From 955e9876ba4ee26eeaab1b13517f5b2c88e73d55 Mon Sep 17 00:00:00 2001 From: Gavrilov Ilia Date: Thu, 7 Mar 2024 14:23:50 +0000 Subject: [PATCH] l2tp: fix incorrect parameter validation in the pppol2tp_getsockopt() function The 'len' variable can't be negative when assigned the result of 'min_t' because all 'min_t' parameters are cast to unsigned int, and then the minimum one is chosen. To fix the logic, check 'len' as read from 'optlen', where the types of relevant variables are (signed) int. Fixes: 3557baabf280 ("[L2TP]: PPP over L2TP driver core") Reviewed-by: Tom Parkin Signed-off-by: Gavrilov Ilia Signed-off-by: David S. Miller --- net/l2tp/l2tp_ppp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c index f011af6601c9..6146e4e67bbb 100644 --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -1356,11 +1356,11 @@ static int pppol2tp_getsockopt(struct socket *sock, int level, int optname, if (get_user(len, optlen)) return -EFAULT; - len = min_t(unsigned int, len, sizeof(int)); - if (len < 0) return -EINVAL; + len = min_t(unsigned int, len, sizeof(int)); + err = -ENOTCONN; if (!sk->sk_user_data) goto end;