======================================================== WARNING: possible irq lock inversion dependency detected 5.6.0-syzkaller #0 Not tainted -------------------------------------------------------- syz-executor.3/8472 just changed the state of lock: ffff88809711b238 (&info->lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:353 [inline] ffff88809711b238 (&info->lock){+.+.}-{2:2}, at: shmem_mfill_atomic_pte+0xc21/0x19c0 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.3/8472: #0: ffff888099ca3a28 (&mm->mmap_sem#2){++++}-{3:3}, at: __mcopy_atomic mm/userfaultfd.c:491 [inline] #0: ffff888099ca3a28 (&mm->mmap_sem#2){++++}-{3:3}, at: mcopy_atomic+0x131/0x2050 mm/userfaultfd.c:632 #1: ffff8880a0ff0d38 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:353 [inline] #1: ffff8880a0ff0d38 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: shmem_mfill_atomic_pte+0xbaf/0x19c0 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+0x1e3/0x970 kernel/locking/lockdep.c:4923 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x95/0xc0 kernel/locking/spinlock.c:159 test_clear_page_writeback+0x18f/0xd50 mm/page-writeback.c:2728 end_page_writeback+0x17d/0x350 mm/filemap.c:1317 end_bio_bh_io_sync+0xb4/0x100 fs/buffer.c:3012 req_bio_endio block/blk-core.c:245 [inline] blk_update_request+0x294/0xa60 block/blk-core.c:1472 scsi_end_request+0x77/0x5e0 drivers/scsi/scsi_lib.c:575 scsi_io_completion+0x1a0/0xfc0 drivers/scsi/scsi_lib.c:959 blk_done_softirq+0x2b1/0x400 block/blk-softirq.c:37 __do_softirq+0x26e/0xa0c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x191/0x1d0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:546 [inline] do_IRQ+0xd9/0x260 arch/x86/kernel/irq.c:263 ret_from_intr+0x0/0x2b arch_local_irq_restore arch/x86/include/asm/paravirt.h:759 [inline] qlink_free mm/kasan/quarantine.c:151 [inline] qlist_free_all+0xe4/0x130 mm/kasan/quarantine.c:167 quarantine_reduce+0x158/0x1a0 mm/kasan/quarantine.c:260 __kasan_kmalloc.constprop.17+0x98/0xd0 mm/kasan/common.c:499 slab_post_alloc_hook mm/slab.h:586 [inline] slab_alloc mm/slab.c:3320 [inline] kmem_cache_alloc+0x11b/0x750 mm/slab.c:3484 getname_flags+0xb5/0x500 fs/namei.c:138 user_path_at_empty+0x18/0x40 fs/namei.c:2632 user_path_at include/linux/namei.h:59 [inline] vfs_statx+0xb5/0x130 fs/stat.c:197 vfs_lstat include/linux/fs.h:3284 [inline] __do_sys_newlstat+0x77/0xd0 fs/stat.c:364 do_syscall_64+0xc6/0x620 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 INITIAL USE at: lock_acquire+0x1e3/0x970 kernel/locking/lockdep.c:4923 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x5e/0x80 kernel/locking/spinlock.c:167 spin_lock_irq include/linux/spinlock.h:378 [inline] __add_to_page_cache_locked+0x4f0/0x9f0 mm/filemap.c:855 add_to_page_cache_lru+0x136/0x490 mm/filemap.c:921 do_read_cache_page+0x2f9/0xaa0 mm/filemap.c:2755 read_mapping_page include/linux/pagemap.h:397 [inline] read_part_sector+0xd8/0x486 block/partitions/core.c:643 adfspart_check_ICS+0x92/0xb30 block/partitions/acorn.c:360 check_partition block/partitions/core.c:140 [inline] blk_add_partitions+0x396/0xc80 block/partitions/core.c:571 bdev_disk_changed+0x175/0x290 fs/block_dev.c:1544 __blkdev_get+0x8dd/0x1180 fs/block_dev.c:1647 register_disk block/genhd.c:763 [inline] __device_add_disk+0xc49/0xf60 block/genhd.c:853 add_disk include/linux/genhd.h:294 [inline] brd_init+0x206/0x392 drivers/block/brd.c:533 do_one_initcall+0xc3/0x580 init/main.c:1158 do_initcall_level init/main.c:1231 [inline] do_initcalls init/main.c:1247 [inline] do_basic_setup init/main.c:1267 [inline] kernel_init_freeable+0x48b/0x4ff init/main.c:1451 kernel_init+0x7/0x102 init/main.c:1358 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 } ... key at: [] __key.18058+0x0/0x40 ... acquired at: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x95/0xc0 kernel/locking/spinlock.c:159 shmem_uncharge+0x1f/0x230 mm/shmem.c:341 __split_huge_page mm/huge_memory.c:2613 [inline] split_huge_page_to_list+0x1b95/0x2690 mm/huge_memory.c:2886 split_huge_page include/linux/huge_mm.h:204 [inline] shmem_punch_compound+0xcf/0x130 mm/shmem.c:814 shmem_undo_range+0x597/0x1370 mm/shmem.c:870 shmem_truncate_range+0xf/0x80 mm/shmem.c:980 shmem_setattr+0x806/0xc20 mm/shmem.c:1039 notify_change+0x72f/0xd00 fs/attr.c:336 do_truncate+0xda/0x180 fs/open.c:64 do_sys_ftruncate+0x325/0x430 fs/open.c:195 do_syscall_64+0xc6/0x620 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 -> (&info->lock){+.+.}-{2:2} { HARDIRQ-ON-W at: lock_acquire+0x1e3/0x970 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+0xc21/0x19c0 mm/shmem.c:2402 shmem_mcopy_atomic_pte+0xa/0x10 mm/shmem.c:2440 mfill_atomic_pte mm/userfaultfd.c:449 [inline] __mcopy_atomic mm/userfaultfd.c:582 [inline] mcopy_atomic+0x7d5/0x2050 mm/userfaultfd.c:632 userfaultfd_copy fs/userfaultfd.c:1743 [inline] userfaultfd_ioctl+0xaf8/0x36a0 fs/userfaultfd.c:1941 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0xb8/0x110 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x6a/0xb0 fs/ioctl.c:770 do_syscall_64+0xc6/0x620 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 SOFTIRQ-ON-W at: lock_acquire+0x1e3/0x970 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+0xc21/0x19c0 mm/shmem.c:2402 shmem_mcopy_atomic_pte+0xa/0x10 mm/shmem.c:2440 mfill_atomic_pte mm/userfaultfd.c:449 [inline] __mcopy_atomic mm/userfaultfd.c:582 [inline] mcopy_atomic+0x7d5/0x2050 mm/userfaultfd.c:632 userfaultfd_copy fs/userfaultfd.c:1743 [inline] userfaultfd_ioctl+0xaf8/0x36a0 fs/userfaultfd.c:1941 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0xb8/0x110 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x6a/0xb0 fs/ioctl.c:770 do_syscall_64+0xc6/0x620 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 INITIAL USE at: lock_acquire+0x1e3/0x970 kernel/locking/lockdep.c:4923 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x5e/0x80 kernel/locking/spinlock.c:167 spin_lock_irq include/linux/spinlock.h:378 [inline] shmem_getpage_gfp+0x946/0x1cb0 mm/shmem.c:1882 shmem_getpage mm/shmem.c:154 [inline] shmem_write_begin+0xcf/0x1b0 mm/shmem.c:2483 generic_perform_write+0x253/0x410 mm/filemap.c:3302 __generic_file_write_iter+0x1ff/0x520 mm/filemap.c:3431 generic_file_write_iter+0x328/0x616 mm/filemap.c:3463 call_write_iter include/linux/fs.h:1907 [inline] new_sync_write+0x417/0x6c0 fs/read_write.c:483 vfs_write+0x18b/0x490 fs/read_write.c:558 ksys_write+0xec/0x1c0 fs/read_write.c:611 do_syscall_64+0xc6/0x620 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 } ... key at: [] __key.56465+0x0/0x40 ... acquired at: mark_lock_irq kernel/locking/lockdep.c:3585 [inline] mark_lock+0x300/0x760 kernel/locking/lockdep.c:3935 mark_usage kernel/locking/lockdep.c:3852 [inline] __lock_acquire+0x9ce/0x3740 kernel/locking/lockdep.c:4298 lock_acquire+0x1e3/0x970 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+0xc21/0x19c0 mm/shmem.c:2402 shmem_mcopy_atomic_pte+0xa/0x10 mm/shmem.c:2440 mfill_atomic_pte mm/userfaultfd.c:449 [inline] __mcopy_atomic mm/userfaultfd.c:582 [inline] mcopy_atomic+0x7d5/0x2050 mm/userfaultfd.c:632 userfaultfd_copy fs/userfaultfd.c:1743 [inline] userfaultfd_ioctl+0xaf8/0x36a0 fs/userfaultfd.c:1941 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0xb8/0x110 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x6a/0xb0 fs/ioctl.c:770 do_syscall_64+0xc6/0x620 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 stack backtrace: CPU: 0 PID: 8472 Comm: syz-executor.3 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+0x128/0x182 lib/dump_stack.c:118 print_irq_inversion_bug kernel/locking/lockdep.c:3448 [inline] check_usage_backwards.cold.61+0x1d/0x26 kernel/locking/lockdep.c:3499 mark_lock_irq kernel/locking/lockdep.c:3585 [inline] mark_lock+0x300/0x760 kernel/locking/lockdep.c:3935 mark_usage kernel/locking/lockdep.c:3852 [inline] __lock_acquire+0x9ce/0x3740 kernel/locking/lockdep.c:4298 lock_acquire+0x1e3/0x970 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+0xc21/0x19c0 mm/shmem.c:2402 shmem_mcopy_atomic_pte+0xa/0x10 mm/shmem.c:2440 mfill_atomic_pte mm/userfaultfd.c:449 [inline] __mcopy_atomic mm/userfaultfd.c:582 [inline] mcopy_atomic+0x7d5/0x2050 mm/userfaultfd.c:632 userfaultfd_copy fs/userfaultfd.c:1743 [inline] userfaultfd_ioctl+0xaf8/0x36a0 fs/userfaultfd.c:1941 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0xb8/0x110 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x6a/0xb0 fs/ioctl.c:770 do_syscall_64+0xc6/0x620 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:00007f5ec1defc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f5ec1df06d4 RCX: 000000000045c889 RDX: 00000000200a0fe0 RSI: 00000000c028aa03 RDI: 0000000000000004 RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000005b3 R14: 00000000004c854c R15: 000000000076bf0c