This is a note to let you know that I've just added the patch titled
bpf, sockmap: Fix data loss caused by using apply_bytes on ingress redirect
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bpf-sockmap-fix-data-loss-caused-by-using-apply_byte.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit dbe18f2cbaf35b9d673e7cc28ffa32267384b6d2
Author: Pengcheng Yang <yangpc@xxxxxxxxxx>
Date: Tue Nov 29 18:40:40 2022 +0800
bpf, sockmap: Fix data loss caused by using apply_bytes on ingress redirect
[ Upstream commit 9072931f020bfd907d6d89ee21ff1481cd78b407 ]
Use apply_bytes on ingress redirect, when apply_bytes is less than
the length of msg data, some data may be skipped and lost in
bpf_tcp_ingress().
If there is still data in the scatterlist that has not been consumed,
we cannot move the msg iter.
Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: Pengcheng Yang <yangpc@xxxxxxxxxx>
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Acked-by: Jakub Sitnicki <jakub@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/bpf/1669718441-2654-4-git-send-email-yangpc@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c
index 027f7f9256e1..6a1685461f89 100644
--- a/net/ipv4/tcp_bpf.c
+++ b/net/ipv4/tcp_bpf.c
@@ -125,8 +125,11 @@ static int bpf_tcp_ingress(struct sock *sk, struct sk_psock *psock,
tmp->sg.end = i;
if (apply) {
apply_bytes -= size;
- if (!apply_bytes)
+ if (!apply_bytes) {
+ if (sge->length)
+ sk_msg_iter_var_prev(i);
break;
+ }
}
} while (i != msg->sg.end);
