From: Mark Amirkan tpacket_snd() can transmit one or more frames before a later frame fails validation. The failing frame is marked TP_STATUS_WRONG_FORMAT, but its error replaces len_sum, so send() reports failure despite the earlier transmission. Return the completed byte count when it is nonzero, as the allocation failure path already does. Keep TP_STATUS_WRONG_FORMAT on the bad frame so userspace can identify it. In a two-frame TPACKET_V2 test, a valid 60-byte frame followed by an oversized frame sends the first frame but returns -EMSGSIZE. With this change, send() returns 60 and the second frame remains marked TP_STATUS_WRONG_FORMAT. Fixes: 69e3c75f4d54 ("net: TX_RING and packet mmap") Cc: stable@vger.kernel.org Assisted-by: Symbolic Signed-off-by: Mark Amirkan --- net/packet/af_packet.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 76bde7906d..b7e1848b61 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2893,7 +2893,7 @@ static int tpacket_snd(struct packet_sock *po, struct msghdr *msg) continue; } else { status = TP_STATUS_WRONG_FORMAT; - err = tp_len; + err = len_sum ? : tp_len; goto out_status; } } --- base-commit: e6b6078ea1731b05b3b552497b3bce4bf8b014ae change-id: 20260913-b4-send-packet-tx-progress-2b0c8b6b4596 Best regards, -- Mark Amirkan