============================= WARNING: suspicious RCU usage 5.9.0-next-20201016-syzkaller #0 Not tainted ----------------------------- include/linux/cgroup.h:494 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 no locks held by syz-executor.2/8276. stack backtrace: CPU: 1 PID: 8276 Comm: syz-executor.2 Not tainted 5.9.0-next-20201016-syzkaller #0 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+0x198/0x1fb lib/dump_stack.c:118 task_css include/linux/cgroup.h:494 [inline] blkcg_css include/linux/blk-cgroup.h:224 [inline] blkcg_css include/linux/blk-cgroup.h:217 [inline] io_init_identity+0x3a9/0x450 fs/io_uring.c:1052 io_uring_alloc_task_context+0x176/0x250 fs/io_uring.c:7730 io_sq_offload_create fs/io_uring.c:7801 [inline] io_uring_create fs/io_uring.c:9269 [inline] io_uring_setup+0x264a/0x3660 fs/io_uring.c:9342 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45de59 Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fc1f2683bf8 EFLAGS: 00000206 ORIG_RAX: 00000000000001a9 RAX: ffffffffffffffda RBX: 0000000020000040 RCX: 000000000045de59 RDX: 0000000020ffd000 RSI: 0000000020000040 RDI: 0000000000003f7d RBP: 000000000118bf78 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020ffd000 R13: 0000000020ffd000 R14: 0000000000000000 R15: 0000000000000000 BUG: using __this_cpu_read() in preemptible [00000000] code: syz-executor.2/8276 caller is lockdep_hardirqs_on_prepare+0x5e/0x450 kernel/locking/lockdep.c:4060 CPU: 1 PID: 8276 Comm: syz-executor.2 Not tainted 5.9.0-next-20201016-syzkaller #0 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+0x198/0x1fb lib/dump_stack.c:118 check_preemption_disabled+0x128/0x130 lib/smp_processor_id.c:48 lockdep_hardirqs_on_prepare+0x5e/0x450 kernel/locking/lockdep.c:4060 trace_hardirqs_on+0x5b/0x1c0 kernel/trace/trace_preemptirq.c:49 __bad_area_nosemaphore+0xc6/0x4f0 arch/x86/mm/fault.c:797 do_user_addr_fault+0x852/0xbf0 arch/x86/mm/fault.c:1335 handle_page_fault arch/x86/mm/fault.c:1429 [inline] exc_page_fault+0xa8/0x190 arch/x86/mm/fault.c:1482 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:583 RIP: 0033:0x4024cb Code: 40 41 89 e8 4c 89 ef b9 11 80 00 00 c1 e6 04 03 73 64 8d 14 90 39 f2 48 0f 43 f2 45 31 c9 ba 03 00 00 00 e8 a7 b9 05 00 8b 33 <49> 89 07 41 89 e8 4c 89 e7 41 b9 00 00 00 10 b9 11 80 00 00 ba 03 RSP: 002b:00007fc1f2683c00 EFLAGS: 00010207 RAX: 0000000020ffd000 RBX: 0000000020000040 RCX: 000000000045deaa RDX: 0000000000000003 RSI: 0000000000004000 RDI: 0000000020ffd000 RBP: 0000000000000003 R08: 0000000000000003 R09: 0000000000000000 R10: 0000000000008011 R11: 0000000000000206 R12: 0000000020ffd000 R13: 0000000020ffd000 R14: 0000000000000000 R15: 0000000000000000 BUG: using __this_cpu_read() in preemptible [00000000] code: syz-executor.2/8276 caller is lockdep_hardirqs_on+0x34/0x110 kernel/locking/lockdep.c:4129 CPU: 1 PID: 8276 Comm: syz-executor.2 Not tainted 5.9.0-next-20201016-syzkaller #0 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+0x198/0x1fb lib/dump_stack.c:118 check_preemption_disabled+0x128/0x130 lib/smp_processor_id.c:48 lockdep_hardirqs_on+0x34/0x110 kernel/locking/lockdep.c:4129 __bad_area_nosemaphore+0xc6/0x4f0 arch/x86/mm/fault.c:797 do_user_addr_fault+0x852/0xbf0 arch/x86/mm/fault.c:1335 handle_page_fault arch/x86/mm/fault.c:1429 [inline] exc_page_fault+0xa8/0x190 arch/x86/mm/fault.c:1482 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:583 RIP: 0033:0x4024cb Code: 40 41 89 e8 4c 89 ef b9 11 80 00 00 c1 e6 04 03 73 64 8d 14 90 39 f2 48 0f 43 f2 45 31 c9 ba 03 00 00 00 e8 a7 b9 05 00 8b 33 <49> 89 07 41 89 e8 4c 89 e7 41 b9 00 00 00 10 b9 11 80 00 00 ba 03 RSP: 002b:00007fc1f2683c00 EFLAGS: 00010207 RAX: 0000000020ffd000 RBX: 0000000020000040 RCX: 000000000045deaa RDX: 0000000000000003 RSI: 0000000000004000 RDI: 0000000020ffd000 RBP: 0000000000000003 R08: 0000000000000003 R09: 0000000000000000 R10: 0000000000008011 R11: 0000000000000206 R12: 0000000020ffd000 R13: 0000000020ffd000 R14: 0000000000000000 R15: 0000000000000000 BUG: using __this_cpu_read() in preemptible [00000000] code: syz-executor.2/8276 caller is lockdep_hardirqs_on_prepare+0x5e/0x450 kernel/locking/lockdep.c:4060 CPU: 1 PID: 8276 Comm: syz-executor.2 Not tainted 5.9.0-next-20201016-syzkaller #0 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+0x198/0x1fb lib/dump_stack.c:118 check_preemption_disabled+0x128/0x130 lib/smp_processor_id.c:48 lockdep_hardirqs_on_prepare+0x5e/0x450 kernel/locking/lockdep.c:4060 trace_hardirqs_on+0x5b/0x1c0 kernel/trace/trace_preemptirq.c:49 __bad_area_nosemaphore+0xc6/0x4f0 arch/x86/mm/fault.c:797 do_user_addr_fault+0x852/0xbf0 arch/x86/mm/fault.c:1335 handle_page_fault arch/x86/mm/fault.c:1429 [inline] exc_page_fault+0xa8/0x190 arch/x86/mm/fault.c:1482 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:583 RIP: 0033:0x4024cb Code: 40 41 89 e8 4c 89 ef b9 11 80 00 00 c1 e6 04 03 73 64 8d 14 90 39 f2 48 0f 43 f2 45 31 c9 ba 03 00 00 00 e8 a7 b9 05 00 8b 33 <49> 89 07 41 89 e8 4c 89 e7 41 b9 00 00 00 10 b9 11 80 00 00 ba 03 RSP: 002b:00007fc1f2683c00 EFLAGS: 00010207 RAX: 0000000020ffd000 RBX: 0000000020000040 RCX: 000000000045deaa RDX: 0000000000000003 RSI: 0000000000004000 RDI: 0000000020ffd000 RBP: 0000000000000003 R08: 0000000000000003 R09: 0000000000000000 R10: 0000000000008011 R11: 0000000000000206 R12: 0000000020ffd000 R13: 0000000020ffd000 R14: 0000000000000000 R15: 0000000000000000 BUG: using __this_cpu_read() in preemptible [00000000] code: syz-executor.2/8276 caller is lockdep_hardirqs_on+0x34/0x110 kernel/locking/lockdep.c:4129 CPU: 1 PID: 8276 Comm: syz-executor.2 Not tainted 5.9.0-next-20201016-syzkaller #0 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+0x198/0x1fb lib/dump_stack.c:118 check_preemption_disabled+0x128/0x130 lib/smp_processor_id.c:48 lockdep_hardirqs_on+0x34/0x110 kernel/locking/lockdep.c:4129 __bad_area_nosemaphore+0xc6/0x4f0 arch/x86/mm/fault.c:797 do_user_addr_fault+0x852/0xbf0 arch/x86/mm/fault.c:1335 handle_page_fault arch/x86/mm/fault.c:1429 [inline] exc_page_fault+0xa8/0x190 arch/x86/mm/fault.c:1482 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:583 RIP: 0033:0x4024cb Code: 40 41 89 e8 4c 89 ef b9 11 80 00 00 c1 e6 04 03 73 64 8d 14 90 39 f2 48 0f 43 f2 45 31 c9 ba 03 00 00 00 e8 a7 b9 05 00 8b 33 <49> 89 07 41 89 e8 4c 89 e7 41 b9 00 00 00 10 b9 11 80 00 00 ba 03 RSP: 002b:00007fc1f2683c00 EFLAGS: 00010207 RAX: 0000000020ffd000 RBX: 0000000020000040 RCX: 000000000045deaa RDX: 0000000000000003 RSI: 0000000000004000 RDI: 0000000020ffd000 RBP: 0000000000000003 R08: 0000000000000003 R09: 0000000000000000 R10: 0000000000008011 R11: 0000000000000206 R12: 0000000020ffd000 R13: 0000000020ffd000 R14: 0000000000000000 R15: 0000000000000000