CVE-2021-47041CVE-2021-47041

In the Linux kernel, the following vulnerability has been resolved: nvmet-tcp: fix incorrect locking in state_change sk callback We are not changing anything in the TCP connection state so we should not take a write_lock but rather a read lock. This caused a deadlock when running nvmet-tcp and nvme-tcp on the same system, where state_change callbacks on the host and on the controller side have causal relationship and made lockdep report on this with blktests: ================================ WARNING: inconsistent lock state 5.12.0-rc3 #1 Tainted: G I -------------------------------- inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-R} usage. nvme/1324 [HC0[0]:SC0[0]:HE1:SE1] takes: ffff888363151000 (clock-AF_INET){++-?}-{2:2}, at: nvme_tcp_state_change+0x21/0x150 [nvme_tcp] {IN-SOFTIRQ-W} state was registered at: __lock_acquire+0x79b/0x18d0 lock_acquire+0x1ca/0x480 _raw_write_lock_bh+0x39/0x80 nvmet_tcp_state_change+0x21/0x170 [nvmet_tcp] tcp_fin+0x2a8/0x780 tcp_data_