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authorDan Carpenter <dan.carpenter@oracle.com>2020-12-01 18:15:12 +0300
committerJakub Kicinski <kuba@kernel.org>2020-12-02 17:26:36 -0800
commit6ee50c8e262a0f0693dad264c3c99e30e6442a56 (patch)
treef4c7d9a7f7cf6314c4bce4ba346cd5f91ff95000
parent07500a6085806d97039ebcba8d9b8b29129f0106 (diff)
net/x25: prevent a couple of overflows
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@tencent.com> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Martin Schiller <ms@dev.tdt.de> Link: https://lore.kernel.org/r/X8ZeAKm8FnFpN//B@mwanda Signed-off-by: Jakub Kicinski <kuba@kernel.org>
-rw-r--r--net/x25/af_x25.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c
index a10487e7574c..e65a50192432 100644
--- a/net/x25/af_x25.c
+++ b/net/x25/af_x25.c
@@ -681,7 +681,8 @@ static int x25_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
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 *sock, struct sockaddr *uaddr,
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;