-stable review patch. If anyone has any objections, please let us know. --------------------- From: Satyam Sharma We presently use lock_sock() to acquire a lock on a socket in hci_sock_dev_event(), but this goes BUG because lock_sock() can sleep and we're already holding a read-write spinlock at that point. So, we must use the non-sleeping BH version, bh_lock_sock(). However, hci_sock_dev_event() is called from user context and hence using simply bh_lock_sock() will deadlock against a concurrent softirq that tries to acquire a lock on the same socket. Hence, disabling BH's before acquiring the socket lock and enable them afterwards, is the proper solution to fix socket locking in hci_sock_dev_event(). Signed-off-by: Satyam Sharma Signed-off-by: Marcel Holtmann Signed-off-by: Jiri Kosina Signed-off-by: David S. Miller Signed-off-by: Chris Wright Signed-off-by: Greg Kroah-Hartman --- net/bluetooth/hci_sock.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- linux-2.6.21.4.orig/net/bluetooth/hci_sock.c +++ linux-2.6.21.4/net/bluetooth/hci_sock.c @@ -656,7 +656,8 @@ static int hci_sock_dev_event(struct not /* Detach sockets from device */ read_lock(&hci_sk_list.lock); sk_for_each(sk, node, &hci_sk_list.head) { - lock_sock(sk); + local_bh_disable(); + bh_lock_sock_nested(sk); if (hci_pi(sk)->hdev == hdev) { hci_pi(sk)->hdev = NULL; sk->sk_err = EPIPE; @@ -665,7 +666,8 @@ static int hci_sock_dev_event(struct not hci_dev_put(hdev); } - release_sock(sk); + bh_unlock_sock(sk); + local_bh_enable(); } read_unlock(&hci_sk_list.lock); } -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/