This is a note to let you know that I've just added the patch titled
net/x25: prevent a couple of overflows
to the 5.9-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:
net-x25-prevent-a-couple-of-overflows.patch
and it can be found in the queue-5.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Sun Dec 6 10:19:03 AM CET 2020
From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Date: Tue, 1 Dec 2020 18:15:12 +0300
Subject: net/x25: prevent a couple of overflows
From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
[ Upstream commit 6ee50c8e262a0f0693dad264c3c99e30e6442a56 ]
The .x25_addr[] address comes from the user and is not necessarily
NUL terminated. This leads to a couple problems. The first problem is
that the strlen() in x25_bind() can read beyond the end of the buffer.
The second problem is more subtle and could result in memory corruption.
The call tree is:
x25_connect()
--> x25_write_internal()
--> x25_addr_aton()
The .x25_addr[] buffers are copied to the "addresses" buffer from
x25_write_internal() so it will lead to stack corruption.
Verify that the strings are NUL terminated and return -EINVAL if they
are not.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Fixes: a9288525d2ae ("X25: Dont let x25_bind use addresses containing characters")
Reported-by: "kiyin(尹亮)" <kiyin@xxxxxxxxxxx>
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Acked-by: Martin Schiller <ms@xxxxxxxxxx>
Link: https://lore.kernel.org/r/X8ZeAKm8FnFpN//B@mwanda
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/x25/af_x25.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/net/x25/af_x25.c
+++ b/net/x25/af_x25.c
@@ -681,7 +681,8 @@ static int x25_bind(struct socket *sock,
int len, i, rc = 0;
if (addr_len != sizeof(struct sockaddr_x25) ||
- addr->sx25_family != AF_X25) {
+ addr->sx25_family != AF_X25 ||
+ strnlen(addr->sx25_addr.x25_addr, X25_ADDR_LEN) == X25_ADDR_LEN) {
rc = -EINVAL;
goto out;
}
@@ -775,7 +776,8 @@ static int x25_connect(struct socket *so
rc = -EINVAL;
if (addr_len != sizeof(struct sockaddr_x25) ||
- addr->sx25_family != AF_X25)
+ addr->sx25_family != AF_X25 ||
+ strnlen(addr->sx25_addr.x25_addr, X25_ADDR_LEN) == X25_ADDR_LEN)
goto out;
rc = -ENETUNREACH;
Patches currently in stable-queue which might be from dan.carpenter@xxxxxxxxxx are
queue-5.9/net-x25-prevent-a-couple-of-overflows.patch
queue-5.9/chelsio-chtls-fix-a-double-free-in-chtls_setkey.patch
