Hello, syzbot found the following issue on: HEAD commit: d72e6319 Add linux-next specific files for 20210706 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=160c5ee4300000 kernel config: https://syzkaller.appspot.com/x/.config?x=59e1e3bbc3afca75 dashboard link: https://syzkaller.appspot.com/bug?extid=96238133b569a5838d63 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+96238133b569a5838d63@xxxxxxxxxxxxxxxxxxxxxxxxx ====================================================== WARNING: possible circular locking dependency detected 5.13.0-next-20210706-syzkaller #0 Not tainted ------------------------------------------------------ syz-fuzzer/8441 is trying to acquire lock: ffffffff8ba9f5c0 (fs_reclaim){+.+.}-{0:0}, at: fs_reclaim_acquire+0xf7/0x160 mm/page_alloc.c:4585 but task is already holding lock: ffff8880b9d4d660 (lock#2){-.-.}-{2:2}, at: __alloc_pages_bulk+0x4ad/0x1870 mm/page_alloc.c:5290 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (lock#2){-.-.}-{2:2}: local_lock_acquire include/linux/local_lock_internal.h:42 [inline] rmqueue_pcplist mm/page_alloc.c:3674 [inline] rmqueue mm/page_alloc.c:3712 [inline] get_page_from_freelist+0x4aa/0x2f80 mm/page_alloc.c:4174 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5385 alloc_page_interleave+0x1e/0x200 mm/mempolicy.c:2119 alloc_pages+0x238/0x2a0 mm/mempolicy.c:2242 stack_depot_save+0x39d/0x4e0 lib/stackdepot.c:303 kasan_save_stack+0x32/0x40 mm/kasan/common.c:40 kasan_record_aux_stack+0xe5/0x110 mm/kasan/generic.c:348 insert_work+0x48/0x370 kernel/workqueue.c:1332 __queue_work+0x5c1/0xed0 kernel/workqueue.c:1498 __queue_delayed_work+0x1c8/0x270 kernel/workqueue.c:1645 mod_delayed_work_on+0xdd/0x220 kernel/workqueue.c:1719 kblockd_mod_delayed_work_on+0x26/0x30 block/blk-core.c:1633 __blk_mq_delay_run_hw_queue+0x38d/0x640 block/blk-mq.c:1585 blk_mq_run_hw_queue+0x16c/0x2f0 block/blk-mq.c:1630 blk_mq_sched_insert_request+0x368/0x450 block/blk-mq-sched.c:479 blk_mq_submit_bio+0xe5f/0x1860 block/blk-mq.c:2296 __submit_bio_noacct_mq block/blk-core.c:1011 [inline] submit_bio_noacct block/blk-core.c:1044 [inline] submit_bio_noacct+0xad2/0xf20 block/blk-core.c:1027 submit_bio+0x1ea/0x470 block/blk-core.c:1106 submit_bh_wbc+0x5eb/0x7f0 fs/buffer.c:3087 __ext4_read_bh fs/ext4/super.c:156 [inline] ext4_read_bh+0x152/0x300 fs/ext4/super.c:180 ext4_read_bh_lock+0x82/0x180 fs/ext4/super.c:192 __ext4_sb_bread_gfp.isra.0+0xf3/0x1b0 fs/ext4/super.c:224 ext4_sb_bread_unmovable fs/ext4/super.c:241 [inline] ext4_fill_super+0x233d/0xe3f0 fs/ext4/super.c:4474 mount_bdev+0x34d/0x410 fs/super.c:1368 legacy_get_tree+0x105/0x220 fs/fs_context.c:592 vfs_get_tree+0x89/0x2f0 fs/super.c:1498 do_new_mount fs/namespace.c:2905 [inline] path_mount+0x132a/0x1fa0 fs/namespace.c:3235 init_mount+0xaa/0xf4 fs/init.c:25 do_mount_root+0x9c/0x25b init/do_mounts.c:386 mount_block_root+0x32e/0x4dd init/do_mounts.c:417 mount_root+0x1af/0x1f5 init/do_mounts.c:555 prepare_namespace+0x1ff/0x234 init/do_mounts.c:607 kernel_init_freeable+0x729/0x741 init/main.c:1611 kernel_init+0x1a/0x1d0 init/main.c:1490 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 -> #1 (&pool->lock){-.-.}-{2:2}: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 __queue_work+0x366/0xed0 kernel/workqueue.c:1455 queue_work_on+0xee/0x110 kernel/workqueue.c:1525 queue_work include/linux/workqueue.h:507 [inline] schedule_work include/linux/workqueue.h:568 [inline] __vfree_deferred mm/vmalloc.c:2609 [inline] vfree_atomic+0xac/0xe0 mm/vmalloc.c:2627 free_thread_stack kernel/fork.c:292 [inline] release_task_stack kernel/fork.c:432 [inline] put_task_stack+0x2e0/0x4e0 kernel/fork.c:443 finish_task_switch.isra.0+0x75a/0xa20 kernel/sched/core.c:4601 context_switch kernel/sched/core.c:4703 [inline] __schedule+0x942/0x26f0 kernel/sched/core.c:5957 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:6345 irqentry_exit+0x31/0x80 kernel/entry/common.c:427 asm_sysvec_reschedule_ipi+0x12/0x20 arch/x86/include/asm/idtentry.h:643 lock_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5593 __fs_reclaim_acquire mm/page_alloc.c:4563 [inline] fs_reclaim_acquire+0x117/0x160 mm/page_alloc.c:4577 might_alloc include/linux/sched/mm.h:219 [inline] slab_pre_alloc_hook mm/slab.h:485 [inline] slab_alloc_node mm/slub.c:2902 [inline] slab_alloc mm/slub.c:2989 [inline] kmem_cache_alloc+0x3e/0x3a0 mm/slub.c:2994 kmem_cache_zalloc include/linux/slab.h:711 [inline] __kernfs_new_node+0xd4/0x8b0 fs/kernfs/dir.c:583 kernfs_new_node+0x93/0x120 fs/kernfs/dir.c:645 __kernfs_create_file+0x51/0x350 fs/kernfs/file.c:985 sysfs_add_file_mode_ns+0x226/0x540 fs/sysfs/file.c:317 create_files fs/sysfs/group.c:64 [inline] internal_create_group+0x328/0xb20 fs/sysfs/group.c:149 kernel_add_sysfs_param kernel/params.c:796 [inline] param_sysfs_builtin kernel/params.c:833 [inline] param_sysfs_init+0x39a/0x498 kernel/params.c:952 do_one_initcall+0x103/0x650 init/main.c:1285 do_initcall_level init/main.c:1360 [inline] do_initcalls init/main.c:1376 [inline] do_basic_setup init/main.c:1396 [inline] kernel_init_freeable+0x6b8/0x741 init/main.c:1598 kernel_init+0x1a/0x1d0 init/main.c:1490 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 -> #0 (fs_reclaim){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3051 [inline] check_prevs_add kernel/locking/lockdep.c:3174 [inline] validate_chain kernel/locking/lockdep.c:3789 [inline] __lock_acquire+0x2a07/0x54a0 kernel/locking/lockdep.c:5015 lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __fs_reclaim_acquire mm/page_alloc.c:4563 [inline] fs_reclaim_acquire+0x117/0x160 mm/page_alloc.c:4577 prepare_alloc_pages+0x15c/0x580 mm/page_alloc.c:5175 __alloc_pages+0x12f/0x500 mm/page_alloc.c:5374 alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2244 stack_depot_save+0x39d/0x4e0 lib/stackdepot.c:303 save_stack+0x15e/0x1e0 mm/page_owner.c:120 __set_page_owner+0x50/0x290 mm/page_owner.c:181 prep_new_page mm/page_alloc.c:2444 [inline] __alloc_pages_bulk+0x8b9/0x1870 mm/page_alloc.c:5312 alloc_pages_bulk_array_node include/linux/gfp.h:557 [inline] vm_area_alloc_pages mm/vmalloc.c:2793 [inline] __vmalloc_area_node mm/vmalloc.c:2863 [inline] __vmalloc_node_range+0x39d/0x960 mm/vmalloc.c:2966 __vmalloc_node mm/vmalloc.c:3015 [inline] vzalloc+0x67/0x80 mm/vmalloc.c:3085 n_tty_open+0x16/0x170 drivers/tty/n_tty.c:1848 tty_ldisc_open+0x9b/0x110 drivers/tty/tty_ldisc.c:449 tty_ldisc_setup+0x43/0x100 drivers/tty/tty_ldisc.c:766 tty_init_dev.part.0+0x1f4/0x610 drivers/tty/tty_io.c:1453 tty_init_dev include/linux/err.h:36 [inline] tty_open_by_driver drivers/tty/tty_io.c:2098 [inline] tty_open+0xb16/0x1000 drivers/tty/tty_io.c:2146 chrdev_open+0x266/0x770 fs/char_dev.c:414 do_dentry_open+0x4c8/0x11d0 fs/open.c:826 do_open fs/namei.c:3374 [inline] path_openat+0x1c23/0x27f0 fs/namei.c:3507 do_filp_open+0x1aa/0x400 fs/namei.c:3534 do_sys_openat2+0x16d/0x420 fs/open.c:1204 do_sys_open fs/open.c:1220 [inline] __do_sys_openat fs/open.c:1236 [inline] __se_sys_openat fs/open.c:1231 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1231 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+0x44/0xae other info that might help us debug this: Chain exists of: fs_reclaim --> &pool->lock --> lock#2 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(lock#2); lock(&pool->lock); lock(lock#2); lock(fs_reclaim); *** DEADLOCK *** 4 locks held by syz-fuzzer/8441: #0: ffffffff8c37b7c8 (tty_mutex){+.+.}-{3:3}, at: tty_open_by_driver drivers/tty/tty_io.c:2062 [inline] #0: ffffffff8c37b7c8 (tty_mutex){+.+.}-{3:3}, at: tty_open+0x55e/0x1000 drivers/tty/tty_io.c:2146 #1: ffff8880301c01c0 (&tty->legacy_mutex){+.+.}-{3:3}, at: tty_lock+0xbd/0x120 drivers/tty/tty_mutex.c:20 #2: ffff8880301c0098 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:300 [inline] #2: ffff8880301c0098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock+0x61/0xb0 drivers/tty/tty_ldisc.c:324 #3: ffff8880b9d4d660 (lock#2){-.-.}-{2:2}, at: __alloc_pages_bulk+0x4ad/0x1870 mm/page_alloc.c:5290 stack backtrace: CPU: 1 PID: 8441 Comm: syz-fuzzer Not tainted 5.13.0-next-20210706-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2131 check_prev_add kernel/locking/lockdep.c:3051 [inline] check_prevs_add kernel/locking/lockdep.c:3174 [inline] validate_chain kernel/locking/lockdep.c:3789 [inline] __lock_acquire+0x2a07/0x54a0 kernel/locking/lockdep.c:5015 lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __fs_reclaim_acquire mm/page_alloc.c:4563 [inline] fs_reclaim_acquire+0x117/0x160 mm/page_alloc.c:4577 prepare_alloc_pages+0x15c/0x580 mm/page_alloc.c:5175 __alloc_pages+0x12f/0x500 mm/page_alloc.c:5374 alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2244 stack_depot_save+0x39d/0x4e0 lib/stackdepot.c:303 save_stack+0x15e/0x1e0 mm/page_owner.c:120 __set_page_owner+0x50/0x290 mm/page_owner.c:181 prep_new_page mm/page_alloc.c:2444 [inline] __alloc_pages_bulk+0x8b9/0x1870 mm/page_alloc.c:5312 alloc_pages_bulk_array_node include/linux/gfp.h:557 [inline] vm_area_alloc_pages mm/vmalloc.c:2793 [inline] __vmalloc_area_node mm/vmalloc.c:2863 [inline] __vmalloc_node_range+0x39d/0x960 mm/vmalloc.c:2966 __vmalloc_node mm/vmalloc.c:3015 [inline] vzalloc+0x67/0x80 mm/vmalloc.c:3085 n_tty_open+0x16/0x170 drivers/tty/n_tty.c:1848 tty_ldisc_open+0x9b/0x110 drivers/tty/tty_ldisc.c:449 tty_ldisc_setup+0x43/0x100 drivers/tty/tty_ldisc.c:766 tty_init_dev.part.0+0x1f4/0x610 drivers/tty/tty_io.c:1453 tty_init_dev include/linux/err.h:36 [inline] tty_open_by_driver drivers/tty/tty_io.c:2098 [inline] tty_open+0xb16/0x1000 drivers/tty/tty_io.c:2146 chrdev_open+0x266/0x770 fs/char_dev.c:414 do_dentry_open+0x4c8/0x11d0 fs/open.c:826 do_open fs/namei.c:3374 [inline] path_openat+0x1c23/0x27f0 fs/namei.c:3507 do_filp_open+0x1aa/0x400 fs/namei.c:3534 do_sys_openat2+0x16d/0x420 fs/open.c:1204 do_sys_open fs/open.c:1220 [inline] __do_sys_openat fs/open.c:1236 [inline] __se_sys_openat fs/open.c:1231 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1231 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+0x44/0xae RIP: 0033:0x4af20a Code: e8 3b 82 fb ff 48 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 4c 8b 54 24 28 4c 8b 44 24 30 4c 8b 4c 24 38 48 8b 44 24 08 0f 05 <48> 3d 01 f0 ff ff 76 20 48 c7 44 24 40 ff ff ff ff 48 c7 44 24 48 RSP: 002b:000000c00036f3f8 EFLAGS: 00000216 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000000c00001c000 RCX: 00000000004af20a RDX: 0000000000000000 RSI: 000000c000167a70 RDI: ffffffffffffff9c RBP: 000000c00036f470 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000216 R12: 00000000000001a8 R13: 00000000000001a7 R14: 0000000000000200 R15: 000000c0004a9180 BUG: sleeping function called from invalid context at mm/page_alloc.c:5178 in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 8441, name: syz-fuzzer INFO: lockdep is turned off. irq event stamp: 100212 hardirqs last enabled at (100211): [<ffffffff892c0320>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] hardirqs last enabled at (100211): [<ffffffff892c0320>] _raw_spin_unlock_irqrestore+0x50/0x70 kernel/locking/spinlock.c:191 hardirqs last disabled at (100212): [<ffffffff81b277e7>] __alloc_pages_bulk+0x1017/0x1870 mm/page_alloc.c:5290 softirqs last enabled at (96960): [<ffffffff8146389e>] invoke_softirq kernel/softirq.c:432 [inline] softirqs last enabled at (96960): [<ffffffff8146389e>] __irq_exit_rcu+0x16e/0x1c0 kernel/softirq.c:636 softirqs last disabled at (96847): [<ffffffff8146389e>] invoke_softirq kernel/softirq.c:432 [inline] softirqs last disabled at (96847): [<ffffffff8146389e>] __irq_exit_rcu+0x16e/0x1c0 kernel/softirq.c:636 CPU: 1 PID: 8441 Comm: syz-fuzzer Not tainted 5.13.0-next-20210706-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105 ___might_sleep.cold+0x1f1/0x237 kernel/sched/core.c:9171 prepare_alloc_pages+0x3da/0x580 mm/page_alloc.c:5178 __alloc_pages+0x12f/0x500 mm/page_alloc.c:5374 alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2244 stack_depot_save+0x39d/0x4e0 lib/stackdepot.c:303 save_stack+0x15e/0x1e0 mm/page_owner.c:120 __set_page_owner+0x50/0x290 mm/page_owner.c:181 prep_new_page mm/page_alloc.c:2444 [inline] __alloc_pages_bulk+0x8b9/0x1870 mm/page_alloc.c:5312 alloc_pages_bulk_array_node include/linux/gfp.h:557 [inline] vm_area_alloc_pages mm/vmalloc.c:2793 [inline] __vmalloc_area_node mm/vmalloc.c:2863 [inline] __vmalloc_node_range+0x39d/0x960 mm/vmalloc.c:2966 __vmalloc_node mm/vmalloc.c:3015 [inline] vzalloc+0x67/0x80 mm/vmalloc.c:3085 n_tty_open+0x16/0x170 drivers/tty/n_tty.c:1848 tty_ldisc_open+0x9b/0x110 drivers/tty/tty_ldisc.c:449 tty_ldisc_setup+0x43/0x100 drivers/tty/tty_ldisc.c:766 tty_init_dev.part.0+0x1f4/0x610 drivers/tty/tty_io.c:1453 tty_init_dev include/linux/err.h:36 [inline] tty_open_by_driver drivers/tty/tty_io.c:2098 [inline] tty_open+0xb16/0x1000 drivers/tty/tty_io.c:2146 chrdev_open+0x266/0x770 fs/char_dev.c:414 do_dentry_open+0x4c8/0x11d0 fs/open.c:826 do_open fs/namei.c:3374 [inline] path_openat+0x1c23/0x27f0 fs/namei.c:3507 do_filp_open+0x1aa/0x400 fs/namei.c:3534 do_sys_openat2+0x16d/0x420 fs/open.c:1204 do_sys_open fs/open.c:1220 [inline] __do_sys_openat fs/open.c:1236 [inline] __se_sys_openat fs/open.c:1231 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1231 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+0x44/0xae RIP: 0033:0x4af20a Code: e8 3b 82 fb ff 48 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 4c 8b 54 24 28 4c 8b 44 24 30 4c 8b 4c 24 38 48 8b 44 24 08 0f 05 <48> 3d 01 f0 ff ff 76 20 48 c7 44 24 40 ff ff ff ff 48 c7 44 24 48 RSP: 002b:000000c00036f3f8 EFLAGS: 00000216 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 000000c00001c000 RCX: 00000000004af20a RDX: 0000000000000000 RSI: 000000c000167a70 RDI: ffffffffffffff9c RBP: 000000c00036f470 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000216 R12: 00000000000001a8 R13: 00000000000001a7 R14: 0000000000000200 R15: 000000c0004a9180 can: request_module (can-proto-0) failed. can: request_module (can-proto-0) failed. can: request_module (can-proto-0) failed. base_sock_release(ffff8880223a5a00) sk=ffff888022d04000 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