Commit a2ef3128 authored by Andrey Vagin's avatar Andrey Vagin Committed by Greg Kroah-Hartman

net/unix: fix logic about sk_peek_offset

[ Upstream commit e9193d60 ]

Now send with MSG_PEEK can return data from multiple SKBs.

Unfortunately we take into account the peek offset for each skb,
that is wrong. We need to apply the peek offset only once.

In addition, the peek offset should be used only if MSG_PEEK is set.

Cc: "David S. Miller" <davem@davemloft.net> (maintainer:NETWORKING
Cc: Eric Dumazet <edumazet@google.com> (commit_signer:1/14=7%)
Cc: Aaron Conole <aconole@bytheb.org>
Fixes: 9f389e35 ("af_unix: return data from multiple SKBs on recv() with MSG_PEEK flag")
Signed-off-by: default avatarAndrey Vagin <avagin@openvz.org>
Tested-by: default avatarAaron Conole <aconole@bytheb.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 9eea993b
......@@ -1956,6 +1956,11 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
goto out;
}
if (flags & MSG_PEEK)
skip = sk_peek_offset(sk, flags);
else
skip = 0;
do {
int chunk;
struct sk_buff *skb, *last;
......@@ -2002,7 +2007,6 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
break;
}
skip = sk_peek_offset(sk, flags);
while (skip >= unix_skb_len(skb)) {
skip -= unix_skb_len(skb);
last = skb;
......@@ -2064,14 +2068,12 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
if (UNIXCB(skb).fp)
siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp);
if (skip) {
sk_peek_offset_fwd(sk, chunk);
skip -= chunk;
}
if (UNIXCB(skb).fp)
break;
skip = 0;
last = skb;
unix_state_lock(sk);
skb = skb_peek_next(skb, &sk->sk_receive_queue);
......
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