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

Bluetooth: hci_{ldisc,serdev}: check percpu_init_rwsem() failure

syzbot is reporting NULL pointer dereference at hci_uart_tty_close() [1],
for rcu_sync_enter() is called without rcu_sync_init() due to
hci_uart_tty_open() ignoring percpu_init_rwsem() failure.

While we are at it, fix that hci_uart_register_device() ignores
percpu_init_rwsem() failure and hci_uart_unregister_device() does not
call percpu_free_rwsem().

References

• https://nvd.nist.gov/vuln/detail/CVE-2022-50374
• https://git.kernel.org/stable/c/3124d320c22f3f4388d9ac5c8f37eaad0cefd6b1
• https://git.kernel.org/stable/c/75b2c71ea581c7bb1303860d89366a42ad0506d2
• https://git.kernel.org/stable/c/98ce10f3f345e61fc6c83bff9cd11cda252b05ac
• https://git.kernel.org/stable/c/b8917dce2134739b39bc0a5648b18427f2cad569
• https://git.kernel.org/stable/c/d7cc0d51ffcbfd1caaa809fcf9cff05c46d0fb4d