Page MenuHomeFreeBSD

tcp: clear SACK state when scoreboard is forcefully freed
ClosedPublic

Authored by rscheff on Oct 11 2023, 8:02 PM.
Tags
None
Referenced Files
Unknown Object (File)
Tue, Oct 14, 5:11 AM
Unknown Object (File)
Tue, Oct 14, 2:04 AM
Unknown Object (File)
Mon, Oct 13, 1:46 AM
Unknown Object (File)
Mon, Oct 6, 3:30 AM
Unknown Object (File)
Sep 10 2025, 7:24 PM
Unknown Object (File)
Sep 2 2025, 3:39 PM
Unknown Object (File)
Sep 2 2025, 2:14 PM
Unknown Object (File)
Jun 18 2025, 11:36 PM
Subscribers

Details

Summary

When a RTO happens during an on-going SACK loss recovery
episode, the internal summary accounting is not cleared.
This may lead to subsequent errors in calculations
(e.g. IsLost()).

PR: 274406
Reported by: pho

Diff Detail

Repository
rG FreeBSD src repository
Lint
Lint Not Applicable
Unit
Tests Not Applicable

Event Timeline

This revision is now accepted and ready to land.Oct 11 2023, 8:06 PM
sys/netinet/tcp_sack.c
891

Better keep the fields in order like in the struct sackhint definition.

tp->sackhint.delivered_data = 0;
tp->sackhint.sacked_bytes = 0;
tp->sackhint.hole_bytes = 0;
tp->sackhint.lost_bytes = 0;

This change fixes the panic I saw.

rscheff edited the test plan for this revision. (Show Details)
rscheff added inline comments.
sys/netinet/tcp_sack.c
891

I trust gcc to do simple reorders like this for more effective data access. Already committed to fix an ongoing panic.