From cddf9fc70b06ca47d6ae88de4d86146f61dd1390 Mon Sep 17 00:00:00 2001 From: Gavrilov Ilia Date: Thu, 7 Mar 2024 14:23:50 +0000 Subject: [PATCH] net: kcm: fix incorrect parameter validation in the kcm_getsockopt) function [ Upstream commit 3ed5f415133f9b7518fbe55ba9ae9a3f5e700929 ] 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: ab7ac4eb9832 ("kcm: Kernel Connection Multiplexor module") Signed-off-by: Gavrilov Ilia Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/kcm/kcmsock.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/kcm/kcmsock.c b/net/kcm/kcmsock.c index 083376ea237e..41d892bf12cc 100644 --- a/net/kcm/kcmsock.c +++ b/net/kcm/kcmsock.c @@ -1152,10 +1152,11 @@ static int kcm_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)); + switch (optname) { case KCM_RECV_DISABLE: val = kcm->rx_disabled;