linux/net/rds
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
..
af_rds.c rds: Make rds_sock_lock BH rather than IRQ safe. 2012-01-24 17:03:44 -05:00
bind.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
cong.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
connection.c inet: convert inet_ehash_secret and ipv6_hash_secret to net_get_random_once 2013-10-19 19:45:35 -04:00
ib_cm.c IB/rds: suppress incompatible protocol when version is known 2012-12-26 15:17:37 -08:00
ib_rdma.c net, rds, Replace xlist in net/rds/xlist.h with llist 2011-09-15 15:36:32 -04:00
ib_recv.c IB/rds: Correct ib_api use with gs_dma_address/sg_dma_len 2012-12-26 15:17:37 -08:00
ib_ring.c
ib_send.c
ib_stats.c
ib_sysctl.c net: Convert uses of typedef ctl_table to struct ctl_table 2013-06-13 02:36:09 -07:00
ib.c net: Fix files explicitly needing to include module.h 2011-10-31 19:30:28 -04:00
ib.h net: rds: use this_cpu_* per-cpu helper 2012-11-19 18:59:44 -05:00
info.c rds: remove the second argument of k[un]map_atomic() 2012-03-20 21:48:28 +08:00
info.h
iw_cm.c RDS: use gfp flags from caller in conn_alloc() 2012-03-22 19:29:58 -04:00
iw_rdma.c RDS: Remove some unused iWARP code 2012-01-12 20:05:28 -08:00
iw_recv.c Merge branch 'kmap_atomic' of git://github.com/congwang/linux 2012-03-21 09:40:26 -07:00
iw_ring.c
iw_send.c
iw_stats.c
iw_sysctl.c net: Convert uses of typedef ctl_table to struct ctl_table 2013-06-13 02:36:09 -07:00
iw.c net: Fix files explicitly needing to include module.h 2011-10-31 19:30:28 -04:00
iw.h
Kconfig net/rds: remove depends on CONFIG_EXPERIMENTAL 2013-01-11 11:40:02 -08:00
loop.c RDS: use gfp flags from caller in conn_alloc() 2012-03-22 19:29:58 -04:00
loop.h
Makefile
message.c rds: simplify a warning message 2013-03-04 14:12:07 -05:00
page.c net: Fix (nearly-)kernel-doc comments for various functions 2012-07-10 23:13:45 -07:00
rdma_transport.c net: Fix files explicitly needing to include module.h 2011-10-31 19:30:28 -04:00
rdma_transport.h
rdma.c
rds.h net: misc: Remove extern from function prototypes 2013-10-19 19:12:11 -04:00
recv.c net: rework recvmsg handler msg_name and msg_namelen logic 2013-11-20 21:52:30 -05:00
send.c RDS: fix rds-ping spinlock recursion 2012-10-09 13:57:23 -04:00
stats.c net/rds: zero last byte for strncpy 2013-03-08 00:35:44 -05:00
sysctl.c net: Convert uses of typedef ctl_table to struct ctl_table 2013-06-13 02:36:09 -07:00
tcp_connect.c rds: Don't disable BH on BH context 2012-08-22 22:52:04 -07:00
tcp_listen.c rds: Don't disable BH on BH context 2012-08-22 22:52:04 -07:00
tcp_recv.c rds: Don't disable BH on BH context 2012-08-22 22:52:04 -07:00
tcp_send.c rds: Don't disable BH on BH context 2012-08-22 22:52:04 -07:00
tcp_stats.c net: rds: fix const array syntax 2011-07-01 16:16:19 -07:00
tcp.c net: Fix files explicitly needing to include module.h 2011-10-31 19:30:28 -04:00
tcp.h
threads.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
transport.c