linux_dsm_epyc7002/net/core
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
..
datagram.c net, datagram: fix the incorrect comment in zerocopy_sg_from_iovec() 2013-10-29 00:19:04 -04:00
dev_addr_lists.c net, mc: fix the incorrect comments in two mc-related functions 2013-10-29 00:19:05 -04:00
dev_ioctl.c net: fix kernel deadlock with interface rename and netdev name retrieval. 2013-06-26 13:42:54 -07:00
dev.c net: core: Always propagate flag changes to interfaces 2013-11-20 15:29:56 -05:00
drop_monitor.c genetlink: make multicast groups const, prevent abuse 2013-11-19 16:39:06 -05:00
dst.c net: pass info struct via netdevice notifier 2013-05-28 13:11:01 -07:00
ethtool.c net: Add layer 2 hardware acceleration operations for macvlan devices 2013-11-07 19:11:41 -05:00
fib_rules.c net: Fix "ip rule delete table 256" 2013-11-08 14:53:10 -05:00
filter.c net: fix unsafe set_memory_rw from softirq 2013-10-07 15:16:45 -04:00
flow_dissector.c net: flow_dissector: small optimizations in IPv4 dissect 2013-11-08 13:30:02 -05:00
flow.c net: delete __cpuinit usage from all net files 2013-07-14 19:36:58 -04:00
gen_estimator.c net_sched: add 64bit rate estimators 2013-06-11 02:51:03 -07:00
gen_stats.c net_sched: add 64bit rate estimators 2013-06-11 02:51:03 -07:00
iovec.c net: rework recvmsg handler msg_name and msg_namelen logic 2013-11-20 21:52:30 -05:00
link_watch.c net: make all team port device link events urgent 2013-06-13 02:31:41 -07:00
Makefile net: move procfs code to net/core/net-procfs.c 2013-02-19 00:51:10 -05:00
neighbour.c net: neighbour: use source address of last enqueued packet for solicitation 2013-09-26 13:46:10 -04:00
net_namespace.c userns: Kill nsown_capable it makes the wrong thing easy 2013-08-30 23:44:11 -07:00
net-procfs.c rps: selective flow shedding during softnet overflow 2013-05-20 13:48:04 -07:00
net-sysfs.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-11-13 17:40:34 +09:00
net-sysfs.h xps: Add CONFIG_XPS 2010-11-28 18:24:14 -08:00
net-traces.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
netevent.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
netpoll.c netpoll: fix rx_hook() interface by passing the skb 2013-10-25 19:26:58 -04:00
netprio_cgroup.c cgroup: netprio: remove unnecessary task_netprioidx 2013-10-08 16:27:34 -04:00
pktgen.c pktgen: add needed include file 2013-07-29 00:47:14 -07:00
request_sock.c tcp: fix a panic on UP machines in reqsk_fastopen_remove 2013-01-14 18:10:05 -05:00
rtnetlink.c net: fix rtnl notification in atomic context 2013-10-25 19:03:45 -04:00
scm.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2013-09-07 14:35:32 -07:00
secure_seq.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-10-23 16:49:34 -04:00
skbuff.c netfilter: push reasm skb through instead of original frag skbs 2013-11-11 00:19:35 -05:00
sock_diag.c sock_diag: fix filter code sent to userspace 2013-06-10 22:23:32 -07:00
sock.c net: remove function sk_reset_txq() 2013-10-22 14:00:21 -04:00
stream.c net: add sk_stream_is_writeable() helper 2013-07-24 17:54:48 -07:00
sysctl_net_core.c qdisc: allow setting default queuing discipline 2013-08-31 00:32:32 -04:00
timestamping.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
user_dma.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
utils.c net: make net_get_random_once irq safe 2013-10-25 19:03:39 -04:00