From f465fb249f3a7ff729193a66c3947caa154e83d9 Mon Sep 17 00:00:00 2001 From: Andrey Vagin Date: Fri, 2 Oct 2015 00:05:36 +0300 Subject: [PATCH] net/unix: fix logic about sk_peek_offset commit e9193d60d363e4dff75ff6d43a48f22be26d59c7 upstream. 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" (maintainer:NETWORKING Cc: Eric Dumazet (commit_signer:1/14=7%) Cc: Aaron Conole Fixes: 9f389e35674f ("af_unix: return data from multiple SKBs on recv() with MSG_PEEK flag") Signed-off-by: Andrey Vagin Tested-by: Aaron Conole Signed-off-by: David S. Miller Signed-off-by: Luis Henriques --- net/unix/af_unix.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 30a705ee0ac86..2ae4a5915aa78 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -1962,6 +1962,11 @@ 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; @@ -2008,7 +2013,6 @@ again: break; } - skip = sk_peek_offset(sk, flags); while (skip >= unix_skb_len(skb)) { skip -= unix_skb_len(skb); last = skb; @@ -2070,14 +2074,12 @@ again: if (UNIXCB(skb).fp) siocb->scm->fp = scm_fp_dup(UNIXCB(skb).fp); - if (skip) { - sk_peek_offset_fwd(sk, chunk); - skip -= chunk; - } + sk_peek_offset_fwd(sk, chunk); if (UNIXCB(skb).fp) break; + skip = 0; last = skb; unix_state_lock(sk); skb = skb_peek_next(skb, &sk->sk_receive_queue); -- 2.47.3