@@ -315,10 +315,7 @@ static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock,
*/
delta = msg->sg.size;
psock->eval = sk_psock_msg_verdict(sk, psock, msg);
- if (msg->sg.size < delta)
- delta -= msg->sg.size;
- else
- delta = 0;
+ delta -= msg->sg.size;
}
if (msg->cork_bytes &&
@@ -809,10 +809,7 @@ static int bpf_exec_tx_verdict(struct sk_msg *msg, struct sock *sk,
if (psock->eval == __SK_NONE) {
delta = msg->sg.size;
psock->eval = sk_psock_msg_verdict(sk, psock, msg);
- if (delta < msg->sg.size)
- delta -= msg->sg.size;
- else
- delta = 0;
+ delta -= msg->sg.size;
}
if (msg->cork_bytes && msg->cork_bytes > msg->sg.size &&
!enospc && !full_record) {
When user returns SK_DROP we need to reset the number of copied bytes to indicate to the user the bytes were dropped and not sent. If we don't reset the copied arg sendmsg will return as if those bytes were copied giving the user a positive return value. This works as expected today except in the case where the user also pops bytes. In the pop case the sg.size is reduced but we don't correctly account for this when copied bytes is reset. The popped bytes are not accounted for and we return a small positive value potentially confusing the user. The reason this happens is due to a typo where we do the wrong comparison when accounting for pop bytes. In this fix notice the if/else is not needed and that we have a similar problem if we push data except its not visible to the user because if delta is larger the sg.size we return a negative value so it appears as an error regardless. Cc: stable@vger.kernel.org Fixes: 7246d8ed4dcce ("bpf: helper to pop data from messages") Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com> Signed-off-by: John Fastabend <john.fastabend@gmail.com> --- net/ipv4/tcp_bpf.c | 5 +---- net/tls/tls_sw.c | 5 +---- 2 files changed, 2 insertions(+), 8 deletions(-)