Please backport to stable 6.7 the following patch which was merged upstream as

commit fe92f874f09145a6951deacaa4961390238bbe0d Author: Michael Lass bevan@bi-co.net Date:   Wed Jan 31 16:52:20 2024 +0100

net: Fix from address in memcpy_to_iter_csum()

While inlining csum_and_memcpy() into memcpy_to_iter_csum(), the from     address passed to csum_partial_copy_nocheck() was accidentally changed.     This causes a regression in applications using UDP, as for example     OpenAFS, causing loss of datagrams.

Fixes: dc32bff195b4 ("iov_iter, net: Fold in csum_and_memcpy()")     Cc: David Howells dhowells@redhat.com     Cc: stable@vger.kernel.org     Cc: regressions@lists.linux.dev     Signed-off-by: Michael Lass bevan@bi-co.net     Reviewed-by: Jeffrey Altman jaltman@auristor.com     Acked-by: David Howells dhowells@redhat.com     Signed-off-by: David S. Miller davem@davemloft.net

Thank you.

-------- Forwarded Message -------- Subject: [PATCH] net: Fix from address in memcpy_to_iter_csum() Date: Wed, 31 Jan 2024 16:52:20 +0100 From: Michael Lass bevan@bi-co.net To: netdev@vger.kernel.org CC: David Howells dhowells@redhat.com, regressions@lists.linux.dev

While inlining csum_and_memcpy() into memcpy_to_iter_csum(), the from address passed to csum_partial_copy_nocheck() was accidentally changed. This causes a regression in applications using UDP, as for example OpenAFS, causing loss of datagrams.

Fixes: dc32bff195b4 ("iov_iter, net: Fold in csum_and_memcpy()") Cc: David Howells dhowells@redhat.com Cc: stable@vger.kernel.org Cc: regressions@lists.linux.dev Signed-off-by: Michael Lass bevan@bi-co.net --- net/core/datagram.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/datagram.c b/net/core/datagram.c index 103d46fa0eeb..a8b625abe242 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -751,7 +751,7 @@ size_t memcpy_to_iter_csum(void *iter_to, size_t progress, size_t len, void *from, void *priv2) { __wsum *csum = priv2; - __wsum next = csum_partial_copy_nocheck(from, iter_to, len); + __wsum next = csum_partial_copy_nocheck(from + progress, iter_to, len); *csum = csum_block_add(*csum, next, progress); return 0;