===================================================== WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected 5.7.0-rc1-next-20200415-syzkaller #0 Not tainted ----------------------------------------------------- syz-executor.1/3104 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: ffff88809f016e58 (&info->lock){+.+.}-{2:2}, at: shmem_uncharge+0x24/0x270 mm/shmem.c:341 and this task is already holding: ffff88809f0171a8 (&xa->xa_lock#4){..-.}-{2:2}, at: spin_lock include/linux/spinlock.h:353 [inline] ffff88809f0171a8 (&xa->xa_lock#4){..-.}-{2:2}, at: split_huge_page_to_list+0xad0/0x33b0 mm/huge_memory.c:2864 which would create a new lock dependency: (&xa->xa_lock#4){..-.}-{2:2} -> (&info->lock){+.+.}-{2:2} but this new dependency connects a SOFTIRQ-irq-safe lock: (&xa->xa_lock#4){..-.}-{2:2} ... which became SOFTIRQ-irq-safe at: lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xbf kernel/locking/spinlock.c:159 test_clear_page_writeback+0x1d7/0x11e0 mm/page-writeback.c:2728 end_page_writeback+0x239/0x520 mm/filemap.c:1317 end_buffer_async_write+0x442/0x5c0 fs/buffer.c:384 end_bio_bh_io_sync+0xe2/0x140 fs/buffer.c:3049 bio_endio+0x46a/0x820 block/bio.c:1422 req_bio_endio block/blk-core.c:245 [inline] blk_update_request+0x3e1/0xdc0 block/blk-core.c:1472 scsi_end_request+0x80/0x7b0 drivers/scsi/scsi_lib.c:575 scsi_io_completion+0x1e7/0x1300 drivers/scsi/scsi_lib.c:959 scsi_softirq_done+0x31e/0x3b0 drivers/scsi/scsi_lib.c:1454 blk_done_softirq+0x2db/0x440 block/blk-softirq.c:37 __do_softirq+0x26c/0x9f7 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x192/0x1d0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:546 [inline] do_IRQ+0xda/0x270 arch/x86/kernel/irq.c:263 ret_from_intr+0x0/0x2b __read_once_size include/linux/compiler.h:232 [inline] PageTail include/linux/page-flags.h:191 [inline] __page_cache_add_speculative include/linux/pagemap.h:193 [inline] page_cache_get_speculative include/linux/pagemap.h:200 [inline] find_get_pages_range_tag+0x2a9/0xbf0 mm/filemap.c:1922 pagevec_lookup_range_tag+0x3b/0x80 mm/swap.c:1079 write_cache_pages+0x21d/0x12f0 mm/page-writeback.c:2195 generic_writepages mm/page-writeback.c:2329 [inline] generic_writepages+0xed/0x160 mm/page-writeback.c:2318 do_writepages+0xfa/0x2a0 mm/page-writeback.c:2344 __writeback_single_inode+0x12a/0x1410 fs/fs-writeback.c:1452 writeback_sb_inodes+0x515/0xdd0 fs/fs-writeback.c:1716 __writeback_inodes_wb+0xc3/0x250 fs/fs-writeback.c:1785 wb_writeback+0x910/0xd90 fs/fs-writeback.c:1894 wb_check_background_flush fs/fs-writeback.c:1962 [inline] wb_do_writeback fs/fs-writeback.c:2050 [inline] wb_workfn+0xa49/0x11c0 fs/fs-writeback.c:2078 process_one_work+0x965/0x16a0 kernel/workqueue.c:2268 worker_thread+0x96/0xe20 kernel/workqueue.c:2414 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 to a SOFTIRQ-irq-unsafe lock: (&info->lock){+.+.}-{2:2} ... which became SOFTIRQ-irq-unsafe at: ... lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:353 [inline] shmem_mfill_atomic_pte+0x1012/0x21c0 mm/shmem.c:2402 shmem_mcopy_atomic_pte+0x3a/0x50 mm/shmem.c:2440 mfill_atomic_pte mm/userfaultfd.c:449 [inline] __mcopy_atomic mm/userfaultfd.c:582 [inline] mcopy_atomic+0xb31/0x2630 mm/userfaultfd.c:632 userfaultfd_copy fs/userfaultfd.c:1743 [inline] userfaultfd_ioctl+0x752/0x4210 fs/userfaultfd.c:1941 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:770 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&info->lock); local_irq_disable(); lock(&xa->xa_lock#4); lock(&info->lock); lock(&xa->xa_lock#4); *** DEADLOCK *** 5 locks held by syz-executor.1/3104: #0: ffff88804999e450 (sb_writers#7){.+.+}-{0:0}, at: sb_start_write include/linux/fs.h:1655 [inline] #0: ffff88804999e450 (sb_writers#7){.+.+}-{0:0}, at: mnt_want_write+0x3a/0xb0 fs/namespace.c:354 #1: ffff88809f0170b0 (&sb->s_type->i_mutex_key#16){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:797 [inline] #1: ffff88809f0170b0 (&sb->s_type->i_mutex_key#16){+.+.}-{3:3}, at: do_truncate+0x125/0x1f0 fs/open.c:62 #2: ffff88809f017270 (&mapping->i_mmap_rwsem){++++}-{3:3}, at: i_mmap_lock_read include/linux/fs.h:541 [inline] #2: ffff88809f017270 (&mapping->i_mmap_rwsem){++++}-{3:3}, at: split_huge_page_to_list+0x4c3/0x33b0 mm/huge_memory.c:2825 #3: ffff88812ffffcd8 (&pgdat->lru_lock){..-.}-{2:2}, at: split_huge_page_to_list+0x8da/0x33b0 mm/huge_memory.c:2855 #4: ffff88809f0171a8 (&xa->xa_lock#4){..-.}-{2:2}, at: spin_lock include/linux/spinlock.h:353 [inline] #4: ffff88809f0171a8 (&xa->xa_lock#4){..-.}-{2:2}, at: split_huge_page_to_list+0xad0/0x33b0 mm/huge_memory.c:2864 the dependencies between SOFTIRQ-irq-safe lock and the holding lock: -> (&xa->xa_lock#4){..-.}-{2:2} { IN-SOFTIRQ-W at: lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xbf kernel/locking/spinlock.c:159 test_clear_page_writeback+0x1d7/0x11e0 mm/page-writeback.c:2728 end_page_writeback+0x239/0x520 mm/filemap.c:1317 end_buffer_async_write+0x442/0x5c0 fs/buffer.c:384 end_bio_bh_io_sync+0xe2/0x140 fs/buffer.c:3049 bio_endio+0x46a/0x820 block/bio.c:1422 req_bio_endio block/blk-core.c:245 [inline] blk_update_request+0x3e1/0xdc0 block/blk-core.c:1472 scsi_end_request+0x80/0x7b0 drivers/scsi/scsi_lib.c:575 scsi_io_completion+0x1e7/0x1300 drivers/scsi/scsi_lib.c:959 scsi_softirq_done+0x31e/0x3b0 drivers/scsi/scsi_lib.c:1454 blk_done_softirq+0x2db/0x440 block/blk-softirq.c:37 __do_softirq+0x26c/0x9f7 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x192/0x1d0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:546 [inline] do_IRQ+0xda/0x270 arch/x86/kernel/irq.c:263 ret_from_intr+0x0/0x2b __read_once_size include/linux/compiler.h:232 [inline] PageTail include/linux/page-flags.h:191 [inline] __page_cache_add_speculative include/linux/pagemap.h:193 [inline] page_cache_get_speculative include/linux/pagemap.h:200 [inline] find_get_pages_range_tag+0x2a9/0xbf0 mm/filemap.c:1922 pagevec_lookup_range_tag+0x3b/0x80 mm/swap.c:1079 write_cache_pages+0x21d/0x12f0 mm/page-writeback.c:2195 generic_writepages mm/page-writeback.c:2329 [inline] generic_writepages+0xed/0x160 mm/page-writeback.c:2318 do_writepages+0xfa/0x2a0 mm/page-writeback.c:2344 __writeback_single_inode+0x12a/0x1410 fs/fs-writeback.c:1452 writeback_sb_inodes+0x515/0xdd0 fs/fs-writeback.c:1716 __writeback_inodes_wb+0xc3/0x250 fs/fs-writeback.c:1785 wb_writeback+0x910/0xd90 fs/fs-writeback.c:1894 wb_check_background_flush fs/fs-writeback.c:1962 [inline] wb_do_writeback fs/fs-writeback.c:2050 [inline] wb_workfn+0xa49/0x11c0 fs/fs-writeback.c:2078 process_one_work+0x965/0x16a0 kernel/workqueue.c:2268 worker_thread+0x96/0xe20 kernel/workqueue.c:2414 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INITIAL USE at: lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x5b/0x80 kernel/locking/spinlock.c:167 spin_lock_irq include/linux/spinlock.h:378 [inline] __add_to_page_cache_locked+0x607/0xe00 mm/filemap.c:855 add_to_page_cache_lru+0x1aa/0x700 mm/filemap.c:921 do_read_cache_page+0x9ab/0x1810 mm/filemap.c:2761 read_mapping_page include/linux/pagemap.h:397 [inline] read_part_sector+0xf6/0x600 block/partitions/core.c:643 adfspart_check_ICS+0x9d/0xc80 block/partitions/acorn.c:360 check_partition block/partitions/core.c:140 [inline] blk_add_partitions+0x474/0xe50 block/partitions/core.c:571 bdev_disk_changed+0x1fb/0x380 fs/block_dev.c:1544 __blkdev_get+0xb15/0x1530 fs/block_dev.c:1647 blkdev_get+0x41/0x2b0 fs/block_dev.c:1749 register_disk block/genhd.c:763 [inline] __device_add_disk+0xa4f/0x1170 block/genhd.c:853 add_disk include/linux/genhd.h:294 [inline] brd_init+0x297/0x463 drivers/block/brd.c:533 do_one_initcall+0x10a/0x7d0 init/main.c:1160 do_initcall_level init/main.c:1233 [inline] do_initcalls init/main.c:1249 [inline] do_basic_setup init/main.c:1269 [inline] kernel_init_freeable+0x501/0x5ae init/main.c:1454 kernel_init+0xd/0x1bb init/main.c:1360 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 } ... key at: [] __key.18068+0x0/0x40 ... acquired at: lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xbf kernel/locking/spinlock.c:159 shmem_uncharge+0x24/0x270 mm/shmem.c:341 __split_huge_page mm/huge_memory.c:2613 [inline] split_huge_page_to_list+0x274b/0x33b0 mm/huge_memory.c:2886 split_huge_page include/linux/huge_mm.h:204 [inline] shmem_punch_compound+0x13e/0x1e0 mm/shmem.c:814 shmem_undo_range+0x5f1/0x1b80 mm/shmem.c:870 shmem_truncate_range+0x27/0xa0 mm/shmem.c:980 shmem_setattr+0x8b6/0xc80 mm/shmem.c:1039 notify_change+0xb6d/0x1020 fs/attr.c:336 do_truncate+0x134/0x1f0 fs/open.c:64 vfs_truncate+0x559/0x6e0 fs/open.c:110 do_sys_truncate.part.0+0x11e/0x140 fs/open.c:133 do_sys_truncate fs/open.c:127 [inline] __do_sys_truncate fs/open.c:145 [inline] __se_sys_truncate fs/open.c:143 [inline] __x64_sys_truncate+0x69/0x90 fs/open.c:143 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 the dependencies between the lock to be acquired and SOFTIRQ-irq-unsafe lock: -> (&info->lock){+.+.}-{2:2} { HARDIRQ-ON-W at: lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:353 [inline] shmem_mfill_atomic_pte+0x1012/0x21c0 mm/shmem.c:2402 shmem_mcopy_atomic_pte+0x3a/0x50 mm/shmem.c:2440 mfill_atomic_pte mm/userfaultfd.c:449 [inline] __mcopy_atomic mm/userfaultfd.c:582 [inline] mcopy_atomic+0xb31/0x2630 mm/userfaultfd.c:632 userfaultfd_copy fs/userfaultfd.c:1743 [inline] userfaultfd_ioctl+0x752/0x4210 fs/userfaultfd.c:1941 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:770 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 SOFTIRQ-ON-W at: lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:353 [inline] shmem_mfill_atomic_pte+0x1012/0x21c0 mm/shmem.c:2402 shmem_mcopy_atomic_pte+0x3a/0x50 mm/shmem.c:2440 mfill_atomic_pte mm/userfaultfd.c:449 [inline] __mcopy_atomic mm/userfaultfd.c:582 [inline] mcopy_atomic+0xb31/0x2630 mm/userfaultfd.c:632 userfaultfd_copy fs/userfaultfd.c:1743 [inline] userfaultfd_ioctl+0x752/0x4210 fs/userfaultfd.c:1941 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:770 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 INITIAL USE at: lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x5b/0x80 kernel/locking/spinlock.c:167 spin_lock_irq include/linux/spinlock.h:378 [inline] shmem_getpage_gfp+0x937/0x2a10 mm/shmem.c:1882 shmem_getpage mm/shmem.c:154 [inline] shmem_write_begin+0x102/0x1e0 mm/shmem.c:2483 generic_perform_write+0x20a/0x4e0 mm/filemap.c:3308 __generic_file_write_iter+0x24c/0x610 mm/filemap.c:3437 generic_file_write_iter+0x3f3/0x630 mm/filemap.c:3469 call_write_iter include/linux/fs.h:1907 [inline] new_sync_write+0x4a2/0x700 fs/read_write.c:484 __vfs_write+0xc9/0x100 fs/read_write.c:497 vfs_write+0x268/0x5d0 fs/read_write.c:559 ksys_write+0x12d/0x250 fs/read_write.c:612 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 } ... key at: [] __key.56628+0x0/0x40 ... acquired at: lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xbf kernel/locking/spinlock.c:159 shmem_uncharge+0x24/0x270 mm/shmem.c:341 __split_huge_page mm/huge_memory.c:2613 [inline] split_huge_page_to_list+0x274b/0x33b0 mm/huge_memory.c:2886 split_huge_page include/linux/huge_mm.h:204 [inline] shmem_punch_compound+0x13e/0x1e0 mm/shmem.c:814 shmem_undo_range+0x5f1/0x1b80 mm/shmem.c:870 shmem_truncate_range+0x27/0xa0 mm/shmem.c:980 shmem_setattr+0x8b6/0xc80 mm/shmem.c:1039 notify_change+0xb6d/0x1020 fs/attr.c:336 do_truncate+0x134/0x1f0 fs/open.c:64 vfs_truncate+0x559/0x6e0 fs/open.c:110 do_sys_truncate.part.0+0x11e/0x140 fs/open.c:133 do_sys_truncate fs/open.c:127 [inline] __do_sys_truncate fs/open.c:145 [inline] __se_sys_truncate fs/open.c:143 [inline] __x64_sys_truncate+0x69/0x90 fs/open.c:143 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 stack backtrace: CPU: 1 PID: 3104 Comm: syz-executor.1 Not tainted 5.7.0-rc1-next-20200415-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+0x188/0x20d lib/dump_stack.c:118 print_bad_irq_dependency kernel/locking/lockdep.c:2132 [inline] check_irq_usage.cold+0x566/0x6de kernel/locking/lockdep.c:2330 check_prev_add kernel/locking/lockdep.c:2519 [inline] check_prevs_add kernel/locking/lockdep.c:2620 [inline] validate_chain kernel/locking/lockdep.c:3237 [inline] __lock_acquire+0x2ac9/0x4c50 kernel/locking/lockdep.c:4355 lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xbf kernel/locking/spinlock.c:159 shmem_uncharge+0x24/0x270 mm/shmem.c:341 __split_huge_page mm/huge_memory.c:2613 [inline] split_huge_page_to_list+0x274b/0x33b0 mm/huge_memory.c:2886 split_huge_page include/linux/huge_mm.h:204 [inline] shmem_punch_compound+0x13e/0x1e0 mm/shmem.c:814 shmem_undo_range+0x5f1/0x1b80 mm/shmem.c:870 shmem_truncate_range+0x27/0xa0 mm/shmem.c:980 shmem_setattr+0x8b6/0xc80 mm/shmem.c:1039 notify_change+0xb6d/0x1020 fs/attr.c:336 do_truncate+0x134/0x1f0 fs/open.c:64 vfs_truncate+0x559/0x6e0 fs/open.c:110 do_sys_truncate.part.0+0x11e/0x140 fs/open.c:133 do_sys_truncate fs/open.c:127 [inline] __do_sys_truncate fs/open.c:145 [inline] __se_sys_truncate fs/open.c:143 [inline] __x64_sys_truncate+0x69/0x90 fs/open.c:143 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca29 Code: 0d b7 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 b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007efd22a55c78 EFLAGS: 00000246 ORIG_RAX: 000000000000004c RAX: ffffffffffffffda RBX: 000000000050a080 RCX: 000000000045ca29 RDX: 0000000000000000 RSI: 0000000000000101 RDI: 0000000020000180 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000c49 R14: 00000000004c3902 R15: 00007efd22a566d4