kernel/git/stable/linux.git/net/bluetooth/rfcomm, branch linux-3.12.y

Bluetooth: Avoid use of session socket after the session gets freed

2014-09-17T15:06:50+00:00

commit 32333edb82fb2009980eefc5518100068147ab82 upstream. The commits 08c30aca9e698faddebd34f81e1196295f9dc063 "Bluetooth: Remove RFCOMM session refcnt" and 8ff52f7d04d9cc31f1e81dcf9a2ba6335ed34905 "Bluetooth: Return RFCOMM session ptrs to avoid freed session" allow rfcomm_recv_ua and rfcomm_session_close to delete the session (and free the corresponding socket) and propagate NULL session pointer to the upper callers. Additional fix is required to terminate the loop in rfcomm_process_rx function to avoid use of freed 'sk' memory. The issue is only reproducible with kernel option CONFIG_PAGE_POISONING enabled making freed memory being changed and filled up with fixed char value used to unmask use-after-free issues. Signed-off-by: Vignesh Raman Signed-off-by: Vitaly Kuzmichev Acked-by: Dean Jenkins Signed-off-by: Marcel Holtmann Signed-off-by: Jiri Slaby

Bluetooth: never linger on process exit

2014-09-17T15:06:50+00:00

commit 093facf3634da1b0c2cc7ed106f1983da901bbab upstream. If the current process is exiting, lingering on socket close will make it unkillable, so we should avoid it. Reproducer: #include #include #define BTPROTO_L2CAP 0 #define BTPROTO_SCO 2 #define BTPROTO_RFCOMM 3 int main() { int fd; struct linger ling; fd = socket(PF_BLUETOOTH, SOCK_STREAM, BTPROTO_RFCOMM); //or: fd = socket(PF_BLUETOOTH, SOCK_DGRAM, BTPROTO_L2CAP); //or: fd = socket(PF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_SCO); ling.l_onoff = 1; ling.l_linger = 1000000000; setsockopt(fd, SOL_SOCKET, SO_LINGER, &ling, sizeof(ling)); return 0; } Signed-off-by: Vladimir Davydov Signed-off-by: Marcel Holtmann Signed-off-by: Jiri Slaby

net: rework recvmsg handler msg_name and msg_namelen logic

2013-12-08T15:29:13+00:00

[ Upstream commit f3d3342602f8bcbf37d7c46641cb9bca7618eb1c ] This patch now always passes msg->msg_namelen as 0. recvmsg handlers must set msg_namelen to the proper size <= sizeof(struct sockaddr_storage) to return msg_name to the user. This prevents numerous uninitialized memory leaks we had in the recvmsg handlers and makes it harder for new code to accidentally leak uninitialized memory. Optimize for the case recvfrom is called with NULL as address. We don't need to copy the address at all, so set it to NULL before invoking the recvmsg handler. We can do so, because all the recvmsg handlers must cope with the case a plain read() is called on them. read() also sets msg_name to NULL. Also document these changes in include/linux/net.h as suggested by David Miller. Changes since RFC: Set msg->msg_name = NULL if user specified a NULL in msg_name but had a non-null msg_namelen in verify_iovec/verify_compat_iovec. This doesn't affect sendto as it would bail out earlier while trying to copy-in the address. It also more naturally reflects the logic by the callers of verify_iovec. With this change in place I could remove " if (!uaddr || msg_sys->msg_namelen == 0) msg->msg_name = NULL ". This change does not alter the user visible error logic as we ignore msg_namelen as long as msg_name is NULL. Also remove two unnecessary curly brackets in ___sys_recvmsg and change comments to netdev style. Cc: David Miller Suggested-by: Eric Dumazet Signed-off-by: Hannes Frederic Sowa Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

Bluetooth: don't release the port in rfcomm_dev_state_change()

2013-09-20T19:17:54+00:00

When the dlc is closed, rfcomm_dev_state_change() tries to release the port in the case it cannot get a reference to the tty. However this is racy and not even needed. Infact as Peter Hurley points out: 1. Only consider dlcs that are 'stolen' from a connected socket, ie. reused. Allocated dlcs cannot have been closed prior to port activate and so for these dlcs a tty reference will always be avail in rfcomm_dev_state_change() -- except for the conditions covered by #2b below. 2. If a tty was at some point previously created for this rfcomm, then either (a) the tty reference is still avail, so rfcomm_dev_state_change() will perform a hangup. So nothing to do, or, (b) the tty reference is no longer avail, and the tty_port will be destroyed by the last tty_port_put() in rfcomm_tty_cleanup. Again, no action required. 3. Prior to obtaining the dlc lock in rfcomm_dev_add(), rfcomm_dev_state_change() will not 'see' a rfcomm_dev so nothing to do here. 4. After releasing the dlc lock in rfcomm_dev_add(), rfcomm_dev_state_change() will 'see' an incomplete rfcomm_dev if a tty reference could not be obtained. Again, the best thing to do here is nothing. Any future attempted open() will block on rfcomm_dev_carrier_raised(). The unconnected device will exist until released by ioctl(RFCOMMRELEASEDEV). The patch removes the aforementioned code and uses the tty_port_tty_hangup() helper to hangup the tty. Signed-off-by: Gianluca Anzolin Reviewed-by: Peter Hurley Signed-off-by: Gustavo Padovan

Bluetooth: Purge the dlc->tx_queue to avoid circular dependency

2013-08-21T14:47:08+00:00

In rfcomm_tty_cleanup we purge the dlc->tx_queue which may contain socket buffers referencing the tty_port and thus preventing the tty_port destruction. Signed-off-by: Gianluca Anzolin Reviewed-by: Peter Hurley Signed-off-by: Gustavo Padovan

Bluetooth: Fix the reference counting of tty_port

2013-08-21T14:47:07+00:00

The tty_port can be released in two cases: when we get a HUP in the functions rfcomm_tty_hangup() and rfcomm_dev_state_change(). Or when the user releases the device in rfcomm_release_dev(). In these cases we set the flag RFCOMM_TTY_RELEASED so that no other function can get a reference to the tty_port. The use of !test_and_set_bit(RFCOMM_TTY_RELEASED) ensures that the 'initial' tty_port reference is only dropped once. The rfcomm_dev_del function is removed becase it isn't used anymore. Signed-off-by: Gianluca Anzolin Reviewed-by: Peter Hurley Signed-off-by: Gustavo Padovan

Bluetooth: Implement .activate, .shutdown and .carrier_raised methods

2013-08-21T14:47:07+00:00

Implement .activate, .shutdown and .carrier_raised methods of tty_port to manage the dlc, moving the code from rfcomm_tty_install() and rfcomm_tty_cleanup() functions. At the same time the tty .open()/.close() and .hangup() methods are changed to use the tty_port helpers that properly call the aforementioned tty_port methods. Signed-off-by: Gianluca Anzolin Reviewed-by: Peter Hurley Signed-off-by: Gustavo Padovan

Bluetooth: Move the tty initialization and cleanup out of open/close

2013-08-21T14:47:06+00:00

Move the tty_struct initialization from rfcomm_tty_open() to rfcomm_tty_install() and do the same for the cleanup moving the code from rfcomm_tty_close() to rfcomm_tty_cleanup(). Add also extra error handling in rfcomm_tty_install() because, unlike .open()/.close(), .cleanup() is not called if .install() fails. Signed-off-by: Gianluca Anzolin Reviewed-by: Peter Hurley Signed-off-by: Gustavo Padovan

Bluetooth: Remove the device from the list in the destructor

2013-08-21T14:47:06+00:00

The current code removes the device from the device list in several places. Do it only in the destructor instead and in the error path of rfcomm_add_dev() if the device couldn't be initialized. Signed-off-by: Gianluca Anzolin Reviewed-by: Peter Hurley Signed-off-by: Gustavo Padovan

Bluetooth: Take proper tty_struct references

2013-08-21T14:47:05+00:00

In net/bluetooth/rfcomm/tty.c the struct tty_struct is used without taking references. This may lead to a use-after-free of the rfcomm tty. Fix this by taking references properly, using the tty_port_* helpers when possible. The raw assignments of dev->port.tty in rfcomm_tty_open/close are addressed in the later commit 'rfcomm: Implement .activate, .shutdown and .carrier_raised methods'. Signed-off-by: Gianluca Anzolin Reviewed-by: Peter Hurley Signed-off-by: Gustavo Padovan