[PATCH 4.4 04/23] ipvs: ignore IP_VS_SVC_F_HASHED flag when adding service

Greg Kroah-Hartman
2021-06-08T18:29:11Z

From: Julian Anastasov <ja@ssi.bg>

[ Upstream commit 56e4ee82e850026d71223262c07df7d6af3bd872 ]

syzbot reported memory leak [1] when adding service with
HASHED flag. We should ignore this flag both from sockopt
and netlink provided data, otherwise the service is not
hashed and not visible while releasing resources.

[1]
BUG: memory leak
unreferenced object 0xffff888115227800 (size 512):
comm "syz-executor263", pid 8658, jiffies 4294951882 (age 12.560s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff83977188>] kmalloc include/linux/slab.h:556 [inline]
[<ffffffff83977188>] kzalloc include/linux/slab.h:686 [inline]
[<ffffffff83977188>] ip_vs_add_service+0x598/0x7c0 net/netfilter/ipvs/ip_vs_ctl.c:1343
[<ffffffff8397d770>] do_ip_vs_set_ctl+0x810/0xa40 net/netfilter/ipvs/ip_vs_ctl.c:2570
[<ffffffff838449a8>] nf_setsockopt+0x68/0xa0 net/netfilter/nf_sockopt.c:101
[<ffffffff839ae4e9>] ip_setsockopt+0x259/0x1ff0 net/ipv4/ip_sockglue.c:1435
[<ffffffff839fa03c>] raw_setsockopt+0x18c/0x1b0 net/ipv4/raw.c:857
[<ffffffff83691f20>] __sys_setsockopt+0x1b0/0x360 net/socket.c:2117
[<ffffffff836920f2>] __do_sys_setsockopt net/socket.c:2128 [inline]
[<ffffffff836920f2>] __se_sys_setsockopt net/socket.c:2125 [inline]
[<ffffffff836920f2>] __x64_sys_setsockopt+0x22/0x30 net/socket.c:2125
[<ffffffff84350efa>] do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
[<ffffffff84400068>] entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported-and-tested-by: syzbot+e562383183e4b1766930@syzkaller.appspotmail.com
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/netfilter/ipvs/ip_vs_ctl.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index c7ee962a547b..1adbcdda2158 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -1226,7 +1226,7 @@ ip_vs_add_service(struct netns_ipvs *ipvs, struct ip_vs_service_user_kern *u,
ip_vs_addr_copy(svc->af, &svc->addr, &u->addr);
svc->port = u->port;
svc->fwmark = u->fwmark;
- svc->flags = u->flags;
+ svc->flags = u->flags & ~IP_VS_SVC_F_HASHED;
svc->timeout = u->timeout * HZ;
svc->netmask = u->netmask;
svc->ipvs = ipvs;
--
2.30.2