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| author | Michael Tuexen <tuexen@FreeBSD.org> | 2021-02-27 22:27:30 +0000 |
|---|---|---|
| committer | Michael Tuexen <tuexen@FreeBSD.org> | 2021-02-27 22:27:30 +0000 |
| commit | 70e95f0b6917a8b8cd4a2a5f883f3e9753fc86d8 (patch) | |
| tree | d03140b07c0532d2a0c51fd8d077eac2ffb9c758 | |
| parent | d656ce199d72f1aeeef1b2e28b4a284c968a8d03 (diff) | |
| download | src-70e95f0b6917a8b8cd4a2a5f883f3e9753fc86d8.tar.gz src-70e95f0b6917a8b8cd4a2a5f883f3e9753fc86d8.zip | |
sctp: avoid integer overflow when starting the HB timer
MFC after: 3 days
Reported by: syzbot+14b9d7c3c64208fae62f@syzkaller.appspotmail.com
| -rw-r--r-- | sys/netinet/sctputil.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/sys/netinet/sctputil.c b/sys/netinet/sctputil.c index 319344842d5f..7ddb4c3710df 100644 --- a/sys/netinet/sctputil.c +++ b/sys/netinet/sctputil.c @@ -2277,14 +2277,19 @@ sctp_timer_start(int t_type, struct sctp_inpcb *inp, struct sctp_tcb *stcb, } rndval = sctp_select_initial_TSN(&inp->sctp_ep); jitter = rndval % to_ticks; - if (jitter >= (to_ticks >> 1)) { - to_ticks = to_ticks + (jitter - (to_ticks >> 1)); + to_ticks >>= 1; + if (jitter < (UINT32_MAX - to_ticks)) { + to_ticks += jitter; } else { - to_ticks = to_ticks - jitter; + to_ticks = UINT32_MAX; } if (!(net->dest_state & SCTP_ADDR_UNCONFIRMED) && !(net->dest_state & SCTP_ADDR_PF)) { - to_ticks += net->heart_beat_delay; + if (net->heart_beat_delay < (UINT32_MAX - to_ticks)) { + to_ticks += net->heart_beat_delay; + } else { + to_ticks = UINT32_MAX; + } } /* * Now we must convert the to_ticks that are now in ms to |