Re: [PATCH net v4 0/3] vsock/bpf: Handle races between sockmap update and connect() disconnecting

[Michael S. Tsirkin]

On Mon, Mar 17, 2025 at 10:52:22AM +0100, Michal Luczaj wrote:
> Signal delivery during connect() may disconnect an already established
> socket. Problem is that such socket might have been placed in a sockmap
> before the connection was closed.
> 
> PATCH 1 ensures this race won't lead to an unconnected vsock staying in the
> sockmap. PATCH 2 selftests it. 
> 
> PATCH 3 fixes a related race. Note that selftest in PATCH 2 does test this
> code as well, but winning this race variant may take more than 2 seconds,
> so I'm not advertising it.
> 
> Signed-off-by: Michal Luczaj <mhal@xxxxxxx>

vsock things:

Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>

> ---
> Changes in v4:
> - Selftest: send signal to only our own process
> - Link to v3: https://lore.kernel.org/r/20250316-vsock-trans-signal-race-v3-0-17a6862277c9@xxxxxxx
> 
> Changes in v3:
> - Selftest: drop unnecessary variable initialization and reorder the calls
> - Link to v2: https://lore.kernel.org/r/20250314-vsock-trans-signal-race-v2-0-421a41f60f42@xxxxxxx
> 
> Changes in v2:
> - Handle one more path of tripping the warning
> - Add a selftest
> - Collect R-b [Stefano]
> - Link to v1: https://lore.kernel.org/r/20250307-vsock-trans-signal-race-v1-1-3aca3f771fbd@xxxxxxx
> 
> ---
> Michal Luczaj (3):
>       vsock/bpf: Fix EINTR connect() racing sockmap update
>       selftest/bpf: Add test for AF_VSOCK connect() racing sockmap update
>       vsock/bpf: Fix bpf recvmsg() racing transport reassignment
> 
>  net/vmw_vsock/af_vsock.c                           | 10 ++-
>  net/vmw_vsock/vsock_bpf.c                          | 24 ++++--
>  .../selftests/bpf/prog_tests/sockmap_basic.c       | 99 ++++++++++++++++++++++
>  3 files changed, 124 insertions(+), 9 deletions(-)
> ---
> base-commit: da9e8efe7ee10e8425dc356a9fc593502c8e3933
> change-id: 20250305-vsock-trans-signal-race-d62f7718d099
> 
> Best regards,
> -- 
> Michal Luczaj <mhal@xxxxxxx>