diff options
| author | Yun Lu <luyun@kylinos.cn> | 2025-07-11 17:32:59 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-07-24 08:56:25 +0200 |
| commit | fa0796cd62c255b4af6dfebdd3572cd8de784967 (patch) | |
| tree | 251a7dadf28523c82f86f11d5f3a231f00fdde31 | |
| parent | 0e9c4b36ad0c60473edae079bf608a8c02c01afc (diff) | |
af_packet: fix the SO_SNDTIMEO constraint not effective on tpacked_snd()
commit c1ba3c0cbdb5e53a8ec5d708e99cd4c497028a13 upstream.
Due to the changes in commit 581073f626e3 ("af_packet: do not call
packet_read_pending() from tpacket_destruct_skb()"), every time
tpacket_destruct_skb() is executed, the skb_completion is marked as
completed. When wait_for_completion_interruptible_timeout() returns
completed, the pending_refcnt has not yet been reduced to zero.
Therefore, when ph is NULL, the wait function may need to be called
multiple times until packet_read_pending() finally returns zero.
We should call sock_sndtimeo() only once, otherwise the SO_SNDTIMEO
constraint could be way off.
Fixes: 581073f626e3 ("af_packet: do not call packet_read_pending() from tpacket_destruct_skb()")
Cc: stable@kernel.org
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yun Lu <luyun@kylinos.cn>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/packet/af_packet.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index f3cecb3e4bcb..52a4ea3dc2ac 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2784,7 +2784,7 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) int len_sum = 0; int status = TP_STATUS_AVAILABLE; int hlen, tlen, copylen = 0; - long timeo = 0; + long timeo; mutex_lock(&po->pg_vec_lock); @@ -2838,6 +2838,7 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !vnet_hdr_sz) size_max = dev->mtu + reserve + VLAN_HLEN; + timeo = sock_sndtimeo(&po->sk, msg->msg_flags & MSG_DONTWAIT); reinit_completion(&po->skb_completion); do { @@ -2845,7 +2846,6 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) TP_STATUS_SEND_REQUEST); if (unlikely(ph == NULL)) { if (need_wait && skb) { - timeo = sock_sndtimeo(&po->sk, msg->msg_flags & MSG_DONTWAIT); timeo = wait_for_completion_interruptible_timeout(&po->skb_completion, timeo); if (timeo <= 0) { err = !timeo ? -ETIMEDOUT : -ERESTARTSYS; |