======================================================== WARNING: possible irq lock inversion dependency detected 5.6.0-syzkaller #0 Not tainted -------------------------------------------------------- syz-executor.1/30465 just changed the state of lock: ffff8880573ee6b8 (&info->lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:353 [inline] ffff8880573ee6b8 (&info->lock){+.+.}-{2:2}, at: shmem_mfill_atomic_pte+0x1012/0x21c0 mm/shmem.c:2402 but this lock was taken by another, SOFTIRQ-safe lock in the past: (&xa->xa_lock#4){..-.}-{2:2} and interrupts could create inverse lock ordering between them. 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 *** 2 locks held by syz-executor.1/30465: #0: ffff88804f5f6ea8 (&mm->mmap_sem#2){++++}-{3:3}, at: __mcopy_atomic mm/userfaultfd.c:491 [inline] #0: ffff88804f5f6ea8 (&mm->mmap_sem#2){++++}-{3:3}, at: mcopy_atomic+0x195/0x2630 mm/userfaultfd.c:632 #1: ffff888098ed1078 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:353 [inline] #1: ffff888098ed1078 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: shmem_mfill_atomic_pte+0xf76/0x21c0 mm/shmem.c:2389 the shortest dependencies between 2nd lock and 1st lock: -> (&xa->xa_lock#4){..-.}-{2:2} { IN-SOFTIRQ-W at: lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4923 __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:3012 bio_endio+0x473/0x820 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 __preempt_count_sub arch/x86/include/asm/preempt.h:84 [inline] preempt_count_sub+0x5f/0x150 kernel/sched/core.c:3833 unwind_next_frame+0xdba/0x19d0 arch/x86/kernel/unwind_orc.c:572 arch_stack_walk+0x74/0xd0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:123 save_stack+0x1b/0x40 mm/kasan/common.c:49 set_track mm/kasan/common.c:57 [inline] __kasan_kmalloc mm/kasan/common.c:495 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:468 slab_post_alloc_hook mm/slab.h:586 [inline] slab_alloc mm/slab.c:3320 [inline] kmem_cache_alloc+0x11b/0x740 mm/slab.c:3484 mempool_alloc+0x148/0x340 mm/mempool.c:393 bio_alloc_bioset+0x384/0x600 block/bio.c:481 bio_alloc include/linux/bio.h:400 [inline] submit_bh_wbc+0x1bb/0x8e0 fs/buffer.c:3037 __block_write_full_page+0x800/0x1280 fs/buffer.c:1801 block_write_full_page+0x21a/0x270 fs/buffer.c:2987 __writepage+0x62/0x100 mm/page-writeback.c:2303 write_cache_pages+0x799/0x12f0 mm/page-writeback.c:2238 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:2266 worker_thread+0x96/0xe20 kernel/workqueue.c:2412 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:4923 __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:2755 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:1157 do_initcall_level init/main.c:1230 [inline] do_initcalls init/main.c:1246 [inline] do_basic_setup init/main.c:1266 [inline] kernel_init_freeable+0x501/0x5ae init/main.c:1450 kernel_init+0xd/0x1bb init/main.c:1357 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 } ... key at: [] __key.18006+0x0/0x40 ... acquired at: __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+0x99c/0xc80 mm/shmem.c:1039 notify_change+0xb6d/0x1020 fs/attr.c:336 do_truncate+0x134/0x1f0 fs/open.c:64 do_sys_ftruncate+0x4a5/0x570 fs/open.c:195 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 -> (&info->lock){+.+.}-{2:2} { HARDIRQ-ON-W at: lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4923 __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+0x748/0x42a0 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:4923 __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+0x748/0x42a0 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:4923 __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:3302 __generic_file_write_iter+0x24c/0x610 mm/filemap.c:3431 generic_file_write_iter+0x3f3/0x630 mm/filemap.c:3463 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.56444+0x0/0x40 ... acquired at: mark_lock_irq kernel/locking/lockdep.c:3585 [inline] mark_lock+0x624/0xf10 kernel/locking/lockdep.c:3935 mark_usage kernel/locking/lockdep.c:3852 [inline] __lock_acquire+0x990/0x4e00 kernel/locking/lockdep.c:4298 lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4923 __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+0x748/0x42a0 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 stack backtrace: CPU: 1 PID: 30465 Comm: syz-executor.1 Not tainted 5.6.0-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_irq_inversion_bug kernel/locking/lockdep.c:3448 [inline] check_usage_backwards.cold+0x1d/0x26 kernel/locking/lockdep.c:3499 mark_lock_irq kernel/locking/lockdep.c:3585 [inline] mark_lock+0x624/0xf10 kernel/locking/lockdep.c:3935 mark_usage kernel/locking/lockdep.c:3852 [inline] __lock_acquire+0x990/0x4e00 kernel/locking/lockdep.c:4298 lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4923 __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+0x748/0x42a0 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 RIP: 0033:0x45c889 Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fa025c9cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fa025c9d6d4 RCX: 000000000045c889 RDX: 00000000200a0fe0 RSI: 00000000c028aa03 RDI: 0000000000000003 RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000005b3 R14: 00000000004c854c R15: 000000000076bf0c