syzbot


WARNING: locking bug in vtime_task_switch_generic

Status: upstream: reported on 2022/08/08 18:35
Reported-by: syzbot+0d5283dca94c28f7d52d@syzkaller.appspotmail.com
First crash: 63d, last: 63d

Sample crash report:
------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(chain_key != INITIAL_CHAIN_KEY)
WARNING: CPU: 0 PID: 3855 at kernel/locking/lockdep.c:5031 __lock_acquire+0x1a0f/0x5660 kernel/locking/lockdep.c:5031
Modules linked in:
CPU: 0 PID: 3855 Comm: syz-executor.2 Not tainted 5.19.0-rc7-syzkaller-00199-g8288c99fc263 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
RIP: 0010:__lock_acquire+0x1a0f/0x5660 kernel/locking/lockdep.c:5031
Code: d2 0f 85 d4 28 00 00 44 8b 35 55 f2 b3 07 45 85 f6 0f 85 32 f4 ff ff 48 c7 c6 40 cc 47 86 48 c7 c7 e0 9b 47 86 e8 ac 94 96 04 <0f> 0b e9 1b f4 ff ff 48 c7 c2 00 96 91 8b 48 b8 00 00 00 00 00 fc
RSP: 0018:ffffc900016cf858 EFLAGS: 00010082
RAX: 0000000000000000 RBX: 000000000000002c RCX: 0000000000000000
RDX: ffff888110643900 RSI: ffffffff812c21e8 RDI: fffff520002d9efd
RBP: ffff88811064431a R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000002 R11: 0000000000000001 R12: ffff8881106442f8
R13: ffff888110643900 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f1c31d7f700(0000) GS:ffff8881f6800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5c285b4d60 CR3: 00000001104c6000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lock_acquire kernel/locking/lockdep.c:5665 [inline]
 lock_acquire+0x1ab/0x570 kernel/locking/lockdep.c:5630
 do_write_seqcount_begin_nested include/linux/seqlock.h:516 [inline]
 do_write_seqcount_begin include/linux/seqlock.h:541 [inline]
 vtime_task_switch_generic+0xb5/0x5a0 kernel/sched/cputime.c:768
 vtime_task_switch include/linux/vtime.h:95 [inline]
 finish_task_switch.isra.0+0x4e3/0xa10 kernel/sched/core.c:5020
 context_switch kernel/sched/core.c:5149 [inline]
 __schedule+0x947/0x2630 kernel/sched/core.c:6458
 schedule+0xd2/0x1f0 kernel/sched/core.c:6530
 schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1911
 ___down_common kernel/locking/semaphore.c:225 [inline]
 __down_common+0x363/0x770 kernel/locking/semaphore.c:246
 down_interruptible+0x7b/0xa0 kernel/locking/semaphore.c:87
 raw_event_queue_fetch drivers/usb/gadget/legacy/raw_gadget.c:99 [inline]
 raw_ioctl_event_fetch drivers/usb/gadget/legacy/raw_gadget.c:588 [inline]
 raw_ioctl+0x1010/0x2780 drivers/usb/gadget/legacy/raw_gadget.c:1256
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f1c32608fc7
Code: 3c 1c 48 f7 d8 49 39 c4 72 b8 e8 34 54 02 00 85 c0 78 bd 48 83 c4 08 4c 89 e0 5b 41 5c c3 0f 1f 44 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1c31d7d098 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f1c31d7e110 RCX: 00007f1c32608fc7
RDX: 00007f1c31d7e110 RSI: 0000000080085502 RDI: 0000000000000003
RBP: 0000000000000003 R08: 000000000000ffff R09: 000000000000000b
R10: 00007f1c31d7d140 R11: 0000000000000246 R12: 0000000800000000
R13: 0000000000000000 R14: 0000000020000000 R15: 00007f1c3266ecd5
 </TASK>

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-usb 2022/08/04 18:29 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 8288c99fc263 1c9013ac .config log report info WARNING: locking bug in vtime_task_switch_generic
* Struck through repros no longer work on HEAD.