In the Linux kernel, the following vulnerability has been resolved:
tty: skip cdev_del() when no cdev is registered
TTY device registration can fail before a cdev is allocated.
Serial core keeps the port so setserial can still use it, and later
removal passes the NULL cdev slot to cdev_del(), causing a NULL-pointer
dereference.
Only delete the cdev when the slot is not NULL.
References 3
https://git.kernel.org/stable/c/3dbf85ef40b6366ba15e882f7536cdc98bea579a
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/c3b5623fd97648f2747444aa8932ae604662df93
416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/2af4c46b429907edc8cb069c78fca1d950120b98
416baaa9-dc9f-4396-8d5f-8c081fb06d67