| Message ID | CH3PR10MB683386BD63824096BF86BA9DEF0D2@CH3PR10MB6833.namprd10.prod.outlook.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net] af_unix: Read with MSG_PEEK loops if the first unread byte is OOB | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Clearly marked for net |
| netdev/apply | fail | Patch does not apply to net-0 |
From: Rao Shoaib <rao.shoaib@oracle.com> Date: Fri, 19 Apr 2024 04:46:32 +0000 > Read with MSG_PEEK flag loops if the first byte to read is an OOB byte. > commit 22dd70eb2c3d ("af_unix: Don't peek OOB data without MSG_OOB.") > addresses the loop issue but does not address the issue that no data > beyond OOB byte can be read. > > >>> from socket import * > >>> c1, c2 = socketpair(AF_UNIX, SOCK_STREAM) > >>> c1.send(b'a', MSG_OOB) > 1 > >>> c1.send(b'b') > 1 > >>> c2.recv(1, MSG_PEEK | MSG_DONTWAIT) > b'b' > > Fixes: 314001f0bf92 ("af_unix: Add OOB support") > Signed-off-by: Rao Shoaib <Rao.Shoaib@oracle.com> > --- > net/unix/af_unix.c | 25 ++++++++++++++----------- > 1 file changed, 14 insertions(+), 11 deletions(-) > > diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c > index 9a6ad5974dff..8928f1f496f4 100644 > --- a/net/unix/af_unix.c > +++ b/net/unix/af_unix.c > @@ -2658,19 +2658,20 @@ static struct sk_buff *manage_oob(struct sk_buff *skb, struct sock *sk, > if (skb == u->oob_skb) { > if (copied) { > skb = NULL; > - } else if (sock_flag(sk, SOCK_URGINLINE)) { The patch does not apply cleanly on net.git probably because tab was replaced by spaces ? Could you check your mail client config and repost v2 to make patchwork happy ? https://patchwork.kernel.org/project/netdevbpf/patch/CH3PR10MB683386BD63824096BF86BA9DEF0D2@CH3PR10MB6833.namprd10.prod.outlook.com/ > - if (!(flags & MSG_PEEK)) { > + } else if (!(flags & MSG_PEEK)) { > + if (sock_flag(sk, SOCK_URGINLINE)) { > WRITE_ONCE(u->oob_skb, NULL); > consume_skb(skb); > + } else { > + skb_unlink(skb, &sk->sk_receive_queue); > + WRITE_ONCE(u->oob_skb, NULL); > + if (!WARN_ON_ONCE(skb_unref(skb))) > + kfree_skb(skb); > + skb = skb_peek(&sk->sk_receive_queue); > } > - } else if (flags & MSG_PEEK) { > - skb = NULL; > } else { > - skb_unlink(skb, &sk->sk_receive_queue); > - WRITE_ONCE(u->oob_skb, NULL); > - if (!WARN_ON_ONCE(skb_unref(skb))) > - kfree_skb(skb); > - skb = skb_peek(&sk->sk_receive_queue); > + if (!sock_flag(sk, SOCK_URGINLINE)) This can be `else if` to avoid another nesting here. > + skb = skb_peek_next(skb, &sk->sk_receive_queue); > } > } > } > @@ -2747,9 +2748,11 @@ static int unix_stream_read_generic(struct unix_stream_read_state *state, > #if IS_ENABLED(CONFIG_AF_UNIX_OOB) > if (skb) { > skb = manage_oob(skb, sk, flags, copied); > - if (!skb && copied) { > + if (!skb) { > unix_state_unlock(sk); > - break; > + if (copied || (flags & MSG_PEEK)) > + break; > + goto redo; > } > } > #endif > -- > 2.39.3
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 9a6ad5974dff..8928f1f496f4 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -2658,19 +2658,20 @@ static struct sk_buff *manage_oob(struct sk_buff *skb, struct sock *sk, if (skb == u->oob_skb) { if (copied) { skb = NULL; - } else if (sock_flag(sk, SOCK_URGINLINE)) { - if (!(flags & MSG_PEEK)) { + } else if (!(flags & MSG_PEEK)) { + if (sock_flag(sk, SOCK_URGINLINE)) { WRITE_ONCE(u->oob_skb, NULL); consume_skb(skb); + } else { + skb_unlink(skb, &sk->sk_receive_queue); + WRITE_ONCE(u->oob_skb, NULL); + if (!WARN_ON_ONCE(skb_unref(skb))) + kfree_skb(skb); + skb = skb_peek(&sk->sk_receive_queue); } - } else if (flags & MSG_PEEK) { - skb = NULL; } else { - skb_unlink(skb, &sk->sk_receive_queue); - WRITE_ONCE(u->oob_skb, NULL); - if (!WARN_ON_ONCE(skb_unref(skb))) - kfree_skb(skb); - skb = skb_peek(&sk->sk_receive_queue); + if (!sock_flag(sk, SOCK_URGINLINE)) + skb = skb_peek_next(skb, &sk->sk_receive_queue); } } } @@ -2747,9 +2748,11 @@ static int unix_stream_read_generic(struct unix_stream_read_state *state, #if IS_ENABLED(CONFIG_AF_UNIX_OOB) if (skb) { skb = manage_oob(skb, sk, flags, copied); - if (!skb && copied) { + if (!skb) { unix_state_unlock(sk); - break; + if (copied || (flags & MSG_PEEK)) + break; + goto redo; } } #endif
Read with MSG_PEEK flag loops if the first byte to read is an OOB byte. commit 22dd70eb2c3d ("af_unix: Don't peek OOB data without MSG_OOB.") addresses the loop issue but does not address the issue that no data beyond OOB byte can be read. >>> from socket import * >>> c1, c2 = socketpair(AF_UNIX, SOCK_STREAM) >>> c1.send(b'a', MSG_OOB) 1 >>> c1.send(b'b') 1 >>> c2.recv(1, MSG_PEEK | MSG_DONTWAIT) b'b' Fixes: 314001f0bf92 ("af_unix: Add OOB support") Signed-off-by: Rao Shoaib <Rao.Shoaib@oracle.com> --- net/unix/af_unix.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-)