Hello, syzbot found the following issue on: HEAD commit: 1dc3731daf1f Merge tag 'for-6.4-rc1-tag' of git://git.kern.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=153dd834280000 kernel config: https://syzkaller.appspot.com/x/.config?x=8bc832f563d8bf38 dashboard link: https://syzkaller.appspot.com/bug?extid=fe0c72f0ccbb93786380 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 userspace arch: i386 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-1dc3731d.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/9ac41c523f85/vmlinux-1dc3731d.xz kernel image: https://storage.googleapis.com/syzbot-assets/40b82936b92f/bzImage-1dc3731d.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+fe0c72f0ccbb93786380@xxxxxxxxxxxxxxxxxxxxxxxxx ====================================================== WARNING: possible circular locking dependency detected 6.4.0-rc1-syzkaller-00011-g1dc3731daf1f #0 Not tainted ------------------------------------------------------ kworker/u16:0/11 is trying to acquire lock: ffff88807ffdaba0 (&pgdat->kswapd_wait){....}-{2:2}, at: __wake_up_common_lock+0xb8/0x140 kernel/sched/wait.c:137 but task is already holding lock: ffff88802c7296d8 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x69c/0xe80 kernel/time/timer.c:1112 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&base->lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162 lock_timer_base+0x5a/0x1f0 kernel/time/timer.c:999 __mod_timer+0x3f9/0xe80 kernel/time/timer.c:1080 add_timer+0x62/0x90 kernel/time/timer.c:1244 __queue_delayed_work+0x1a7/0x270 kernel/workqueue.c:1685 queue_delayed_work_on+0x109/0x120 kernel/workqueue.c:1710 psi_task_change+0x1bf/0x300 kernel/sched/psi.c:920 psi_enqueue kernel/sched/stats.h:139 [inline] enqueue_task kernel/sched/core.c:2078 [inline] activate_task kernel/sched/core.c:2112 [inline] wake_up_new_task+0xc13/0x1000 kernel/sched/core.c:4833 kernel_clone+0x219/0x890 kernel/fork.c:2949 user_mode_thread+0xb1/0xf0 kernel/fork.c:2996 rest_init+0x27/0x2b0 init/main.c:700 arch_call_rest_init+0x13/0x30 init/main.c:834 start_kernel+0x3b6/0x490 init/main.c:1088 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:556 x86_64_start_kernel+0xb3/0xc0 arch/x86/kernel/head64.c:537 secondary_startup_64_no_verify+0xf4/0xfb -> #2 (&rq->__lock){-.-.}-{2:2}: _raw_spin_lock_nested+0x34/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x2f/0x120 kernel/sched/core.c:558 raw_spin_rq_lock kernel/sched/sched.h:1366 [inline] rq_lock kernel/sched/sched.h:1653 [inline] task_fork_fair+0x74/0x4f0 kernel/sched/fair.c:12095 sched_cgroup_fork+0x3d1/0x540 kernel/sched/core.c:4777 copy_process+0x4b8a/0x7600 kernel/fork.c:2618 kernel_clone+0xeb/0x890 kernel/fork.c:2918 user_mode_thread+0xb1/0xf0 kernel/fork.c:2996 rest_init+0x27/0x2b0 init/main.c:700 arch_call_rest_init+0x13/0x30 init/main.c:834 start_kernel+0x3b6/0x490 init/main.c:1088 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:556 x86_64_start_kernel+0xb3/0xc0 arch/x86/kernel/head64.c:537 secondary_startup_64_no_verify+0xf4/0xfb -> #1 (&p->pi_lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162 try_to_wake_up+0xab/0x1c40 kernel/sched/core.c:4191 autoremove_wake_function+0x16/0x150 kernel/sched/wait.c:419 __wake_up_common+0x147/0x650 kernel/sched/wait.c:107 __wake_up_common_lock+0xd4/0x140 kernel/sched/wait.c:138 wakeup_kswapd+0x3fe/0x5c0 mm/vmscan.c:7797 rmqueue mm/page_alloc.c:3057 [inline] get_page_from_freelist+0x6c5/0x2c00 mm/page_alloc.c:3499 __alloc_pages+0x1cb/0x4a0 mm/page_alloc.c:4768 __folio_alloc+0x16/0x40 mm/page_alloc.c:4800 vma_alloc_folio+0x155/0x890 mm/mempolicy.c:2240 wp_page_copy mm/memory.c:3070 [inline] do_wp_page+0x173d/0x33c0 mm/memory.c:3432 handle_pte_fault mm/memory.c:4964 [inline] __handle_mm_fault+0x1635/0x41c0 mm/memory.c:5089 handle_mm_fault+0x2af/0x9f0 mm/memory.c:5243 do_user_addr_fault+0x2ca/0x1210 arch/x86/mm/fault.c:1349 handle_page_fault arch/x86/mm/fault.c:1534 [inline] exc_page_fault+0x98/0x170 arch/x86/mm/fault.c:1590 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570 -> #0 (&pgdat->kswapd_wait){....}-{2:2}: check_prev_add kernel/locking/lockdep.c:3108 [inline] check_prevs_add kernel/locking/lockdep.c:3227 [inline] validate_chain kernel/locking/lockdep.c:3842 [inline] __lock_acquire+0x2f21/0x5df0 kernel/locking/lockdep.c:5074 lock_acquire kernel/locking/lockdep.c:5691 [inline] lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5656 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162 __wake_up_common_lock+0xb8/0x140 kernel/sched/wait.c:137 wakeup_kswapd+0x3fe/0x5c0 mm/vmscan.c:7797 wake_all_kswapds+0x182/0x2d0 mm/page_alloc.c:4028 __alloc_pages_slowpath.constprop.0+0x1724/0x2170 mm/page_alloc.c:4296 __alloc_pages+0x408/0x4a0 mm/page_alloc.c:4781 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2279 alloc_slab_page mm/slub.c:1851 [inline] allocate_slab+0x25f/0x390 mm/slub.c:1998 new_slab mm/slub.c:2051 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3192 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3291 __slab_alloc_node mm/slub.c:3344 [inline] slab_alloc_node mm/slub.c:3441 [inline] slab_alloc mm/slub.c:3459 [inline] __kmem_cache_alloc_lru mm/slub.c:3466 [inline] kmem_cache_alloc+0x38e/0x3b0 mm/slub.c:3475 kmem_cache_zalloc include/linux/slab.h:670 [inline] fill_pool+0x264/0x5c0 lib/debugobjects.c:168 debug_objects_fill_pool lib/debugobjects.c:597 [inline] debug_object_activate+0xfd/0x400 lib/debugobjects.c:693 debug_timer_activate kernel/time/timer.c:782 [inline] __mod_timer+0x80d/0xe80 kernel/time/timer.c:1119 add_timer+0x62/0x90 kernel/time/timer.c:1244 __queue_delayed_work+0x1a7/0x270 kernel/workqueue.c:1685 queue_delayed_work_on+0x109/0x120 kernel/workqueue.c:1710 process_one_work+0x99a/0x15e0 kernel/workqueue.c:2405 worker_thread+0x67d/0x10c0 kernel/workqueue.c:2552 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 other info that might help us debug this: Chain exists of: &pgdat->kswapd_wait --> &rq->__lock --> &base->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&base->lock); lock(&rq->__lock); lock(&base->lock); lock(&pgdat->kswapd_wait); *** DEADLOCK *** 3 locks held by kworker/u16:0/11: #0: ffff8880444ff138 ((wq_completion)bat_events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880444ff138 ((wq_completion)bat_events){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff8880444ff138 ((wq_completion)bat_events){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1324 [inline] #0: ffff8880444ff138 ((wq_completion)bat_events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:643 [inline] #0: ffff8880444ff138 ((wq_completion)bat_events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:670 [inline] #0: ffff8880444ff138 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work+0x883/0x15e0 kernel/workqueue.c:2376 #1: ffffc900003d7db0 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x15e0 kernel/workqueue.c:2380 #2: ffff88802c7296d8 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x69c/0xe80 kernel/time/timer.c:1112 stack backtrace: CPU: 1 PID: 11 Comm: kworker/u16:0 Not tainted 6.4.0-rc1-syzkaller-00011-g1dc3731daf1f #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Workqueue: bat_events batadv_nc_worker Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2188 check_prev_add kernel/locking/lockdep.c:3108 [inline] check_prevs_add kernel/locking/lockdep.c:3227 [inline] validate_chain kernel/locking/lockdep.c:3842 [inline] __lock_acquire+0x2f21/0x5df0 kernel/locking/lockdep.c:5074 lock_acquire kernel/locking/lockdep.c:5691 [inline] lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5656 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3d/0x60 kernel/locking/spinlock.c:162 __wake_up_common_lock+0xb8/0x140 kernel/sched/wait.c:137 wakeup_kswapd+0x3fe/0x5c0 mm/vmscan.c:7797 wake_all_kswapds+0x182/0x2d0 mm/page_alloc.c:4028 __alloc_pages_slowpath.constprop.0+0x1724/0x2170 mm/page_alloc.c:4296 __alloc_pages+0x408/0x4a0 mm/page_alloc.c:4781 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2279 alloc_slab_page mm/slub.c:1851 [inline] allocate_slab+0x25f/0x390 mm/slub.c:1998 new_slab mm/slub.c:2051 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3192 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3291 __slab_alloc_node mm/slub.c:3344 [inline] slab_alloc_node mm/slub.c:3441 [inline] slab_alloc mm/slub.c:3459 [inline] __kmem_cache_alloc_lru mm/slub.c:3466 [inline] kmem_cache_alloc+0x38e/0x3b0 mm/slub.c:3475 kmem_cache_zalloc include/linux/slab.h:670 [inline] fill_pool+0x264/0x5c0 lib/debugobjects.c:168 debug_objects_fill_pool lib/debugobjects.c:597 [inline] debug_object_activate+0xfd/0x400 lib/debugobjects.c:693 debug_timer_activate kernel/time/timer.c:782 [inline] __mod_timer+0x80d/0xe80 kernel/time/timer.c:1119 add_timer+0x62/0x90 kernel/time/timer.c:1244 __queue_delayed_work+0x1a7/0x270 kernel/workqueue.c:1685 queue_delayed_work_on+0x109/0x120 kernel/workqueue.c:1710 process_one_work+0x99a/0x15e0 kernel/workqueue.c:2405 worker_thread+0x67d/0x10c0 kernel/workqueue.c:2552 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 </TASK> --- 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 syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the bug is already fixed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to change bug's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the bug is a duplicate of another bug, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
