syzbot


WARNING: lock held when returning to user space! (2)

Status: fixed on 2018/07/09 18:05
Subsystems: net
[Documentation on labels]
Fix commit: 9e5750106630 net/ipv6: fix lock imbalance in ip6_route_del()
First crash: 2264d, last: 2263d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 WARNING: lock held when returning to user space! C 2 508d 644d 0/1 upstream: reported C repro on 2022/10/15 19:00
upstream WARNING: lock held when returning to user space! (3) C 2 2030d 2026d 0/27 closed as dup on 2019/01/02 11:24
upstream WARNING: lock held when returning to user space! block C 40 2282d 2297d 5/27 fixed on 2018/05/08 18:30

Sample crash report:
IPv6: ADDRCONF(NETDEV_UP): team0: link is not ready
8021q: adding VLAN 0 to HW filter on device team0
IPv6: ADDRCONF(NETDEV_CHANGE): team0: link becomes ready

================================================
WARNING: lock held when returning to user space!
4.17.0-rc3+ #37 Not tainted
------------------------------------------------
syz-executor294/4558 is leaving the kernel with locks still held!
1 lock held by syz-executor294/4558:
 #0:         (ptrval) (rcu_read_lock){....}, at: ip6_route_del+0xea/0x13f0 net/ipv6/route.c:3206
BUG: scheduling while atomic: syz-executor294/4558/0x00000002
INFO: lockdep is turned off.
Modules linked in:
Kernel panic - not syncing: scheduling while atomic

CPU: 1 PID: 4558 Comm: syz-executor294 Not tainted 4.17.0-rc3+ #37
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 panic+0x22f/0x4de kernel/panic.c:184
 __schedule_bug.cold.85+0xdf/0xdf kernel/sched/core.c:3290
 schedule_debug kernel/sched/core.c:3307 [inline]
 __schedule+0x139e/0x1e30 kernel/sched/core.c:3412
 schedule+0xef/0x430 kernel/sched/core.c:3549
 exit_to_usermode_loop+0x220/0x310 arch/x86/entry/common.c:152
 prepare_exit_to_usermode+0x32e/0x390 arch/x86/entry/common.c:196
 retint_user+0x8/0x18
RIP: 0033:0x441aa9
RSP: 002b:00007ffff8ab4c08 EFLAGS: 00000213 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000441aa9
RDX: 00000000200001c0 RSI: 000000000000890c RDI: 0000000000000003
RBP: 00000000006cd018 R08: 00007fff0000d4d0 R09: 00007fff0000d4d0
R10: 00007ffff8ba82f4 R11: 0000000000000213 R12: 00000000004027a0
R13: 0000000000402830 R14: 0000000000000000 R15: 0000000000000000
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/05/10 05:56 net-next-old 53a7bdfb2a27 12c7428a .config console log report syz C ci-upstream-net-kasan-gce
2018/05/10 15:35 net-next-old 53a7bdfb2a27 12c7428a .config console log report ci-upstream-net-kasan-gce
2018/05/10 12:08 net-next-old 53a7bdfb2a27 12c7428a .config console log report ci-upstream-net-kasan-gce
2018/05/10 01:17 net-next-old 53a7bdfb2a27 12c7428a .config console log report ci-upstream-net-kasan-gce
2018/05/09 23:09 net-next-old 53a7bdfb2a27 12c7428a .config console log report ci-upstream-net-kasan-gce
2018/05/09 21:20 net-next-old 53a7bdfb2a27 12c7428a .config console log report ci-upstream-net-kasan-gce
2018/05/09 14:01 net-next-old 53a7bdfb2a27 12c7428a .config console log report ci-upstream-net-kasan-gce
2018/05/09 10:57 net-next-old 53a7bdfb2a27 12c7428a .config console log report ci-upstream-net-kasan-gce
2018/05/09 09:05 net-next-old 53a7bdfb2a27 12c7428a .config console log report ci-upstream-net-kasan-gce
* Struck through repros no longer work on HEAD.