======================================================== WARNING: possible irq lock inversion dependency detected 5.7.0-rc1-next-20200415-syzkaller #0 Not tainted -------------------------------------------------------- syz-executor.0/11654 just changed the state of lock: ffff88804e60a398 (&info->lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:353 [inline] ffff88804e60a398 (&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.0/11654: #0: ffff88808c49a568 (&mm->mmap_sem#2){++++}-{3:3}, at: __mcopy_atomic mm/userfaultfd.c:491 [inline] #0: ffff88808c49a568 (&mm->mmap_sem#2){++++}-{3:3}, at: mcopy_atomic+0x195/0x2630 mm/userfaultfd.c:632 #1: ffff8880a142b4f8 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:353 [inline] #1: ffff8880a142b4f8 (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: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 core_kernel_text kernel/extable.c:75 [inline] kernel_text_address+0x11/0xe0 kernel/extable.c:125 __kernel_text_address+0x9/0x30 kernel/extable.c:105 unwind_get_return_address arch/x86/kernel/unwind_orc.c:314 [inline] unwind_get_return_address+0x5a/0xa0 arch/x86/kernel/unwind_orc.c:309 arch_stack_walk+0x84/0xd0 arch/x86/kernel/stacktrace.c:26 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] __do_kmalloc mm/slab.c:3654 [inline] __kmalloc+0x14b/0x7a0 mm/slab.c:3665 kmalloc include/linux/slab.h:560 [inline] tomoyo_realpath_from_path+0xc2/0x620 security/tomoyo/realpath.c:252 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x214/0x400 security/tomoyo/file.c:822 security_inode_getattr+0xeb/0x150 security/security.c:1273 vfs_getattr+0x22/0x60 fs/stat.c:117 vfs_statx_fd+0x6a/0xb0 fs/stat.c:147 vfs_fstat include/linux/fs.h:3295 [inline] __do_sys_newfstat+0x8b/0x100 fs/stat.c:388 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] __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: __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_fallocate+0xbe2/0xd40 mm/shmem.c:2810 vfs_fallocate+0x48a/0xa10 fs/open.c:309 ksys_fallocate+0x51/0x90 fs/open.c:332 __do_sys_fallocate fs/open.c:340 [inline] __se_sys_fallocate fs/open.c:338 [inline] __x64_sys_fallocate+0x93/0xf0 fs/open.c:338 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: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: 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+0x98c/0x4c50 kernel/locking/lockdep.c:4309 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 stack backtrace: CPU: 0 PID: 11654 Comm: syz-executor.0 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_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+0x98c/0x4c50 kernel/locking/lockdep.c:4309 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 RIP: 0033:0x45c829 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:00007f90aff94c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004ef800 RCX: 000000000045c829 RDX: 00000000200a0fe0 RSI: 00000000c028aa03 RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000005b5 R14: 00000000004c8527 R15: 00007f90aff956d4