Re: [PATCH stable 5.10,5.15 1/2] net: Fix checksum update for ILA adj-transport

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

✅ All tests passed successfully. No issues detected.
No action required from the submitter.

The upstream commit SHA1 provided is correct: 6043b794c7668c19dabc4a93c75b924a19474d59

Status in newer kernel trees:
6.15.y | Present (different SHA1: ce211a9d9fc1)
6.12.y | Present (different SHA1: 0de96086526a)
6.6.y | Present (different SHA1: 5dd8c050f1bc)
6.1.y | Present (different SHA1: 9dc3a16a1abb)
5.15.y | Not found

Note: The patch differs from the upstream commit:
---
1:  6043b794c7668 ! 1:  7f3475830b70a net: Fix checksum update for ILA adj-transport
    @@ Metadata
      ## Commit message ##
         net: Fix checksum update for ILA adj-transport
     
    +    [ Upstream commit 6043b794c7668c19dabc4a93c75b924a19474d59 ]
    +    [ Note: Fixed conflict due to unrelated change in
    +      inet_proto_csum_replace_by_diff. ]
    +
         During ILA address translations, the L4 checksums can be handled in
         different ways. One of them, adj-transport, consist in parsing the
         transport layer and updating any found checksum. This logic relies on
    @@ Commit message
         Acked-by: Daniel Borkmann <daniel@iogearbox.net>
         Link: https://patch.msgid.link/b5539869e3550d46068504feb02d37653d939c0b.1748509484.git.paul.chaignon@gmail.com
         Signed-off-by: Jakub Kicinski <kuba@kernel.org>
    +    Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
     
      ## include/net/checksum.h ##
     @@ include/net/checksum.h: void inet_proto_csum_replace16(__sum16 *sum, struct sk_buff *skb,
    @@ net/core/utils.c: void inet_proto_csum_replace16(__sum16 *sum, struct sk_buff *s
     +				     __wsum diff, bool pseudohdr, bool ipv6)
      {
      	if (skb->ip_summed != CHECKSUM_PARTIAL) {
    - 		csum_replace_by_diff(sum, diff);
    + 		*sum = csum_fold(csum_add(diff, ~csum_unfold(*sum)));
     -		if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
     +		if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr && !ipv6)
    - 			skb->csum = ~csum_sub(diff, skb->csum);
    + 			skb->csum = ~csum_add(diff, ~skb->csum);
      	} else if (pseudohdr) {
      		*sum = ~csum_fold(csum_add(diff, csum_unfold(*sum)));
     
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-5.15.y       |  Success    |  Success   |