From b9979cae626fb4538e50f6328c8f4597d3f5e7c1 Mon Sep 17 00:00:00 2001 From: Gavrilov Ilia Date: Thu, 7 Mar 2024 14:23:50 +0000 Subject: [PATCH] udp: fix incorrect parameter validation in the udp_lib_getsockopt() function [ Upstream commit 4bb3ba7b74fceec6f558745b25a43c6521cf5506 ] 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") Reviewed-by: Willem de Bruijn Signed-off-by: Gavrilov Ilia Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv4/udp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index a6f982b2d32a..3b3f94479885 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -2679,11 +2679,11 @@ int udp_lib_getsockopt(struct sock *sk, 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)); + switch (optname) { case UDP_CORK: val = READ_ONCE(up->corkflag);