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

Message ID 20250317-vsock-trans-signal-race-v4-0-fc8837f3f1d4@rbox.co (mailing list archive)
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Series vsock/bpf: Handle races between sockmap update and connect() disconnecting | expand

Message

Michal Luczaj March 17, 2025, 9:52 a.m. UTC 
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@rbox.co>
---
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@rbox.co

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@rbox.co

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@rbox.co

---
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,