The branch main has been updated by tuexen: URL: https://cgit.FreeBSD.org/src/commit/?id=6d9e911fbadf3b409802a211c1dae9b47cb5a2b8
commit 6d9e911fbadf3b409802a211c1dae9b47cb5a2b8 Author: Michael Tuexen <[email protected]> AuthorDate: 2022-09-19 10:42:43 +0000 Commit: Michael Tuexen <[email protected]> CommitDate: 2022-09-19 10:49:31 +0000 tcp: fix computation of offset Only update the offset if actually retransmitting from the scoreboard. If not done correctly, this may result in trying to (re)-transmit data not being being in the socket buffe and therefore resulting in a panic. PR: 264257 PR: 263445 PR: 260393 Reviewed by: rscheff@ MFC after: 3 days Sponsored by: Netflix, Inc. Differential Revision: https://reviews.freebsd.org/D36626 --- sys/netinet/tcp_output.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/sys/netinet/tcp_output.c b/sys/netinet/tcp_output.c index 0630e288c20f..1a8887984b7f 100644 --- a/sys/netinet/tcp_output.c +++ b/sys/netinet/tcp_output.c @@ -338,10 +338,10 @@ again: len = ((int32_t)ulmin(cwin, SEQ_SUB(p->end, p->rxmit))); } - off = SEQ_SUB(p->rxmit, tp->snd_una); - KASSERT(off >= 0,("%s: sack block to the left of una : %d", - __func__, off)); if (len > 0) { + off = SEQ_SUB(p->rxmit, tp->snd_una); + KASSERT(off >= 0,("%s: sack block to the left of una : %d", + __func__, off)); sack_rxmit = 1; sendalot = 1; TCPSTAT_INC(tcps_sack_rexmits);
