====================================================== WARNING: possible circular locking dependency detected 6.15.0-rc4-syzkaller-00021-gca91b9500108 #0 Not tainted ------------------------------------------------------ syz.1.991/10122 is trying to acquire lock: ffff888057558610 (sb_internal#2){.+.+}-{0:0}, at: nilfs_page_mkwrite+0x963/0xcd0 fs/nilfs2/file.c:95 but task is already holding lock: ffff888057558518 (sb_pagefaults#7){.+.+}-{0:0}, at: do_page_mkwrite+0x174/0x380 mm/memory.c:3287 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (sb_pagefaults#7){.+.+}-{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+0x248/0xcd0 fs/nilfs2/file.c:57 do_page_mkwrite+0x174/0x380 mm/memory.c:3287 do_shared_fault mm/memory.c:5594 [inline] do_fault mm/memory.c:5656 [inline] do_pte_missing+0x29c/0x3fb0 mm/memory.c:4160 handle_pte_fault mm/memory.c:5997 [inline] __handle_mm_fault+0x103d/0x2a40 mm/memory.c:6140 handle_mm_fault+0x3fe/0xad0 mm/memory.c:6309 do_user_addr_fault+0x7a6/0x1370 arch/x86/mm/fault.c:1388 handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 -> #4 (&mm->mmap_lock){++++}-{4:4}: __might_fault mm/memory.c:7151 [inline] __might_fault+0x113/0x190 mm/memory.c:7145 _copy_to_iter+0x1c6/0x15a0 lib/iov_iter.c:184 copy_page_to_iter lib/iov_iter.c:362 [inline] copy_page_to_iter+0xf1/0x180 lib/iov_iter.c:349 copy_folio_to_iter include/linux/uio.h:198 [inline] filemap_read+0x6b1/0xe90 mm/filemap.c:2753 blkdev_read_iter+0x1ac/0x500 block/fops.c:809 new_sync_read fs/read_write.c:489 [inline] vfs_read+0x8cb/0xc70 fs/read_write.c:570 ksys_read+0x12a/0x240 fs/read_write.c:713 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #3 (&sb->s_type->i_mutex_key#8){++++}-{4:4}: down_write+0x92/0x200 kernel/locking/rwsem.c:1577 inode_lock include/linux/fs.h:867 [inline] set_blocksize+0x1e0/0x500 block/bdev.c:203 sb_set_blocksize block/bdev.c:224 [inline] sb_min_blocksize+0x149/0x270 block/bdev.c:239 init_nilfs+0x94/0x15a0 fs/nilfs2/the_nilfs.c:710 nilfs_fill_super fs/nilfs2/super.c:1060 [inline] nilfs_get_tree+0x654/0x10f0 fs/nilfs2/super.c:1228 vfs_get_tree+0x8e/0x340 fs/super.c:1759 do_new_mount fs/namespace.c:3884 [inline] path_mount+0x14d4/0x1f20 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] __x64_sys_mount+0x28d/0x310 fs/namespace.c:4412 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&nilfs->ns_sem){++++}-{4:4}: down_write+0x92/0x200 kernel/locking/rwsem.c:1577 nilfs_set_error fs/nilfs2/super.c:92 [inline] __nilfs_error+0x232/0x4d0 fs/nilfs2/super.c:141 nilfs_bmap_convert_error fs/nilfs2/bmap.c:35 [inline] nilfs_bmap_truncate+0x2c4/0x320 fs/nilfs2/bmap.c:294 nilfs_truncate_bmap+0x14a/0x350 fs/nilfs2/inode.c:776 nilfs_evict_inode+0x214/0x550 fs/nilfs2/inode.c:881 evict+0x3e6/0x920 fs/inode.c:810 iput_final fs/inode.c:1898 [inline] iput fs/inode.c:1924 [inline] iput+0x521/0x880 fs/inode.c:1910 do_unlinkat+0x518/0x6a0 fs/namei.c:4650 __do_sys_unlink fs/namei.c:4689 [inline] __se_sys_unlink fs/namei.c:4687 [inline] __x64_sys_unlink+0xc5/0x110 fs/namei.c:4687 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&nilfs->ns_segctor_sem){++++}-{4:4}: down_read+0x9b/0x480 kernel/locking/rwsem.c:1524 nilfs_transaction_begin+0x326/0xa40 fs/nilfs2/segment.c:221 nilfs_unlink+0xb0/0x1e0 fs/nilfs2/namei.c:316 vfs_unlink+0x2fe/0x9b0 fs/namei.c:4579 do_unlinkat+0x4c5/0x6a0 fs/namei.c:4643 __do_sys_unlink fs/namei.c:4689 [inline] __se_sys_unlink fs/namei.c:4687 [inline] __x64_sys_unlink+0xc5/0x110 fs/namei.c:4687 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #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+0x1173/0x1ba0 kernel/locking/lockdep.c:5235 lock_acquire kernel/locking/lockdep.c:5866 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5823 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+0x21b/0xa40 fs/nilfs2/segment.c:218 nilfs_page_mkwrite+0x963/0xcd0 fs/nilfs2/file.c:95 do_page_mkwrite+0x174/0x380 mm/memory.c:3287 do_shared_fault mm/memory.c:5594 [inline] do_fault mm/memory.c:5656 [inline] do_pte_missing+0x29c/0x3fb0 mm/memory.c:4160 handle_pte_fault mm/memory.c:5997 [inline] __handle_mm_fault+0x103d/0x2a40 mm/memory.c:6140 handle_mm_fault+0x3fe/0xad0 mm/memory.c:6309 do_user_addr_fault+0x7a6/0x1370 arch/x86/mm/fault.c:1388 handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 other info that might help us debug this: Chain exists of: sb_internal#2 --> &mm->mmap_lock --> sb_pagefaults#7 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(sb_pagefaults#7); lock(&mm->mmap_lock); lock(sb_pagefaults#7); rlock(sb_internal#2); *** DEADLOCK *** 2 locks held by syz.1.991/10122: #0: ffff8880491c65e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:203 [inline] #0: ffff8880491c65e0 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/memory.c:6346 [inline] #0: ffff8880491c65e0 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x35/0x6e0 mm/memory.c:6406 #1: ffff888057558518 (sb_pagefaults#7){.+.+}-{0:0}, at: do_page_mkwrite+0x174/0x380 mm/memory.c:3287 stack backtrace: CPU: 1 UID: 0 PID: 10122 Comm: syz.1.991 Not tainted 6.15.0-rc4-syzkaller-00021-gca91b9500108 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x275/0x350 kernel/locking/lockdep.c:2079 check_noncircular+0x14c/0x170 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+0x1173/0x1ba0 kernel/locking/lockdep.c:5235 lock_acquire kernel/locking/lockdep.c:5866 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5823 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+0x21b/0xa40 fs/nilfs2/segment.c:218 nilfs_page_mkwrite+0x963/0xcd0 fs/nilfs2/file.c:95 do_page_mkwrite+0x174/0x380 mm/memory.c:3287 do_shared_fault mm/memory.c:5594 [inline] do_fault mm/memory.c:5656 [inline] do_pte_missing+0x29c/0x3fb0 mm/memory.c:4160 handle_pte_fault mm/memory.c:5997 [inline] __handle_mm_fault+0x103d/0x2a40 mm/memory.c:6140 handle_mm_fault+0x3fe/0xad0 mm/memory.c:6309 do_user_addr_fault+0x7a6/0x1370 arch/x86/mm/fault.c:1388 handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7f5f6ef55f1b Code: fa 10 73 2d 83 fa 08 73 46 83 fa 04 73 16 83 fa 01 7c 10 8a 0e 74 0a 0f b7 74 16 fe 66 89 74 17 fe 88 0f c3 8b 4c 16 fc 8b 36 <89> 4c 17 fc 89 37 c3 c5 fa 6f 06 c5 fa 6f 4c 16 f0 c5 fa 7f 07 c5 RSP: 002b:00007ffcb3a14c18 EFLAGS: 00010202 RAX: 0000200000003a40 RBX: 0000000000000004 RCX: 0000000000736f64 RDX: 0000000000000006 RSI: 000000006f64736d RDI: 0000200000003a40 RBP: 00007f5f6f1b7ba0 R08: 00007f5f6ee00000 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000009 R12: 00007f5f6f1b5fac R13: 00007f5f6f1b5fa0 R14: fffffffffffffffe R15: 00007ffcb3a14d30