On Sun, Apr 04, 2021 at 10:38:41PM +0200, Thomas Gleixner wrote: > On Sun, Apr 04 2021 at 12:05, syzbot wrote: > > Cc + ...
And a couple more... > > Hello, > > > > syzbot found the following issue on: > > > > HEAD commit: 5e46d1b7 reiserfs: update reiserfs_xattrs_initialized() co.. > > git tree: upstream > > console output: https://syzkaller.appspot.com/x/log.txt?x=1125f831d00000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=78ef1d159159890 > > dashboard link: https://syzkaller.appspot.com/bug?extid=88e4f02896967fe1ab0d > > > > Unfortunately, I don't have any reproducer for this issue yet. > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: syzbot+88e4f02896967fe1a...@syzkaller.appspotmail.com > > > > ============================= > > WARNING: suspicious RCU usage > > 5.12.0-rc5-syzkaller #0 Not tainted > > ----------------------------- > > kernel/sched/core.c:8294 Illegal context switch in RCU-sched read-side > > critical section! > > > > other info that might help us debug this: > > > > > > rcu_scheduler_active = 2, debug_locks = 0 > > 3 locks held by syz-executor.4/8418: > > #0: > > ffff8880751d2b28 > > ( > > &p->pi_lock > > ){-.-.}-{2:2} > > , at: try_to_wake_up+0x98/0x14a0 kernel/sched/core.c:3345 > > #1: > > ffff8880b9d35258 > > ( > > &rq->lock > > ){-.-.}-{2:2} > > , at: rq_lock kernel/sched/sched.h:1321 [inline] > > , at: ttwu_queue kernel/sched/core.c:3184 [inline] > > , at: try_to_wake_up+0x5e6/0x14a0 kernel/sched/core.c:3464 > > #2: ffff8880b9d1f948 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, > > at: psi_task_change+0x142/0x220 kernel/sched/psi.c:807 This looks similar to syzbot+dde0cc33951735441...@syzkaller.appspotmail.com in that rcu_sleep_check() sees an RCU lock held, but the later call to lockdep_print_held_locks() does not. Did something change recently that could let the ->lockdep_depth counter get out of sync with the actual number of locks held? Thanx, Paul > > stack backtrace: > > CPU: 0 PID: 8418 Comm: syz-executor.4 Not tainted 5.12.0-rc5-syzkaller #0 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > > Google 01/01/2011 > > Call Trace: > > __dump_stack lib/dump_stack.c:79 [inline] > > dump_stack+0x141/0x1d7 lib/dump_stack.c:120 > > ___might_sleep+0x266/0x2c0 kernel/sched/core.c:8294 > > __might_fault+0x6e/0x180 mm/memory.c:5018 > > _copy_from_user+0x27/0x180 lib/usercopy.c:13 > > copy_from_user include/linux/uaccess.h:192 [inline] > > get_timespec64+0x75/0x220 kernel/time/time.c:787 > > __do_sys_clock_nanosleep kernel/time/posix-timers.c:1257 [inline] > > __se_sys_clock_nanosleep kernel/time/posix-timers.c:1245 [inline] > > __x64_sys_clock_nanosleep+0x1bb/0x430 kernel/time/posix-timers.c:1245 > > do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 > > entry_SYSCALL_64_after_hwframe+0x44/0xae > > RIP: 0033:0x48a621 > > Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 aa e7 ff ff 4c 8b 54 24 18 48 8b 54 > > 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 > > 04 24 e8 e3 e7 ff ff 48 8b 04 24 eb 97 66 2e 0f 1f > > RSP: 002b:00007fffe59fbd50 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 > > RAX: ffffffffffffffda RBX: 0000000000000294 RCX: 000000000048a621 > > RDX: 00007fffe59fbd90 RSI: 0000000000000000 RDI: 0000000000000000 > > RBP: 00007fffe59fbe2c R08: 0000000000000000 R09: 00007fffe5b8a090 > > R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000032 > > R13: 000000000005717a R14: 0000000000000003 R15: 00007fffe59fbe90 > > > > > > --- > > This report is generated by a bot. It may contain errors. > > See https://goo.gl/tpsmEJ for more information about syzbot. > > syzbot engineers can be reached at syzkal...@googlegroups.com. > > > > syzbot will keep track of this issue. See: > > https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
