linux-stable/net
Willem de Bruijn 100f6d8e09 net: correct zerocopy refcnt with udp MSG_MORE
TCP zerocopy takes a uarg reference for every skb, plus one for the
tcp_sendmsg_locked datapath temporarily, to avoid reaching refcnt zero
as it builds, sends and frees skbs inside its inner loop.

UDP and RAW zerocopy do not send inside the inner loop so do not need
the extra sock_zerocopy_get + sock_zerocopy_put pair. Commit
52900d22288ed ("udp: elide zerocopy operation in hot path") introduced
extra_uref to pass the initial reference taken in sock_zerocopy_alloc
to the first generated skb.

But, sock_zerocopy_realloc takes this extra reference at the start of
every call. With MSG_MORE, no new skb may be generated to attach the
extra_uref to, so refcnt is incorrectly 2 with only one skb.

Do not take the extra ref if uarg && !tcp, which implies MSG_MORE.
Update extra_uref accordingly.

This conditional assignment triggers a false positive may be used
uninitialized warning, so have to initialize extra_uref at define.

Changes v1->v2: fix typo in Fixes SHA1

Fixes: 52900d2228 ("udp: elide zerocopy operation in hot path")
Reported-by: syzbot <syzkaller@googlegroups.com>
Diagnosed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-30 15:54:04 -07:00
..
6lowpan treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
9p treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
802 treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
8021q Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-05-22 08:28:16 -07:00
appletalk treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
atm treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
ax25 treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
batman-adv This feature/cleanup patchset includes the following patches: 2019-05-09 09:44:17 -07:00
bluetooth treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
bpf treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
bpfilter treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
bridge treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
caif SPDX update for 5.2-rc2, round 1 2019-05-21 12:33:38 -07:00
can treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
ceph treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
core net: correct zerocopy refcnt with udp MSG_MORE 2019-05-30 15:54:04 -07:00
dcb treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
dccp treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
decnet treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 24 2019-05-21 11:52:39 +02:00
dns_resolver treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
dsa net: dsa: tag_8021q: Create a stable binary format 2019-05-30 14:47:14 -07:00
ethernet treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
hsr hsr: fix don't prune the master node from the node_db 2019-05-23 09:29:44 -07:00
ieee802154 treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
ife treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
ipv4 net: correct zerocopy refcnt with udp MSG_MORE 2019-05-30 15:54:04 -07:00
ipv6 net: correct zerocopy refcnt with udp MSG_MORE 2019-05-30 15:54:04 -07:00
iucv treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
kcm treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
key treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
l2tp treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
l3mdev treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
lapb treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
llc llc: fix skb leak in llc_build_and_send_ui_pkt() 2019-05-28 17:25:23 -07:00
mac80211 treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
mac802154 treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
mpls treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
ncsi treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2019-05-23 14:45:36 -07:00
netlabel treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
netlink SPDX update for 5.2-rc2, round 1 2019-05-21 12:33:38 -07:00
netrom treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
nfc treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
nsh treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
openvswitch treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
packet treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
phonet SPDX update for 5.2-rc2, round 1 2019-05-21 12:33:38 -07:00
psample treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
qrtr Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-05-22 08:28:16 -07:00
rds treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
rfkill treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
rose treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
rxrpc treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
sched net: sched: don't use tc_action->order during action dump 2019-05-24 13:27:52 -07:00
sctp treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
smc treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
strparser treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
sunrpc treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
switchdev treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
tipc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-05-22 08:28:16 -07:00
tls net/tls: fix no wakeup on partial reads 2019-05-26 21:47:13 -07:00
unix treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
vmw_vsock SPDX update for 5.2-rc2, round 1 2019-05-21 12:33:38 -07:00
wimax treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
wireless treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
x25 treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
xdp treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
xfrm SPDX update for 5.2-rc2, round 1 2019-05-21 12:33:38 -07:00
compat.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile
socket.c net: fix kernel-doc warnings for socket.c 2019-05-19 10:33:22 -07:00
sysctl_net.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00