syzbot


panic: Decrementing non-positive ref count ADDR, owned by kernel.ProcessGroup

Status: auto-closed as invalid on 2022/06/05 05:48
Reported-by: syzbot+98f11c65940f65856218@syzkaller.appspotmail.com
First crash: 995d, last: 995d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
gvisor panic: Decrementing non-positive ref count ADDR, owned by kernel.ProcessGroup (2) C 3 780d 815d 14/26 fixed on 2022/10/07 23:11

Sample crash report:
panic: Decrementing non-positive ref count 0xc002944300, owned by kernel.ProcessGroup

goroutine 85814 [running]:
panic({0x18f9760, 0xc000fd4de0})
	GOROOT/src/runtime/panic.go:1147 +0x3a8 fp=0xc00133b000 sp=0xc00133af40 pc=0x437d08
gvisor.dev/gvisor/pkg/sentry/kernel.(*ProcessGroupRefs).DecRef(0xc002944300, 0xc00133b088)
	bazel-out/k8-fastbuild-ST-fa7f2b6368d1/bin/pkg/sentry/kernel/process_group_refs.go:125 +0x14c fp=0xc00133b060 sp=0xc00133b000 pc=0xd0d4cc
gvisor.dev/gvisor/pkg/sentry/kernel.(*ProcessGroup).decRefWithParent(0xc002944300, 0xc003384dc0)
	pkg/sentry/kernel/sessions.go:159 +0x145 fp=0xc00133b0b0 sp=0xc00133b060 pc=0xd1ff45
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).exitNotifyLocked(0xc002ab0000, 0x0)
	pkg/sentry/kernel/task_exit.go:669 +0x12a5 fp=0xc00133b200 sp=0xc00133b0b0 pc=0xd40345
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).waitCollectZombieLocked(0xc00206f500, 0xc002ab0000, 0xc00133b828, 0x0)
	pkg/sentry/kernel/task_exit.go:1061 +0xbed fp=0xc00133b2d8 sp=0xc00133b200 pc=0xd4368d
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).waitParentLocked(0xc001f9c840, 0xc00133b828, 0xc00206f500)
	pkg/sentry/kernel/task_exit.go:929 +0x245 fp=0xc00133b3e0 sp=0xc00133b2d8 pc=0xd42365
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).waitOnce(0xc00206f500, 0xc00133b828)
	pkg/sentry/kernel/task_exit.go:896 +0x446 fp=0xc00133b4b8 sp=0xc00133b3e0 pc=0xd42006
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Wait(0xc00206f500, 0xc00133b828)
	pkg/sentry/kernel/task_exit.go:869 +0x2e5 fp=0xc00133b600 sp=0xc00133b4b8 pc=0xd418c5
gvisor.dev/gvisor/pkg/sentry/syscalls/linux.wait4(0xc00206f500, 0xffffffffffffffff, 0x7f83f1d9861c, 0x40000001, 0x0)
	pkg/sentry/syscalls/linux/sys_thread.go:288 +0x288 fp=0xc00133b868 sp=0xc00133b600 pc=0xe7c888
gvisor.dev/gvisor/pkg/sentry/syscalls/linux.Wait4(0x7fba6c61f6f0, {{0xffffffff}, {0x7f83f1d9861c}, {0x40000001}, {0x0}, {0x1ddfc4e1}, {0x3b2}})
	pkg/sentry/syscalls/linux/sys_thread.go:316 +0xca fp=0xc00133b8e0 sp=0xc00133b868 pc=0xe7cd4a
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).executeSyscall(0xc00206f500, 0x7fba6c61f6f0, {{0xffffffff}, {0x7f83f1d9861c}, {0x40000001}, {0x0}, {0x1ddfc4e1}, {0x3b2}})
	pkg/sentry/kernel/task_syscall.go:103 +0x411 fp=0xc00133ba88 sp=0xc00133b8e0 pc=0xd65f51
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallInvoke(0xc00206f500, 0x1, {{0xffffffff}, {0x7f83f1d9861c}, {0x40000001}, {0x0}, {0x1ddfc4e1}, {0x3b2}})
	pkg/sentry/kernel/task_syscall.go:238 +0x8e fp=0xc00133bb18 sp=0xc00133ba88 pc=0xd673ce
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscallEnter(0xc002398d20, 0x1, {{0xffffffff}, {0x7f83f1d9861c}, {0x40000001}, {0x0}, {0x1ddfc4e1}, {0x3b2}})
	pkg/sentry/kernel/task_syscall.go:198 +0xc5 fp=0xc00133bb90 sp=0xc00133bb18 pc=0xd66cc5
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).doSyscall(0xc00206f500)
	pkg/sentry/kernel/task_syscall.go:173 +0x4a7 fp=0xc00133bca0 sp=0xc00133bb90 pc=0xd667e7
gvisor.dev/gvisor/pkg/sentry/kernel.(*runApp).execute(0xc00206f500, 0xc00206f500)
	pkg/sentry/kernel/task_run.go:254 +0x19dc fp=0xc00133beb8 sp=0xc00133bca0 pc=0xd5169c
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).run(0xc00206f500, 0xa87)
	pkg/sentry/kernel/task_run.go:95 +0x2d4 fp=0xc00133bfb0 sp=0xc00133beb8 pc=0xd4f274
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start·dwrap·235()
	pkg/sentry/kernel/task_start.go:339 +0x48 fp=0xc00133bfe0 sp=0xc00133bfb0 pc=0xd63c88
runtime.goexit()
	src/runtime/asm_amd64.s:1581 +0x1 fp=0xc00133bfe8 sp=0xc00133bfe0 pc=0x46e081
created by gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).Start
	pkg/sentry/kernel/task_start.go:339 +0x1d1

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/03/07 05:47 gvisor e3f424c5c51c 7bdd8b2c .config console log report info ci-gvisor-ptrace-3-race-cover panic: Decrementing non-positive ref count ADDR, owned by kernel.ProcessGroup
* Struck through repros no longer work on HEAD.