From: Andrei Emeltchenko <andrei.emeltchenko@xxxxxxxxx> Yet another version of patches fixing kernel crash in RFCOMM / L2CAP. *v4: taken Gustavo comments about timer HZ -> HZ/5 Do not delete l2cap channel and socket sk when sk is owned by user. To delete l2cap channel standard timer is used. lock_sock and release_sock do not hold a normal spinlock directly but instead hold the owner field. This means bh_lock_sock can still execute even if the socket is "locked". More info can be found here: http://www.linuxfoundation.org/collaborate/workgroups/networking/socketlocks When sending following sequence: ... No. Time Source Destination Protocol Info 89 1.951202 RFCOMM Rcvd DISC DLCI=20 90 1.951324 RFCOMM Sent UA DLCI=20 91 1.959381 HCI_EVT Number of Completed Packets 92 1.966461 RFCOMM Rcvd DISC DLCI=0 93 1.966492 L2CAP Rcvd Disconnect Request 94 1.972595 L2CAP Sent Disconnect Response ... krfcommd kernel thread is preempted with l2cap tasklet which remove l2cap_conn (L2CAP connection handler structure). Then rfcomm thread tries to send RFCOMM UA which is reply to RFCOMM DISC and when de-referencing l2cap_conn crash happens. Andrei Emeltchenko (2): Bluetooth: Check sk is not owned before freeing l2cap_conn Bluetooth: timer check sk is not owned before freeing net/bluetooth/l2cap.c | 58 ++++++++++++++++++++++++++++++++++++++---------- 1 files changed, 46 insertions(+), 12 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
