android_kernel_samsung_msm8976/net/bluetooth
Hannes Frederic Sowa 2f73d7fde9 net: rework recvmsg handler msg_name and msg_namelen logic
[ 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 <davem@davemloft.net>
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08 07:29:25 -08:00
..
bnep Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-05-01 17:51:54 -07:00
cmtp Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-05-01 17:51:54 -07:00
hidp HID: fix unused rsize usage 2013-10-13 16:08:28 -07:00
rfcomm net: rework recvmsg handler msg_name and msg_namelen logic 2013-12-08 07:29:25 -08:00
a2mp.c Bluetooth: Replaced kzalloc and memcpy with kmemdup 2013-03-18 14:01:50 -03:00
af_bluetooth.c net: rework recvmsg handler msg_name and msg_namelen logic 2013-12-08 07:29:25 -08:00
amp.c Bluetooth: AMP: Use set_bit / test_bit for amp_mgr state 2013-01-09 17:05:05 -02:00
hci_conn.c Bluetooth: introduce hci_conn ref-counting 2013-04-17 02:45:22 -03:00
hci_core.c Bluetooth: Fix rfkill functionality during the HCI setup stage 2013-10-13 16:08:32 -07:00
hci_event.c Bluetooth: Fix encryption key size for peripheral role 2013-10-13 16:08:32 -07:00
hci_sock.c net: rework recvmsg handler msg_name and msg_namelen logic 2013-12-08 07:29:25 -08:00
hci_sysfs.c Bluetooth: Track feature pages in a single table 2013-04-18 00:26:20 -03:00
Kconfig Bluetooth: trivial: Remove newline before EOF 2012-10-24 00:42:47 -02:00
l2cap_core.c Bluetooth: Fix invalid length check in l2cap_information_rsp() 2013-06-23 00:24:58 +01:00
l2cap_sock.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-05-01 17:51:54 -07:00
lib.c bluetooth: Remove unneeded batostr function 2012-09-27 18:10:43 -03:00
Makefile Bluetooth: AMP: Use HCI cmd to Read Loc AMP Assoc 2012-09-27 17:10:32 -03:00
mgmt.c Bluetooth: Fix mgmt handling of power on failures 2013-06-12 10:20:55 -04:00
sco.c net: rework recvmsg handler msg_name and msg_namelen logic 2013-12-08 07:29:25 -08:00
smp.c Bluetooth: Fix checks for LE support on LE-only controllers 2013-06-12 10:20:54 -04:00