panic: Unknown syscall 2 error: link should be resolved via Readlink()

Status: fixed on 2019/07/12 01:21
Reported-by: syzbot+51e2dfeb1ddcd7402a8d@syzkaller.appspotmail.com
Fix commit: 6db3f8d54c02 Don't mask errors in createAt loop.
First crash: 2612d, last: 2609d

Sample crash report:
panic: Unknown syscall 2 error: link should be resolved via Readlink()

goroutine 264 [running]:
gvisor.dev/gvisor/pkg/sentry/kernel.(*Task).ExtractErrno(0xc00077d500, 0xe92420, 0xc0000ee7f0, 0x2, 0x109)
	pkg/sentry/kernel/task_syscall.go:446 +0x364
DIAGNOSIS:
retrieving stacks: getting sandbox "ci-gvisor-ptrace-direct-overlay-host-3" stacks: urpc method "debug.Stacks" failed: connection reset by peer

Crashes (16):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/07/08 00:11 https://gvisor.googlesource.com/gvisor master 67f2cefce028 f62e1e85 .config console log report syz ci-gvisor-ptrace-direct-overlay-host
2019/07/08 00:10 https://gvisor.googlesource.com/gvisor master 67f2cefce028 f62e1e85 .config console log report syz ci-gvisor-kvm-direct-sandbox
2019/07/08 00:10 https://gvisor.googlesource.com/gvisor master 67f2cefce028 f62e1e85 .config console log report syz ci-gvisor-main
2019/07/08 00:06 https://gvisor.googlesource.com/gvisor master 67f2cefce028 f62e1e85 .config console log report syz ci-gvisor-kvm-direct-overlay-host-race
2019/07/08 00:05 https://gvisor.googlesource.com/gvisor master 67f2cefce028 f62e1e85 .config console log report syz ci-gvisor-kvm-proxy-overlay-sandbox
2019/07/07 23:54 https://gvisor.googlesource.com/gvisor master 67f2cefce028 f62e1e85 .config console log report syz ci-gvisor-ptrace-proxy-sandbox-race
2019/07/06 23:21 https://gvisor.googlesource.com/gvisor master 67f2cefce028 f62e1e85 .config console log report syz ci-gvisor-kvm-proxy-overlay-sandbox
2019/07/06 23:16 https://gvisor.googlesource.com/gvisor master 67f2cefce028 f62e1e85 .config console log report syz ci-gvisor-ptrace-proxy-sandbox-race
2019/07/06 23:15 https://gvisor.googlesource.com/gvisor master 67f2cefce028 f62e1e85 .config console log report syz ci-gvisor-ptrace-direct-overlay-host
2019/07/06 23:15 https://gvisor.googlesource.com/gvisor master 67f2cefce028 f62e1e85 .config console log report syz ci-gvisor-kvm-direct-sandbox
2019/07/06 23:15 https://gvisor.googlesource.com/gvisor master 67f2cefce028 f62e1e85 .config console log report syz ci-gvisor-main
2019/07/06 23:03 https://gvisor.googlesource.com/gvisor master 67f2cefce028 f62e1e85 .config console log report syz ci-gvisor-kvm-direct-overlay-host-race
2019/07/04 14:54 https://gvisor.googlesource.com/gvisor master 9f2f9f0cab7a 55565fa0 .config console log report syz ci-gvisor-main
2019/07/07 23:38 https://gvisor.googlesource.com/gvisor master 67f2cefce028 f62e1e85 .config console log report ci-gvisor-ptrace-proxy-sandbox-race
2019/07/06 22:44 https://gvisor.googlesource.com/gvisor master 67f2cefce028 f62e1e85 .config console log report ci-gvisor-kvm-direct-overlay-host-race
2019/07/04 14:43 https://gvisor.googlesource.com/gvisor master 9f2f9f0cab7a 55565fa0 .config console log report ci-gvisor-main
* Struck through repros no longer work on HEAD.