===================================================== WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected 5.7.0-rc1-next-20200415-syzkaller #0 Not tainted ----------------------------------------------------- syz-executor.0/7433 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: ffff888092ddc938 (&info->lock){....}-{2:2}, at: shmem_uncharge+0x24/0x270 mm/shmem.c:341 and this task is already holding: ffff888092ddcc88 (&xa->xa_lock#4){..-.}-{2:2}, at: spin_lock include/linux/spinlock.h:353 [inline] ffff888092ddcc88 (&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 bytes_is_nonzero mm/kasan/generic.c:92 [inline] memory_is_nonzero mm/kasan/generic.c:109 [inline] memory_is_poisoned_n mm/kasan/generic.c:135 [inline] memory_is_poisoned mm/kasan/generic.c:166 [inline] check_memory_region_inline mm/kasan/generic.c:184 [inline] check_memory_region+0xdf/0x190 mm/kasan/generic.c:193 instrument_atomic_read include/linux/instrumented.h:56 [inline] atomic_read include/asm-generic/atomic-instrumented.h:27 [inline] rcu_dynticks_curr_cpu_in_eqs+0x4f/0xb0 kernel/rcu/tree.c:302 rcu_is_watching+0xc/0x20 kernel/rcu/tree.c:929 rcu_read_lock_held_common+0xaf/0x130 kernel/rcu/update.c:104 rcu_read_lock_held+0x5a/0xb0 kernel/rcu/update.c:305 hlist_bl_first_rcu include/linux/rculist_bl.h:24 [inline] __d_lookup_rcu+0x53a/0x6c0 fs/dcache.c:2244 lookup_fast+0xe0/0x6d0 fs/namei.c:1453 walk_component+0xc6/0x6a0 fs/namei.c:1842 lookup_last fs/namei.c:2295 [inline] path_lookupat.isra.0+0x180/0x530 fs/namei.c:2319 filename_lookup+0x1a3/0x3e0 fs/namei.c:2352 user_path_at include/linux/namei.h:59 [inline] vfs_statx+0x119/0x1e0 fs/stat.c:197 vfs_lstat include/linux/fs.h:3284 [inline] __do_sys_newlstat+0x96/0x120 fs/stat.c:364 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 to a SOFTIRQ-irq-unsafe lock: (shmlock_user_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] user_shm_lock+0xab/0x230 mm/mlock.c:855 hugetlb_file_setup+0x4e1/0x677 fs/hugetlbfs/inode.c:1416 newseg+0x460/0xe60 ipc/shm.c:652 ipcget_new ipc/util.c:344 [inline] ipcget+0xf0/0xcb0 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+0x139/0x1a0 ipc/shm.c:745 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: 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 *** 5 locks held by syz-executor.0/7433: #0: ffff8880a926a450 (sb_writers#7){.+.+}-{0:0}, at: sb_start_write include/linux/fs.h:1655 [inline] #0: ffff8880a926a450 (sb_writers#7){.+.+}-{0:0}, at: do_sys_ftruncate+0x29f/0x570 fs/open.c:190 #1: ffff888092ddcb90 (&sb->s_type->i_mutex_key#16){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:797 [inline] #1: ffff888092ddcb90 (&sb->s_type->i_mutex_key#16){+.+.}-{3:3}, at: do_truncate+0x125/0x1f0 fs/open.c:62 #2: ffff888092ddcd50 (&mapping->i_mmap_rwsem){++++}-{3:3}, at: i_mmap_lock_read include/linux/fs.h:541 [inline] #2: ffff888092ddcd50 (&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: ffff888092ddcc88 (&xa->xa_lock#4){..-.}-{2:2}, at: spin_lock include/linux/spinlock.h:353 [inline] #4: ffff888092ddcc88 (&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 bytes_is_nonzero mm/kasan/generic.c:92 [inline] memory_is_nonzero mm/kasan/generic.c:109 [inline] memory_is_poisoned_n mm/kasan/generic.c:135 [inline] memory_is_poisoned mm/kasan/generic.c:166 [inline] check_memory_region_inline mm/kasan/generic.c:184 [inline] check_memory_region+0xdf/0x190 mm/kasan/generic.c:193 instrument_atomic_read include/linux/instrumented.h:56 [inline] atomic_read include/asm-generic/atomic-instrumented.h:27 [inline] rcu_dynticks_curr_cpu_in_eqs+0x4f/0xb0 kernel/rcu/tree.c:302 rcu_is_watching+0xc/0x20 kernel/rcu/tree.c:929 rcu_read_lock_held_common+0xaf/0x130 kernel/rcu/update.c:104 rcu_read_lock_held+0x5a/0xb0 kernel/rcu/update.c:305 hlist_bl_first_rcu include/linux/rculist_bl.h:24 [inline] __d_lookup_rcu+0x53a/0x6c0 fs/dcache.c:2244 lookup_fast+0xe0/0x6d0 fs/namei.c:1453 walk_component+0xc6/0x6a0 fs/namei.c:1842 lookup_last fs/namei.c:2295 [inline] path_lookupat.isra.0+0x180/0x530 fs/namei.c:2319 filename_lookup+0x1a3/0x3e0 fs/namei.c:2352 user_path_at include/linux/namei.h:59 [inline] vfs_statx+0x119/0x1e0 fs/stat.c:197 vfs_lstat include/linux/fs.h:3284 [inline] __do_sys_newlstat+0x96/0x120 fs/stat.c:364 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: 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 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 the dependencies between the lock to be acquired and SOFTIRQ-irq-unsafe lock: -> (shmlock_user_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] user_shm_lock+0xab/0x230 mm/mlock.c:855 hugetlb_file_setup+0x4e1/0x677 fs/hugetlbfs/inode.c:1416 newseg+0x460/0xe60 ipc/shm.c:652 ipcget_new ipc/util.c:344 [inline] ipcget+0xf0/0xcb0 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+0x139/0x1a0 ipc/shm.c:745 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] user_shm_lock+0xab/0x230 mm/mlock.c:855 hugetlb_file_setup+0x4e1/0x677 fs/hugetlbfs/inode.c:1416 newseg+0x460/0xe60 ipc/shm.c:652 ipcget_new ipc/util.c:344 [inline] ipcget+0xf0/0xcb0 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+0x139/0x1a0 ipc/shm.c:745 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 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+0xab/0x230 mm/mlock.c:855 shmem_lock+0x1dd/0x2d0 mm/shmem.c:2184 shmctl_do_lock+0x73f/0x8f0 ipc/shm.c:1111 ksys_shmctl.constprop.0+0x203/0x350 ipc/shm.c:1188 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 } ... key at: [] shmlock_user_lock+0x18/0x5c0 ... acquired at: __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+0xab/0x230 mm/mlock.c:855 shmem_lock+0x1dd/0x2d0 mm/shmem.c:2184 shmctl_do_lock+0x73f/0x8f0 ipc/shm.c:1111 ksys_shmctl.constprop.0+0x203/0x350 ipc/shm.c:1188 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 -> (&info->lock){....}-{2:2} { 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 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 stack backtrace: CPU: 1 PID: 7433 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_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 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 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:00007feebbe5dc78 EFLAGS: 00000246 ORIG_RAX: 000000000000004d RAX: ffffffffffffffda RBX: 00000000004dc580 RCX: 000000000045c829 RDX: 0000000000000000 RSI: 00000000000001ff RDI: 0000000000000005 RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000000e9 R14: 00000000004c3701 R15: 00007feebbe5e6d4