WARNING: BUG on pkg/sentry/kernel/timekeeper.go:LINE

Status: fixed on 2026/09/22 04:28
Fix commit: 4842a71e1c64 Timekeeper: Read pausableClock before reading monotonic time.
First crash: 29d, last: 28d

Sample crash report:
W0911 18:19:13.297106       1 log.go:359] WARNING: BUG on pkg/sentry/kernel/timekeeper.go:731

timekeeperTimer.Reset(2ยตs): deadline 113475302525ns <= pausableClock 113475380015ns (monotonic time went backwards)
:
goroutine 1903 [running]:
gvisor.dev/gvisor/pkg/log.Stacks(0x1)
	pkg/log/log.go:319 +0x76
gvisor.dev/gvisor/pkg/log.TracebackAll({0xc000bbc000, 0xaa}, {0x0, 0x0, 0x0})
	pkg/log/log.go:358 +0x45
gvisor.dev/gvisor/pkg/log.reportBugOnce(0x2, {0x2270f47, 0x5a}, {0xc001d15570, 0x3, 0x3})
	pkg/log/bug.go:91 +0x833
gvisor.dev/gvisor/pkg/log.BugTracebackfOnce(...)
	pkg/log/bug.go:160
gvisor.dev/gvisor/pkg/sentry/kernel.(*timekeeperTimer).Reset(0xc0016240a0, 0x7d0)
	pkg/sentry/kernel/timekeeper.go:731 +0x267
gvisor.dev/gvisor/pkg/tcpip/transport/tcp.(*backoffTimer).reinit(...)
	pkg/tcpip/transport/tcp/connect.go:741
gvisor.dev/gvisor/pkg/tcpip/transport/tcp.(*handshake).synSentState(0xc001154e10, 0xc0019c4500)
	pkg/tcpip/transport/tcp/connect.go:312 +0xdd7
gvisor.dev/gvisor/pkg/tcpip/transport/tcp.(*handshake).handleSegment(0xc001154e10, 0xc0019c4500)
	pkg/tcpip/transport/tcp/connect.go:536 +0x159
gvisor.dev/gvisor/pkg/tcpip/transport/tcp.(*handshake).processSegments(0xc001154e10)
	pkg/tcpip/transport/tcp/connect.go:554 +0x85
gvisor.dev/gvisor/pkg/tcpip/transport/tcp.handleConnecting(0xc0008f9508)
	pkg/tcpip/transport/tcp/dispatcher.go:172 +0xed
gvisor.dev/gvisor/pkg/tcpip/transport/tcp.(*processor).start(0xc00123b688, 0xc0010d0318)
	pkg/tcpip/transport/tcp/dispatcher.go:344 +0x29f
created by gvisor.dev/gvisor/pkg/tcpip/transport/tcp.(*dispatcher).startLocked in goroutine 634
	pkg/tcpip/transport/tcp/dispatcher.go:436 +0x6d

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/11 18:19 gvisor 31bc0f921c63 90316b3c .config console log report syz / log C ci-gvisor-ptrace-2-race WARNING: BUG on pkg/sentry/kernel/timekeeper.go:LINE
2026/09/11 18:03 gvisor 31bc0f921c63 90316b3c .config console log report syz / log C ci-gvisor-ptrace-1-race WARNING: BUG on pkg/sentry/kernel/timekeeper.go:LINE
2026/09/12 11:00 gvisor 2a1b93a9d537 70a60e12 .config console log report syz / log C ci-gvisor-arm64-ptrace-1-race WARNING: BUG on pkg/sentry/kernel/timekeeper.go:LINE
2026/09/12 03:06 gvisor 2a1b93a9d537 70a60e12 .config console log report syz / log C ci-gvisor-arm64-systrap-1-race WARNING: BUG on pkg/sentry/kernel/timekeeper.go:LINE
2026/09/11 19:11 gvisor 31bc0f921c63 90316b3c console log report syz / log C ci-gvisor-arm64-ptrace-1 WARNING: BUG on pkg/sentry/kernel/timekeeper.go:LINE
2026/09/11 18:13 gvisor 31bc0f921c63 90316b3c console log report syz / log C ci-gvisor-arm64-systrap-1 WARNING: BUG on pkg/sentry/kernel/timekeeper.go:LINE
2026/09/11 19:48 gvisor 31bc0f921c63 90316b3c .config console log report syz / log ci-gvisor-systrap-1-race WARNING: BUG on pkg/sentry/kernel/timekeeper.go:LINE
2026/09/11 13:33 gvisor 31bc0f921c63 90316b3c .config console log report info ci-gvisor-arm64-systrap-1-race WARNING: BUG on pkg/sentry/kernel/timekeeper.go:LINE
* Struck through repros no longer work on HEAD.