Re: [PATCH RESEND net v5 0/4] vsock/virtio: fix TX credit handling

[Stefano Garzarella <sgarzare@redhat.com>]

On Mon, Jan 19, 2026 at 10:17:34AM -0800, Jakub Kicinski wrote:
>On Fri, 16 Jan 2026 21:15:13 +0100 Stefano Garzarella wrote:
>> Resend with the right cc (sorry, a mistake on my env)
>
>Please don't resend within 24h unless asked to:
>https://www.kernel.org/doc/html/next/process/maintainer-netdev.html#tl-dr

Sorry for that, I'll avoid in the future.

>
>> The original series was posted by Melbin K Mathew <mlbnkm1@gmail.com> till
>> v4: https://lore.kernel.org/netdev/20251217181206.3681159-1-mlbnkm1@gmail.com/
>>
>> Since it's a real issue and the original author seems busy, I'm sending
>> the v5 fixing my comments but keeping the authorship (and restoring mine
>> on patch 2 as reported on v4).
>
>Does not apply to net:
>
>Switched to a new branch 'vsock-virtio-fix-tx-credit-handling'
>Applying: vsock/virtio: fix potential underflow in virtio_transport_get_credit()
>Applying: vsock/test: fix seqpacket message bounds test
>Applying: vsock/virtio: cap TX credit to local buffer size
>Applying: vsock/test: add stream TX credit bounds test
>error: patch failed: tools/testing/vsock/vsock_test.c:2414
>error: tools/testing/vsock/vsock_test.c: patch does not apply
>Patch failed at 0004 vsock/test: add stream TX credit bounds test
>hint: Use 'git am --show-current-patch=diff' to see the failed patch
>hint: When you have resolved this problem, run "git am --continue".
>hint: If you prefer to skip this patch, run "git am --skip" instead.
>hint: To restore the original branch and stop patching, run "git am --abort".
>hint: Disable this message with "git config set advice.mergeConflict false"
>
>Did you generate against net-next or there's some mid-air collision?
>(if the former please share the resolution for the resulting conflict;))

Ooops, a new test landed in net, this should be the resolution:

diff --cc tools/testing/vsock/vsock_test.c
index 668fbe9eb3cc,6933f986ef2a..000000000000
--- a/tools/testing/vsock/vsock_test.c
+++ b/tools/testing/vsock/vsock_test.c
@@@ -2414,11 -2510,11 +2510,16 @@@ static struct test_case test_cases[] =
                 .run_client = test_stream_accepted_setsockopt_client,
                 .run_server = test_stream_accepted_setsockopt_server,
         },
  +      {
  +              .name = "SOCK_STREAM virtio MSG_ZEROCOPY coalescence corruption",
  +              .run_client = test_stream_msgzcopy_mangle_client,
  +              .run_server = test_stream_msgzcopy_mangle_server,
  +      },
+       {
+               .name = "SOCK_STREAM TX credit bounds",
+               .run_client = test_stream_tx_credit_bounds_client,
+               .run_server = test_stream_tx_credit_bounds_server,
+       },
         {},
   };


If you prefer I can send a v6. In the mean time I pushed the branch 
here: 
https://github.com/stefano-garzarella/linux/tree/vsock_virtio_fix_tx_credit

Thanks,
Stefano