock but trans_fd (not from IRQ context) is using spin_lock().

Since the locks actually protect different things in client.c and in trans_fd.c, just replace trans_fd.c's lock by a new one specific to the transport (client.c's protect the idr for fid/tag allocations, while trans_fd.c's protects its own req list and request status field that acts as the transport's state machine)

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.