Hello, syzbot found the following issue on: HEAD commit: 88b06399 Merge tag 'for-5.13-rc1-part2-tag' of git://git.k.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=11d47145d00000 kernel config: https://syzkaller.appspot.com/x/.config?x=e4fa783e79fe30c8 dashboard link: https://syzkaller.appspot.com/bug?extid=a9bb2f97117a3bb1b77d 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+a9bb2f97117a3bb1b77d@xxxxxxxxxxxxxxxxxxxxxxxxx ====================================================== WARNING: possible circular locking dependency detected 5.13.0-rc1-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.0/9979 is trying to acquire lock: ffff88803ffffba0 (&pgdat->kswapd_wait){..-.}-{2:2}, at: __wake_up_common_lock+0xb4/0x130 kernel/sched/wait.c:137 but task is already holding lock: ffff88802cd35358 (&rq->lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1334 [inline] ffff88802cd35358 (&rq->lock){-.-.}-{2:2}, at: __schedule+0x21c/0x23e0 kernel/sched/core.c:5061 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&rq->lock){-.-.}-{2:2}: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 rq_lock kernel/sched/sched.h:1334 [inline] task_fork_fair+0x74/0x4d0 kernel/sched/fair.c:10795 sched_fork+0x3fc/0xbd0 kernel/sched/core.c:3792 copy_process+0x1f32/0x7120 kernel/fork.c:2086 kernel_clone+0xe7/0xab0 kernel/fork.c:2503 kernel_thread+0xb5/0xf0 kernel/fork.c:2555 rest_init+0x23/0x388 init/main.c:687 start_kernel+0x475/0x496 init/main.c:1087 secondary_startup_64_no_verify+0xb0/0xbb -> #1 (&p->pi_lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 try_to_wake_up+0x98/0x14b0 kernel/sched/core.c:3364 autoremove_wake_function+0x12/0x140 kernel/sched/wait.c:404 __wake_up_common+0x147/0x650 kernel/sched/wait.c:108 __wake_up_common_lock+0xd0/0x130 kernel/sched/wait.c:138 wakeup_kswapd+0x3f8/0x640 mm/vmscan.c:4185 rmqueue mm/page_alloc.c:3572 [inline] get_page_from_freelist+0x17bd/0x2b60 mm/page_alloc.c:3991 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5200 alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2272 __page_cache_alloc mm/filemap.c:1005 [inline] __page_cache_alloc+0x303/0x3a0 mm/filemap.c:990 pagecache_get_page+0x38f/0x18d0 mm/filemap.c:1885 grab_cache_page_write_begin+0x64/0x90 mm/filemap.c:3610 ext4_da_write_begin+0x35c/0x1160 fs/ext4/inode.c:2984 generic_perform_write+0x20a/0x4f0 mm/filemap.c:3660 ext4_buffered_write_iter+0x244/0x4d0 fs/ext4/file.c:269 ext4_file_write_iter+0x423/0x14e0 fs/ext4/file.c:680 call_write_iter include/linux/fs.h:2114 [inline] new_sync_write+0x426/0x650 fs/read_write.c:518 vfs_write+0x796/0xa30 fs/read_write.c:605 ksys_write+0x12d/0x250 fs/read_write.c:658 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #0 (&pgdat->kswapd_wait){..-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:2938 [inline] check_prevs_add kernel/locking/lockdep.c:3061 [inline] validate_chain kernel/locking/lockdep.c:3676 [inline] __lock_acquire+0x2a17/0x5230 kernel/locking/lockdep.c:4902 lock_acquire kernel/locking/lockdep.c:5512 [inline] lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5477 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 __wake_up_common_lock+0xb4/0x130 kernel/sched/wait.c:137 wakeup_kswapd+0x3f8/0x640 mm/vmscan.c:4185 wake_all_kswapds+0x143/0x2c0 mm/page_alloc.c:4484 __alloc_pages_slowpath.constprop.0+0x17c1/0x2140 mm/page_alloc.c:4756 __alloc_pages+0x422/0x500 mm/page_alloc.c:5213 alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2272 stack_depot_save+0x39d/0x4e0 lib/stackdepot.c:303 kasan_save_stack+0x32/0x40 mm/kasan/common.c:40 kasan_record_aux_stack+0xa4/0xd0 mm/kasan/generic.c:345 irq_work_queue_on+0x9f/0x160 kernel/irq_work.c:104 balance_rt+0x202/0x2c0 kernel/sched/rt.c:1541 put_prev_task_balance kernel/sched/core.c:4934 [inline] pick_next_task kernel/sched/core.c:4974 [inline] __schedule+0x134c/0x23e0 kernel/sched/core.c:5111 schedule+0xcf/0x270 kernel/sched/core.c:5226 schedule_timeout+0x14a/0x250 kernel/time/timer.c:1892 io_schedule_timeout+0xcb/0x140 kernel/sched/core.c:7203 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common_io kernel/sched/completion.c:123 [inline] wait_for_completion_io_timeout+0x163/0x280 kernel/sched/completion.c:191 submit_bio_wait+0x158/0x230 block/bio.c:1160 blkdev_issue_flush+0xd6/0x130 block/blk-flush.c:446 ext4_sync_file+0x60b/0xfd0 fs/ext4/fsync.c:177 vfs_fsync_range+0x13a/0x220 fs/sync.c:200 generic_write_sync include/linux/fs.h:2982 [inline] ext4_buffered_write_iter+0x36a/0x4d0 fs/ext4/file.c:277 ext4_file_write_iter+0x423/0x14e0 fs/ext4/file.c:680 call_write_iter include/linux/fs.h:2114 [inline] do_iter_readv_writev+0x46f/0x740 fs/read_write.c:740 do_iter_write+0x188/0x670 fs/read_write.c:866 vfs_iter_write+0x70/0xa0 fs/read_write.c:907 iter_file_splice_write+0x6fa/0xc10 fs/splice.c:689 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x110/0x180 fs/splice.c:936 splice_direct_to_actor+0x34b/0x8c0 fs/splice.c:891 do_splice_direct+0x1b3/0x280 fs/splice.c:979 do_sendfile+0x9f0/0x1110 fs/read_write.c:1260 __do_sys_sendfile64 fs/read_write.c:1319 [inline] __se_sys_sendfile64 fs/read_write.c:1311 [inline] __x64_sys_sendfile64+0x149/0x210 fs/read_write.c:1311 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Chain exists of: &pgdat->kswapd_wait --> &p->pi_lock --> &rq->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&rq->lock); lock(&p->pi_lock); lock(&rq->lock); lock(&pgdat->kswapd_wait); *** DEADLOCK *** 2 locks held by syz-executor.0/9979: #0: ffff888023830460 (sb_writers#5){.+.+}-{0:0}, at: __do_sys_sendfile64 fs/read_write.c:1319 [inline] #0: ffff888023830460 (sb_writers#5){.+.+}-{0:0}, at: __se_sys_sendfile64 fs/read_write.c:1311 [inline] #0: ffff888023830460 (sb_writers#5){.+.+}-{0:0}, at: __x64_sys_sendfile64+0x149/0x210 fs/read_write.c:1311 #1: ffff88802cd35358 (&rq->lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1334 [inline] #1: ffff88802cd35358 (&rq->lock){-.-.}-{2:2}, at: __schedule+0x21c/0x23e0 kernel/sched/core.c:5061 stack backtrace: CPU: 3 PID: 9979 Comm: syz-executor.0 Not tainted 5.13.0-rc1-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x141/0x1d7 lib/dump_stack.c:120 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2129 check_prev_add kernel/locking/lockdep.c:2938 [inline] check_prevs_add kernel/locking/lockdep.c:3061 [inline] validate_chain kernel/locking/lockdep.c:3676 [inline] __lock_acquire+0x2a17/0x5230 kernel/locking/lockdep.c:4902 lock_acquire kernel/locking/lockdep.c:5512 [inline] lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5477 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:159 __wake_up_common_lock+0xb4/0x130 kernel/sched/wait.c:137 wakeup_kswapd+0x3f8/0x640 mm/vmscan.c:4185 wake_all_kswapds+0x143/0x2c0 mm/page_alloc.c:4484 __alloc_pages_slowpath.constprop.0+0x17c1/0x2140 mm/page_alloc.c:4756 __alloc_pages+0x422/0x500 mm/page_alloc.c:5213 alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2272 stack_depot_save+0x39d/0x4e0 lib/stackdepot.c:303 kasan_save_stack+0x32/0x40 mm/kasan/common.c:40 kasan_record_aux_stack+0xa4/0xd0 mm/kasan/generic.c:345 irq_work_queue_on+0x9f/0x160 kernel/irq_work.c:104 balance_rt+0x202/0x2c0 kernel/sched/rt.c:1541 put_prev_task_balance kernel/sched/core.c:4934 [inline] pick_next_task kernel/sched/core.c:4974 [inline] __schedule+0x134c/0x23e0 kernel/sched/core.c:5111 schedule+0xcf/0x270 kernel/sched/core.c:5226 schedule_timeout+0x14a/0x250 kernel/time/timer.c:1892 io_schedule_timeout+0xcb/0x140 kernel/sched/core.c:7203 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common_io kernel/sched/completion.c:123 [inline] wait_for_completion_io_timeout+0x163/0x280 kernel/sched/completion.c:191 submit_bio_wait+0x158/0x230 block/bio.c:1160 blkdev_issue_flush+0xd6/0x130 block/blk-flush.c:446 ext4_sync_file+0x60b/0xfd0 fs/ext4/fsync.c:177 vfs_fsync_range+0x13a/0x220 fs/sync.c:200 generic_write_sync include/linux/fs.h:2982 [inline] ext4_buffered_write_iter+0x36a/0x4d0 fs/ext4/file.c:277 ext4_file_write_iter+0x423/0x14e0 fs/ext4/file.c:680 call_write_iter include/linux/fs.h:2114 [inline] do_iter_readv_writev+0x46f/0x740 fs/read_write.c:740 do_iter_write+0x188/0x670 fs/read_write.c:866 vfs_iter_write+0x70/0xa0 fs/read_write.c:907 iter_file_splice_write+0x6fa/0xc10 fs/splice.c:689 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x110/0x180 fs/splice.c:936 splice_direct_to_actor+0x34b/0x8c0 fs/splice.c:891 do_splice_direct+0x1b3/0x280 fs/splice.c:979 do_sendfile+0x9f0/0x1110 fs/read_write.c:1260 __do_sys_sendfile64 fs/read_write.c:1319 [inline] __se_sys_sendfile64 fs/read_write.c:1311 [inline] __x64_sys_sendfile64+0x149/0x210 fs/read_write.c:1311 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665f9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f354f1c3188 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 000000000056c158 RCX: 00000000004665f9 RDX: 0000000020000100 RSI: 0000000000000006 RDI: 0000000000000006 RBP: 00000000004bfce1 R08: 0000000000000000 R09: 0000000000000000 R10: 00008080ffffff80 R11: 0000000000000246 R12: 000000000056c158 R13: 00007fff4004641f R14: 00007f354f1c3300 R15: 0000000000022000 --- This report is generated by a bot. 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