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Commit 6ee50c8

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Dan Carpenterkuba-moo
Dan Carpenter
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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: a928852 ("X25: Dont let x25_bind use addresses containing characters") Reported-by: "kiyin(尹亮)" <[email protected]> Signed-off-by: Dan Carpenter <[email protected]> Acked-by: Martin Schiller <[email protected]> Link: https://lore.kernel.org/r/X8ZeAKm8FnFpN//B@mwanda Signed-off-by: Jakub Kicinski <[email protected]>
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net/x25/af_x25.c

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Original file line numberDiff line numberDiff line change
@@ -681,7 +681,8 @@ static int x25_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
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int len, i, rc = 0;
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if (addr_len != sizeof(struct sockaddr_x25) ||
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addr->sx25_family != AF_X25) {
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addr->sx25_family != AF_X25 ||
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strnlen(addr->sx25_addr.x25_addr, X25_ADDR_LEN) == X25_ADDR_LEN) {
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rc = -EINVAL;
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goto out;
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}
@@ -775,7 +776,8 @@ static int x25_connect(struct socket *sock, struct sockaddr *uaddr,
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rc = -EINVAL;
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if (addr_len != sizeof(struct sockaddr_x25) ||
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addr->sx25_family != AF_X25)
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addr->sx25_family != AF_X25 ||
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strnlen(addr->sx25_addr.x25_addr, X25_ADDR_LEN) == X25_ADDR_LEN)
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goto out;
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rc = -ENETUNREACH;

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