From: Peilin Ye yepeilin.cs@gmail.com
stable inclusion from linux-4.19.154 commit 796f0d39dcd58e91994f4f86525d09c9e03de293
--------------------------------
[ Upstream commit c5a8a8498eed1c164afc94f50a939c1a10abf8ad ]
do_ip_vs_set_ctl() is referencing uninitialized stack value when `len` is zero. Fix it.
Reported-by: syzbot+23b5f9e7caf61d9a3898@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?id=46ebfb92a8a812621a001ef04d90dfa459520fe... Suggested-by: Julian Anastasov ja@ssi.bg Signed-off-by: Peilin Ye yepeilin.cs@gmail.com Acked-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 Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- net/netfilter/ipvs/ip_vs_ctl.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c index c339b5e386b7..3ad1de081e3c 100644 --- a/net/netfilter/ipvs/ip_vs_ctl.c +++ b/net/netfilter/ipvs/ip_vs_ctl.c @@ -2393,6 +2393,10 @@ do_ip_vs_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len) /* Set timeout values for (tcp tcpfin udp) */ ret = ip_vs_set_timeout(ipvs, (struct ip_vs_timeout_user *)arg); goto out_unlock; + } else if (!len) { + /* No more commands with len == 0 below */ + ret = -EINVAL; + goto out_unlock; }
usvc_compat = (struct ip_vs_service_user *)arg; @@ -2469,9 +2473,6 @@ do_ip_vs_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len) break; case IP_VS_SO_SET_DELDEST: ret = ip_vs_del_dest(svc, &udest); - break; - default: - ret = -EINVAL; }
out_unlock: