llc: fix data loss when reading from a socket in llc_ui_recvmsg()
commit 239af1970bcb039a1551d2c438d113df0010c149 upstream.
For SOCK_STREAM sockets, if user buffer size (len) is less
than skb size (skb->len), the remaining data from skb
will be lost after calling kfree_skb().
To fix this, move the statement for partial reading
above skb deletion.
Found by InfoTeCS on behalf of Linux Verification Center (linuxtesting.org)
Fixes: 30a584d944
("[LLX]: SOCK_DGRAM interface fixes")
Cc: stable@vger.kernel.org
Signed-off-by: Ilia Gavrilov <Ilia.Gavrilov@infotecs.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
committed by
Greg Kroah-Hartman
parent
6764329675
commit
4cfe30f681
@@ -888,15 +888,15 @@ static int llc_ui_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
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if (sk->sk_type != SOCK_STREAM)
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goto copy_uaddr;
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/* Partial read */
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if (used + offset < skb_len)
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continue;
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if (!(flags & MSG_PEEK)) {
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skb_unlink(skb, &sk->sk_receive_queue);
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kfree_skb(skb);
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*seq = 0;
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}
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/* Partial read */
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if (used + offset < skb_len)
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continue;
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} while (len > 0);
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out:
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