linux/net/irda
Hannes Frederic Sowa f3d3342602 net: rework recvmsg handler msg_name and msg_namelen logic
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>
2013-11-20 21:52:30 -05:00
..
ircomm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-05-01 14:08:52 -07:00
irlan net/irda: fixed style issues in irlan_eth 2013-07-16 12:16:03 -07:00
irnet net: misc: Remove extern from function prototypes 2013-10-19 19:12:11 -04:00
af_irda.c net: rework recvmsg handler msg_name and msg_namelen logic 2013-11-20 21:52:30 -05:00
discovery.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
irda_device.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
iriap_event.c
iriap.c irda: small read past the end of array in debug code 2013-04-19 17:32:31 -04:00
irias_object.c
irlap_event.c irda: irlap_event: Fix set-but-unused variables. 2011-04-17 16:59:09 -07:00
irlap_frame.c net: irda: using kzalloc() instead of kmalloc() to avoid strncpy() issue. 2013-05-19 15:10:47 -07:00
irlap.c Fix common misspellings 2011-03-31 11:26:23 -03:00
irlmp_event.c Fix common misspellings 2011-03-31 11:26:23 -03:00
irlmp_frame.c
irlmp.c irda: irlmp_reasons[] can be static 2013-04-25 01:42:06 -04:00
irmod.c
irnetlink.c genetlink: only pass array to genl_register_family_with_ops() 2013-11-19 16:39:05 -05:00
irproc.c irda: irproc: Fix set-but-unused variables. 2011-04-17 16:59:50 -07:00
irqueue.c net: Remove casts to same type 2012-06-04 11:45:11 -04:00
irsysctl.c net: Convert uses of typedef ctl_table to struct ctl_table 2013-06-13 02:36:09 -07:00
irttp.c net/irda: fixed style issues in irttp 2013-07-19 17:34:40 -07:00
Kconfig
Makefile
parameters.c
qos.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
timer.c treewide: Replace incomming with incoming in all comments and strings 2013-01-03 16:15:49 +01:00
wrapper.c