commit c518adafa39f37858697ac9309c6cf1805581446 upstream.
There are multiple similar bugs implicitly introduced by the
commit c0cfa2d8a7 ("vsock: add multi-transports support") and
commit 6a2c096210 ("vsock: prevent transport modules unloading").
The bug pattern:
[1] vsock_sock.transport pointer is copied to a local variable,
[2] lock_sock() is called,
[3] the local variable is used.
VSOCK multi-transport support introduced the race condition:
vsock_sock.transport value may change between [1] and [2].
Let's copy vsock_sock.transport pointer to local variables after
the lock_sock() call.
Fixes: c0cfa2d8a7 ("vsock: add multi-transports support")
Signed-off-by: Alexander Popov <alex.popov@linux.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Jorgen Hansen <jhansen@vmware.com>
Link: https://lore.kernel.org/r/20210201084719.2257066-1-alex.popov@linux.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
55d900415b