tree 84925b3d7052ed3117939b267024da24d680d00e
parent 797a93647a48d6cb8a20641a86a71713a947f786
author linzhang <xiaolou4617@gmail.com> 1495692438 +0800
committer David S. Miller <davem@davemloft.net> 1495822829 -0400

net: llc: add lock_sock in llc_ui_bind to avoid a race condition

There is a race condition in llc_ui_bind if two or more processes/threads
try to bind a same socket.

If more processes/threads bind a same socket success that will lead to
two problems, one is this action is not what we expected, another is
will lead to kernel in unstable status or oops(in my simple test case,
cause llc2.ko can't unload).

The current code is test SOCK_ZAPPED bit to avoid a process to
bind a same socket twice but that is can't avoid more processes/threads
try to bind a same socket at the same time.

So, add lock_sock in llc_ui_bind like others, such as llc_ui_connect.

Signed-off-by: Lin Zhang <xiaolou4617@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>