caif: Bugfix list_del_rcu race in cfmuxl_ctrlcmd.
caif: Bugfix list_del_rcu race in cfmuxl_ctrlcmd.

Always use cfmuxl_remove_uplayer when removing a up-layer.
cfmuxl_ctrlcmd() can be called independently and in parallel with
cfmuxl_remove_uplayer(). The race between them could cause list_del_rcu
to be called on a node which has been already taken out from the list.
That lead to a (rare) crash on accessing poisoned node->prev inside
list_del_rcu.

This fix ensures that deletion are done holding the same lock.

Reported-by: Dmitry Tarnyagin <cdbc1503a3f958fe0b2127f997ae9dd9acf27e55@stericsson.com>
Signed-off-by: Sjur Brændeland <90c9f68dc7b20ac89683f2c4f55e4a05e8dbf9ad@stericsson.com>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs