This is a note to let you know that I've just added the patch titled
tcp: call sk_wmem_schedule before sk_mem_charge in zerocopy path
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:
tcp-call-sk_wmem_schedule-before-sk_mem_charge-in-zerocopy-path.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.
>From 358ed624207012f03318235017ac6fb41f8af592 Mon Sep 17 00:00:00 2001
From: Talal Ahmad <talalahmad@xxxxxxxxxx>
Date: Fri, 9 Jul 2021 11:43:06 -0400
Subject: tcp: call sk_wmem_schedule before sk_mem_charge in zerocopy path
From: Talal Ahmad <talalahmad@xxxxxxxxxx>
commit 358ed624207012f03318235017ac6fb41f8af592 upstream.
sk_wmem_schedule makes sure that sk_forward_alloc has enough
bytes for charging that is going to be done by sk_mem_charge.
In the transmit zerocopy path, there is sk_mem_charge but there was
no call to sk_wmem_schedule. This change adds that call.
Without this call to sk_wmem_schedule, sk_forward_alloc can go
negetive which is a bug because sk_forward_alloc is a per-socket
space that has been forward charged so this can't be negative.
Fixes: f214f915e7db ("tcp: enable MSG_ZEROCOPY")
Signed-off-by: Talal Ahmad <talalahmad@xxxxxxxxxx>
Reviewed-by: Willem de Bruijn <willemb@xxxxxxxxxx>
Reviewed-by: Wei Wang <weiwan@xxxxxxxxxx>
Reviewed-by: Soheil Hassas Yeganeh <soheil@xxxxxxxxxx>
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ipv4/tcp.c | 3 +++
1 file changed, 3 insertions(+)
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1361,6 +1361,9 @@ new_segment:
}
pfrag->offset += copy;
} else {
+ if (!sk_wmem_schedule(sk, copy))
+ goto wait_for_space;
+
err = skb_zerocopy_iter_stream(sk, skb, msg, copy, uarg);
if (err == -EMSGSIZE || err == -EEXIST) {
tcp_mark_push(tp, skb);
Patches currently in stable-queue which might be from talalahmad@xxxxxxxxxx are
queue-5.10/tcp-call-sk_wmem_schedule-before-sk_mem_charge-in-zerocopy-path.patch
