linux/drivers/net
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
..
appletalk
arcnet
bonding bonding: add ip checks when store ip target 2013-11-15 17:44:43 -05:00
caif virtio: use size-based config accessors. 2013-10-17 10:55:37 +10:30
can Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-11-13 17:40:34 +09:00
cris
dsa
ethernet Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-11-19 15:50:47 -08:00
fddi net:drivers/net: Miscellaneous conversions to ETH_ALEN 2013-10-02 17:04:45 -04:00
hamradio Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-10-23 16:49:34 -04:00
hippi
hyperv
ieee802154 tree-wide: use reinit_completion instead of INIT_COMPLETION 2013-11-15 09:32:21 +09:00
irda Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2013-11-15 16:47:22 -08:00
phy Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-11-13 17:40:34 +09:00
plip net:drivers/net: Miscellaneous conversions to ETH_ALEN 2013-10-02 17:04:45 -04:00
ppp net: rework recvmsg handler msg_name and msg_namelen logic 2013-11-20 21:52:30 -05:00
slip slip/slcan: added locking in wakeup function 2013-09-20 15:38:26 -04:00
team Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-11-19 15:50:47 -08:00
usb r8152: fix incorrect type in assignment 2013-11-20 15:09:42 -05:00
vmxnet3 vmxnet3: Remove extern from function prototypes 2013-09-24 16:37:10 -07:00
wan Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-11-04 13:48:30 -05:00
wimax wimax: Remove extern from function prototypes 2013-09-24 16:46:22 -07:00
wireless Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-11-19 15:50:47 -08:00
xen-netback Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-11-04 13:48:30 -05:00
dummy.c net: Explicitly initialize u64_stats_sync structures for lockdep 2013-11-06 12:40:25 +01:00
eql.c
ifb.c net: Explicitly initialize u64_stats_sync structures for lockdep 2013-11-06 12:40:25 +01:00
Kconfig
LICENSE.SRC
loopback.c net: Explicitly initialize u64_stats_sync structures for lockdep 2013-11-06 12:40:25 +01:00
macvlan.c Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-14 16:30:30 +09:00
macvtap.c macvtap: limit head length of skb allocated 2013-11-14 16:05:27 -05:00
Makefile
mdio.c
mii.c
netconsole.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-11-04 13:48:30 -05:00
nlmon.c net: Explicitly initialize u64_stats_sync structures for lockdep 2013-11-06 12:40:25 +01:00
ntb_netdev.c
rionet.c
sb1000.c
Space.c net/ethernet: Drop H8/300 Ethernet driver 2013-09-16 18:20:24 -07:00
sungem_phy.c
tun.c tuntap: limit head length of skb allocated 2013-11-14 16:05:27 -05:00
veth.c Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-14 16:30:30 +09:00
virtio_net.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-11-19 15:50:47 -08:00
vxlan.c Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-14 16:30:30 +09:00
xen-netfront.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-11-19 15:50:47 -08:00