======================================================== WARNING: possible irq lock inversion dependency detected 5.6.0-syzkaller #0 Not tainted -------------------------------------------------------- syz-executor.2/22536 just changed the state of lock: ffffffff89315258 (shmlock_user_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:353 [inline] ffffffff89315258 (shmlock_user_lock){+.+.}-{2:2}, at: user_shm_lock+0x8b/0x1a0 mm/mlock.c:855 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: Chain exists of: &xa->xa_lock#4 --> &info->lock --> shmlock_user_lock Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(shmlock_user_lock); local_irq_disable(); lock(&xa->xa_lock#4); lock(&info->lock); lock(&xa->xa_lock#4); *** DEADLOCK *** 1 lock held by syz-executor.2/22536: #0: ffff888053b4a550 (&ids->rwsem){++++}-{3:3}, at: ipcget_new ipc/util.c:343 [inline] #0: ffff888053b4a550 (&ids->rwsem){++++}-{3:3}, at: ipcget+0x127/0xb30 ipc/util.c:643 the shortest dependencies between 2nd lock and 1st lock: -> (&xa->xa_lock#4){..-.}-{2:2} { IN-SOFTIRQ-W at: lock_acquire+0x169/0x480 kernel/locking/lockdep.c:4923 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x9e/0xc0 kernel/locking/spinlock.c:159 test_clear_page_writeback+0x2d8/0xac0 mm/page-writeback.c:2728 end_page_writeback+0x212/0x390 mm/filemap.c:1317 end_bio_bh_io_sync+0xb1/0x110 fs/buffer.c:3012 req_bio_endio block/blk-core.c:245 [inline] blk_update_request+0x437/0x1070 block/blk-core.c:1472 scsi_end_request+0x7a/0x7f0 drivers/scsi/scsi_lib.c:575 scsi_io_completion+0x178/0x1be0 drivers/scsi/scsi_lib.c:959 blk_done_softirq+0x2f2/0x360 block/blk-softirq.c:37 __do_softirq+0x268/0x80c kernel/softirq.c:292 run_ksoftirqd+0x60/0xf0 kernel/softirq.c:604 smpboot_thread_fn+0x572/0x970 kernel/smpboot.c:165 kthread+0x353/0x380 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INITIAL USE at: lock_acquire+0x169/0x480 kernel/locking/lockdep.c:4923 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x67/0x80 kernel/locking/spinlock.c:167 spin_lock_irq include/linux/spinlock.h:378 [inline] __add_to_page_cache_locked+0x53d/0xc70 mm/filemap.c:855 add_to_page_cache_lru+0x17f/0x4d0 mm/filemap.c:921 do_read_cache_page+0x209/0xd00 mm/filemap.c:2755 read_mapping_page include/linux/pagemap.h:397 [inline] read_part_sector+0xd8/0x2d0 block/partitions/core.c:643 adfspart_check_ICS+0x45/0x640 block/partitions/acorn.c:360 check_partition block/partitions/core.c:140 [inline] blk_add_partitions+0x3ce/0x1240 block/partitions/core.c:571 bdev_disk_changed+0x446/0x5d0 fs/block_dev.c:1544 __blkdev_get+0xb2b/0x13d0 fs/block_dev.c:1647 register_disk block/genhd.c:763 [inline] __device_add_disk+0x95f/0x1040 block/genhd.c:853 add_disk include/linux/genhd.h:294 [inline] brd_init+0x349/0x42a drivers/block/brd.c:533 do_one_initcall+0x14b/0x350 init/main.c:1158 do_initcall_level+0x101/0x14c init/main.c:1231 do_initcalls+0x59/0x9b init/main.c:1247 kernel_init_freeable+0x2fa/0x418 init/main.c:1451 kernel_init+0xd/0x290 init/main.c:1358 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 } ... key at: [] xa_init_flags.__key+0x0/0x10 ... acquired at: lock_acquire+0x169/0x480 kernel/locking/lockdep.c:4923 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x9e/0xc0 kernel/locking/spinlock.c:159 shmem_uncharge+0x34/0x4c0 mm/shmem.c:341 __split_huge_page+0xda8/0x1900 mm/huge_memory.c:2613 split_huge_page_to_list+0x10a4/0x15f0 mm/huge_memory.c:2886 split_huge_page include/linux/huge_mm.h:204 [inline] shmem_punch_compound+0x17d/0x1c0 mm/shmem.c:814 shmem_undo_range+0x5da/0x1d00 mm/shmem.c:870 shmem_truncate_range mm/shmem.c:980 [inline] shmem_setattr+0x4e3/0x8a0 mm/shmem.c:1039 notify_change+0xad5/0xfb0 fs/attr.c:336 do_truncate fs/open.c:64 [inline] do_sys_ftruncate+0x55f/0x690 fs/open.c:195 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 -> (&info->lock){....}-{2:2} { INITIAL USE at: lock_acquire+0x169/0x480 kernel/locking/lockdep.c:4923 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x67/0x80 kernel/locking/spinlock.c:167 spin_lock_irq include/linux/spinlock.h:378 [inline] shmem_getpage_gfp+0x2160/0x3120 mm/shmem.c:1882 shmem_getpage mm/shmem.c:154 [inline] shmem_write_begin+0xcd/0x1a0 mm/shmem.c:2483 generic_perform_write+0x23b/0x4e0 mm/filemap.c:3302 __generic_file_write_iter+0x22b/0x4e0 mm/filemap.c:3431 generic_file_write_iter+0x4a6/0x650 mm/filemap.c:3463 call_write_iter include/linux/fs.h:1907 [inline] new_sync_write fs/read_write.c:483 [inline] __vfs_write+0x54c/0x710 fs/read_write.c:496 vfs_write+0x274/0x580 fs/read_write.c:558 ksys_write+0x11b/0x220 fs/read_write.c:611 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 } ... key at: [] shmem_get_inode.__key+0x0/0x10 ... acquired at: lock_acquire+0x169/0x480 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] user_shm_lock+0x8b/0x1a0 mm/mlock.c:855 shmem_lock+0xd1/0x210 mm/shmem.c:2184 shmctl_do_lock+0x425/0x790 ipc/shm.c:1111 ksys_shmctl ipc/shm.c:1188 [inline] __do_sys_shmctl ipc/shm.c:1196 [inline] __se_sys_shmctl+0x1b9/0x500 ipc/shm.c:1194 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 -> (shmlock_user_lock){+.+.}-{2:2} { HARDIRQ-ON-W at: lock_acquire+0x169/0x480 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] user_shm_lock+0x8b/0x1a0 mm/mlock.c:855 hugetlb_file_setup+0x257/0x590 fs/hugetlbfs/inode.c:1416 newseg+0x44e/0xc40 ipc/shm.c:652 ipcget_new ipc/util.c:344 [inline] ipcget+0x14c/0xb30 ipc/util.c:643 ksys_shmget ipc/shm.c:742 [inline] __do_sys_shmget ipc/shm.c:747 [inline] __se_sys_shmget ipc/shm.c:745 [inline] __x64_sys_shmget+0x125/0x170 ipc/shm.c:745 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 SOFTIRQ-ON-W at: lock_acquire+0x169/0x480 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] user_shm_lock+0x8b/0x1a0 mm/mlock.c:855 hugetlb_file_setup+0x257/0x590 fs/hugetlbfs/inode.c:1416 newseg+0x44e/0xc40 ipc/shm.c:652 ipcget_new ipc/util.c:344 [inline] ipcget+0x14c/0xb30 ipc/util.c:643 ksys_shmget ipc/shm.c:742 [inline] __do_sys_shmget ipc/shm.c:747 [inline] __se_sys_shmget ipc/shm.c:745 [inline] __x64_sys_shmget+0x125/0x170 ipc/shm.c:745 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 INITIAL USE at: lock_acquire+0x169/0x480 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] user_shm_lock+0x8b/0x1a0 mm/mlock.c:855 shmem_lock+0xd1/0x210 mm/shmem.c:2184 shmctl_do_lock+0x425/0x790 ipc/shm.c:1111 ksys_shmctl ipc/shm.c:1188 [inline] __do_sys_shmctl ipc/shm.c:1196 [inline] __se_sys_shmctl+0x1b9/0x500 ipc/shm.c:1194 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 } ... key at: [] shmlock_user_lock+0x18/0x40 ... acquired at: mark_lock_irq kernel/locking/lockdep.c:3585 [inline] mark_lock+0x529/0x1b00 kernel/locking/lockdep.c:3935 mark_usage kernel/locking/lockdep.c:3852 [inline] __lock_acquire+0xb95/0x2b90 kernel/locking/lockdep.c:4298 lock_acquire+0x169/0x480 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] user_shm_lock+0x8b/0x1a0 mm/mlock.c:855 hugetlb_file_setup+0x257/0x590 fs/hugetlbfs/inode.c:1416 newseg+0x44e/0xc40 ipc/shm.c:652 ipcget_new ipc/util.c:344 [inline] ipcget+0x14c/0xb30 ipc/util.c:643 ksys_shmget ipc/shm.c:742 [inline] __do_sys_shmget ipc/shm.c:747 [inline] __se_sys_shmget ipc/shm.c:745 [inline] __x64_sys_shmget+0x125/0x170 ipc/shm.c:745 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 stack backtrace: CPU: 1 PID: 22536 Comm: syz-executor.2 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+0x1e9/0x30e lib/dump_stack.c:118 print_irq_inversion_bug+0xb67/0xe90 kernel/locking/lockdep.c:3447 check_usage_backwards+0x13f/0x240 kernel/locking/lockdep.c:3499 mark_lock_irq kernel/locking/lockdep.c:3585 [inline] mark_lock+0x529/0x1b00 kernel/locking/lockdep.c:3935 mark_usage kernel/locking/lockdep.c:3852 [inline] __lock_acquire+0xb95/0x2b90 kernel/locking/lockdep.c:4298 lock_acquire+0x169/0x480 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] user_shm_lock+0x8b/0x1a0 mm/mlock.c:855 hugetlb_file_setup+0x257/0x590 fs/hugetlbfs/inode.c:1416 newseg+0x44e/0xc40 ipc/shm.c:652 ipcget_new ipc/util.c:344 [inline] ipcget+0x14c/0xb30 ipc/util.c:643 ksys_shmget ipc/shm.c:742 [inline] __do_sys_shmget ipc/shm.c:747 [inline] __se_sys_shmget ipc/shm.c:745 [inline] __x64_sys_shmget+0x125/0x170 ipc/shm.c:745 do_syscall_64+0xf3/0x1b0 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:00007f2bb9618c78 EFLAGS: 00000246 ORIG_RAX: 000000000000001d RAX: ffffffffffffffda RBX: 00007f2bb96196d4 RCX: 000000000045c889 RDX: 0000000078000e02 RSI: 0000000000003000 RDI: 0400000000000000 RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000020ff4000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000b5d R14: 00000000004cd951 R15: 000000000076bf0c