This is a note to let you know that I've just added the patch titled
tcp: fix incorrect parameter validation in the do_tcp_getsockopt() function
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tcp-fix-incorrect-parameter-validation-in-the-do_tcp.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 773631d12ffc8a1c6ae9bf89f7529f34f82fe70c
Author: Gavrilov Ilia <Ilia.Gavrilov@xxxxxxxxxxx>
Date: Thu Mar 7 14:23:49 2024 +0000
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 <Ilia.Gavrilov@xxxxxxxxxxx>
Reviewed-by: Jason Xing <kerneljasonxing@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 712186336997b..3df973d22295c 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3369,11 +3369,11 @@ 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;
