From b42e56435846338ba437bc9e30aa9ae38f5a6e7a 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 [ Upstream commit 955e9876ba4ee26eeaab1b13517f5b2c88e73d55 ] 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 Signed-off-by: Sasha Levin --- 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 5ecc0f200944..b1d89c850f68 100644 --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -1357,11 +1357,11 @@ 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;