From c8059876317a8848c44b974c369d4b3e225d91c5 Mon Sep 17 00:00:00 2001 From: Gavrilov Ilia Date: Thu, 7 Mar 2024 14:23:49 +0000 Subject: [PATCH] tcp: fix incorrect parameter validation in the do_tcp_getsockopt() function [ Upstream commit 716edc9706deb3bb2ff56e2eeb83559cea8f22db ] 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: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Gavrilov Ilia Reviewed-by: Jason Xing Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv4/tcp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index a5c15e2d193f..2e874ec85971 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3742,11 +3742,11 @@ static int do_tcp_getsockopt(struct sock *sk, int level, 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)); + switch (optname) { case TCP_MAXSEG: val = tp->mss_cache;