From 6a1015b0b4b1f3a0de9e40d2ba86877d13f50918 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Sat, 23 May 2020 20:46:48 +0300 Subject: [PATCH] ipv4: potential underflow in compat_ip_setsockopt() The value of "n" is capped at 0x1ffffff but it checked for negative values. I don't think this causes a problem but I'm not certain and it's harmless to prevent it. Fixes: 2e04172875c9 ("ipv4: do compat setsockopt for MCAST_MSFILTER directly") Signed-off-by: Dan Carpenter Signed-off-by: David S. Miller --- net/ipv4/ip_sockglue.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index a2469bc57cfe..f43d5f12aa86 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -1347,8 +1347,8 @@ int compat_ip_setsockopt(struct sock *sk, int level, int optname, { const int size0 = offsetof(struct compat_group_filter, gf_slist); struct compat_group_filter *gf32; + unsigned int n; void *p; - int n; if (optlen < size0) return -EINVAL;