The branch stable/13 has been updated by rscheff:
URL:
https://cgit.FreeBSD.org/src/commit/?id=d730ffcd6ad3da47d9a1af00a534a78861280f54
commit d730ffcd6ad3da47d9a1af00a534a78861280f54
Author: Richard Scheffenegger <rsch...@freebsd.org>
AuthorDate: 2022-07-14 00:49:10 +0000
Commit: Richard Scheffenegger <rsch...@freebsd.org>
CommitDate: 2024-01-11 00:38:36 +0000
tcp: Undo the consumption of sequence space by FIN in case of a transient
error.
If an error occurs while processing a TCP segment with some data and the FIN
flag, the back out of the sequence number advance does not take into
account the
increase by 1 due to the FIN flag.
Reviewed By: jch, gnn, #transport, tuexen
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D2970
(cherry picked from commit 66605ff791b12a2c3bb4570379db0e14d29fca4c)
---
sys/netinet/tcp_output.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/sys/netinet/tcp_output.c b/sys/netinet/tcp_output.c
index 3ed4d34fd061..3e1a2320f331 100644
--- a/sys/netinet/tcp_output.c
+++ b/sys/netinet/tcp_output.c
@@ -1684,8 +1684,13 @@ timer:
tp->sackhint.sack_bytes_rexmit -= len;
KASSERT(tp->sackhint.sack_bytes_rexmit >= 0,
("sackhint bytes rtx >= 0"));
- } else
+ KASSERT((flags & TH_FIN) == 0,
+ ("error while FIN with SACK rxmit"));
+ } else {
tp->snd_nxt -= len;
+ if (flags & TH_FIN)
+ tp->snd_nxt--;
+ }
}
SOCKBUF_UNLOCK_ASSERT(&so->so_snd); /* Check gotos. */
switch (error) {
