====================================================== WARNING: possible circular locking dependency detected 6.15.0-rc4-syzkaller-ge0f4c8dd9d2d #0 Not tainted ------------------------------------------------------ syz.4.142/7301 is trying to acquire lock: ffff0000db94a610 (sb_internal#2){.+.+}-{0:0}, at: nilfs_page_mkwrite+0x8d0/0xca8 fs/nilfs2/file.c:95 but task is already holding lock: ffff0000db94a518 (sb_pagefaults#3){.+.+}-{0:0}, at: do_page_mkwrite+0x138/0x2b8 mm/memory.c:3287 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #6 (sb_pagefaults#3){.+.+}-{0:0}: percpu_down_read include/linux/percpu-rwsem.h:52 [inline] __sb_start_write include/linux/fs.h:1783 [inline] sb_start_pagefault include/linux/fs.h:1948 [inline] nilfs_page_mkwrite+0x1ec/0xca8 fs/nilfs2/file.c:57 do_page_mkwrite+0x138/0x2b8 mm/memory.c:3287 do_shared_fault mm/memory.c:5594 [inline] do_fault mm/memory.c:5656 [inline] do_pte_missing mm/memory.c:4160 [inline] handle_pte_fault mm/memory.c:5997 [inline] __handle_mm_fault mm/memory.c:6140 [inline] handle_mm_fault+0x1998/0x4cec mm/memory.c:6309 do_page_fault+0x598/0x1554 arch/arm64/mm/fault.c:690 do_translation_fault+0xc4/0x114 arch/arm64/mm/fault.c:783 do_mem_abort+0x70/0x194 arch/arm64/mm/fault.c:919 el0_da+0x64/0x160 arch/arm64/kernel/entry-common.c:604 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:765 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 -> #5 (&mm->mmap_lock){++++}-{4:4}: __might_fault+0xc4/0x124 mm/memory.c:7151 _copy_to_iter+0xe0/0x1394 lib/iov_iter.c:184 copy_page_to_iter+0x24c/0x348 lib/iov_iter.c:362 copy_folio_to_iter include/linux/uio.h:198 [inline] filemap_read+0x668/0xf4c mm/filemap.c:2753 blkdev_read_iter+0x2b0/0x3dc block/fops.c:809 new_sync_read fs/read_write.c:489 [inline] vfs_read+0x5fc/0x898 fs/read_write.c:570 ksys_read+0x120/0x210 fs/read_write.c:713 __do_sys_read fs/read_write.c:722 [inline] __se_sys_read fs/read_write.c:720 [inline] __arm64_sys_read+0x7c/0x90 fs/read_write.c:720 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 -> #4 (&sb->s_type->i_mutex_key#8){++++}-{4:4}: down_write+0x50/0xc0 kernel/locking/rwsem.c:1577 inode_lock include/linux/fs.h:867 [inline] set_blocksize+0x1c4/0x440 block/bdev.c:203 sb_set_blocksize block/bdev.c:224 [inline] sb_min_blocksize+0x118/0x1fc block/bdev.c:239 init_nilfs+0x4c/0x584 fs/nilfs2/the_nilfs.c:710 nilfs_fill_super+0x94/0x568 fs/nilfs2/super.c:1060 nilfs_get_tree+0x378/0x664 fs/nilfs2/super.c:1228 vfs_get_tree+0x90/0x28c fs/super.c:1759 do_new_mount+0x228/0x814 fs/namespace.c:3884 path_mount+0x5b4/0xde0 fs/namespace.c:4211 do_mount fs/namespace.c:4224 [inline] __do_sys_mount fs/namespace.c:4435 [inline] __se_sys_mount fs/namespace.c:4412 [inline] __arm64_sys_mount+0x3e8/0x468 fs/namespace.c:4412 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 -> #3 (&nilfs->ns_sem){++++}-{4:4}: down_write+0x50/0xc0 kernel/locking/rwsem.c:1577 nilfs_set_error fs/nilfs2/super.c:92 [inline] __nilfs_error+0x164/0x3bc fs/nilfs2/super.c:141 nilfs_bmap_convert_error fs/nilfs2/bmap.c:35 [inline] nilfs_bmap_lookup_contig+0x114/0x13c fs/nilfs2/bmap.c:100 nilfs_get_block+0x1a0/0x7a8 fs/nilfs2/inode.c:84 block_truncate_page+0x2f4/0x6b8 fs/buffer.c:2702 nilfs_truncate+0x1ec/0x400 fs/nilfs2/inode.c:804 nilfs_setattr+0x1c8/0x26c fs/nilfs2/inode.c:920 notify_change+0x9a4/0xc50 fs/attr.c:552 do_truncate+0x178/0x1f0 fs/open.c:65 vfs_truncate+0x398/0x444 fs/open.c:115 do_sys_truncate+0xe4/0x1a8 fs/open.c:138 __do_sys_truncate fs/open.c:150 [inline] __se_sys_truncate fs/open.c:148 [inline] __arm64_sys_truncate+0x5c/0x74 fs/open.c:148 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 -> #2 (&dat_lock_key){.+.+}-{4:4}: down_read+0x58/0x2f8 kernel/locking/rwsem.c:1524 nilfs_get_block+0x170/0x7a8 fs/nilfs2/inode.c:83 block_truncate_page+0x2f4/0x6b8 fs/buffer.c:2702 nilfs_truncate+0x1ec/0x400 fs/nilfs2/inode.c:804 nilfs_setattr+0x1c8/0x26c fs/nilfs2/inode.c:920 notify_change+0x9a4/0xc50 fs/attr.c:552 do_truncate+0x178/0x1f0 fs/open.c:65 vfs_truncate+0x398/0x444 fs/open.c:115 do_sys_truncate+0xe4/0x1a8 fs/open.c:138 __do_sys_truncate fs/open.c:150 [inline] __se_sys_truncate fs/open.c:148 [inline] __arm64_sys_truncate+0x5c/0x74 fs/open.c:148 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 -> #1 (&nilfs->ns_segctor_sem){++++}-{4:4}: down_read+0x58/0x2f8 kernel/locking/rwsem.c:1524 nilfs_transaction_begin+0x35c/0x6f8 fs/nilfs2/segment.c:221 nilfs_setattr+0x110/0x26c fs/nilfs2/inode.c:912 notify_change+0x9a4/0xc50 fs/attr.c:552 do_truncate+0x178/0x1f0 fs/open.c:65 vfs_truncate+0x398/0x444 fs/open.c:115 do_sys_truncate+0xe4/0x1a8 fs/open.c:138 __do_sys_truncate fs/open.c:150 [inline] __se_sys_truncate fs/open.c:148 [inline] __arm64_sys_truncate+0x5c/0x74 fs/open.c:148 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 -> #0 (sb_internal#2){.+.+}-{0:0}: check_prev_add kernel/locking/lockdep.c:3166 [inline] check_prevs_add kernel/locking/lockdep.c:3285 [inline] validate_chain kernel/locking/lockdep.c:3909 [inline] __lock_acquire+0x1728/0x3058 kernel/locking/lockdep.c:5235 lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5866 percpu_down_read include/linux/percpu-rwsem.h:52 [inline] __sb_start_write include/linux/fs.h:1783 [inline] sb_start_intwrite include/linux/fs.h:1966 [inline] nilfs_transaction_begin+0x1f4/0x6f8 fs/nilfs2/segment.c:218 nilfs_page_mkwrite+0x8d0/0xca8 fs/nilfs2/file.c:95 do_page_mkwrite+0x138/0x2b8 mm/memory.c:3287 do_shared_fault mm/memory.c:5594 [inline] do_fault mm/memory.c:5656 [inline] do_pte_missing mm/memory.c:4160 [inline] handle_pte_fault mm/memory.c:5997 [inline] __handle_mm_fault mm/memory.c:6140 [inline] handle_mm_fault+0x1998/0x4cec mm/memory.c:6309 do_page_fault+0x598/0x1554 arch/arm64/mm/fault.c:690 do_translation_fault+0xc4/0x114 arch/arm64/mm/fault.c:783 do_mem_abort+0x70/0x194 arch/arm64/mm/fault.c:919 el0_da+0x64/0x160 arch/arm64/kernel/entry-common.c:604 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:765 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 other info that might help us debug this: Chain exists of: sb_internal#2 --> &mm->mmap_lock --> sb_pagefaults#3 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(sb_pagefaults#3); lock(&mm->mmap_lock); lock(sb_pagefaults#3); rlock(sb_internal#2); *** DEADLOCK *** 2 locks held by syz.4.142/7301: #0: ffff0000cca734d0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:203 [inline] #0: ffff0000cca734d0 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/memory.c:6346 [inline] #0: ffff0000cca734d0 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x38/0x2d8 mm/memory.c:6406 #1: ffff0000db94a518 (sb_pagefaults#3){.+.+}-{0:0}, at: do_page_mkwrite+0x138/0x2b8 mm/memory.c:3287 stack backtrace: CPU: 0 UID: 0 PID: 7301 Comm: syz.4.142 Not tainted 6.15.0-rc4-syzkaller-ge0f4c8dd9d2d #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:466 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 dump_stack+0x1c/0x28 lib/dump_stack.c:129 print_circular_bug+0x324/0x32c kernel/locking/lockdep.c:2079 check_noncircular+0x154/0x174 kernel/locking/lockdep.c:2211 check_prev_add kernel/locking/lockdep.c:3166 [inline] check_prevs_add kernel/locking/lockdep.c:3285 [inline] validate_chain kernel/locking/lockdep.c:3909 [inline] __lock_acquire+0x1728/0x3058 kernel/locking/lockdep.c:5235 lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5866 percpu_down_read include/linux/percpu-rwsem.h:52 [inline] __sb_start_write include/linux/fs.h:1783 [inline] sb_start_intwrite include/linux/fs.h:1966 [inline] nilfs_transaction_begin+0x1f4/0x6f8 fs/nilfs2/segment.c:218 nilfs_page_mkwrite+0x8d0/0xca8 fs/nilfs2/file.c:95 do_page_mkwrite+0x138/0x2b8 mm/memory.c:3287 do_shared_fault mm/memory.c:5594 [inline] do_fault mm/memory.c:5656 [inline] do_pte_missing mm/memory.c:4160 [inline] handle_pte_fault mm/memory.c:5997 [inline] __handle_mm_fault mm/memory.c:6140 [inline] handle_mm_fault+0x1998/0x4cec mm/memory.c:6309 do_page_fault+0x598/0x1554 arch/arm64/mm/fault.c:690 do_translation_fault+0xc4/0x114 arch/arm64/mm/fault.c:783 do_mem_abort+0x70/0x194 arch/arm64/mm/fault.c:919 el0_da+0x64/0x160 arch/arm64/kernel/entry-common.c:604 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:765 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600