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

greybus: raw: fix use-after-free if write is called after disconnect

If a user writes to the chardev after disconnect has been called, the
kernel panics with the following trace (with
CONFIG_INIT_ON_FREE_DEFAULT_ON=y):

        BUG: kernel NULL pointer dereference, address: 0000000000000218
         ...
        Call Trace:
         <TASK>
         gb_operation_create_common+0x61/0x180
         gb_operation_create_flags+0x28/0xa0
         gb_operation_sync_timeout+0x6f/0x100
         raw_write+0x7b/0xc7 [gb_raw]
         vfs_write+0xcf/0x420
         ? task_mm_cid_work+0x136/0x220
         ksys_write+0x63/0xe0
         do_syscall_64+0xa4/0x290
         entry_SYSCALL_64_after_hwframe+0x77/0x7f

Disconnect calls gb_connection_destroy, which ends up freeing the
connection object. When gb_operation_sync is called in the write file
operations, its gets a freed connection as parameter and the kernel
panics.

The gb_connection_destroy cannot be moved out of the disconnect
function, as the Greybus subsystem expect all connections belonging to a
bundle to be destroyed when disconnect returns.

To prevent this bug, use a rw lock to synchronize access between write
and disconnect. This guarantees that the write function doesn't try
to use a disconnected connection.

https://git.kernel.org/stable/c/48d6c32bc049abd114e8f0836c0e7d7cbfba7827

https://git.kernel.org/stable/c/84265cbd96b97058ef67e3f8be3933667a000835

[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","programFiles":["drivers/staging/greybus/raw.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","versions":[{"version":"e806c7fb8e9bae87fc23958c3789f2c2f96f54a4","lessThan":"48d6c32bc049abd114e8f0836c0e7d7cbfba7827","versionType":"git","status":"affected"},{"version":"e806c7fb8e9bae87fc23958c3789f2c2f96f54a4","lessThan":"84265cbd96b97058ef67e3f8be3933667a000835","versionType":"git","status":"affected"}]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","programFiles":["drivers/staging/greybus/raw.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","versions":[{"version":"4.9","status":"affected"},{"version":"0","lessThan":"4.9","versionType":"semver","status":"unaffected"},{"version":"7.0.10","lessThanOrEqual":"7.0.*","versionType":"semver","status":"unaffected"},{"version":"7.1","lessThanOrEqual":"*","versionType":"original_commit_for_fix","status":"unaffected"}]}]