diff options
| author | Dan Carpenter <dan.carpenter@oracle.com> | 2020-12-01 18:15:12 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2020-12-02 17:26:36 -0800 |
| commit | 6ee50c8e262a0f0693dad264c3c99e30e6442a56 (patch) | |
| tree | f4c7d9a7f7cf6314c4bce4ba346cd5f91ff95000 /net | |
| parent | 07500a6085806d97039ebcba8d9b8b29129f0106 (diff) | |
| download | linux-6ee50c8e262a0f0693dad264c3c99e30e6442a56.tar.bz2 | |
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>
Diffstat (limited to 'net')
| -rw-r--r-- | net/x25/af_x25.c | 6 |
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; |