====================================================== WARNING: possible circular locking dependency detected 6.15.0-rc4-syzkaller-00021-gca91b9500108 #0 Not tainted ------------------------------------------------------ syz.7.638/11630 is trying to acquire lock: ffff88806a4ac610 (sb_internal#6){.+.+}-{0:0}, at: nilfs_page_mkwrite+0x8b0/0xc20 fs/nilfs2/file.c:95 but task is already holding lock: ffff88806a4ac518 (sb_pagefaults#7){.+.+}-{0:0}, at: do_page_mkwrite+0x14a/0x310 mm/memory.c:3287 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #6 (sb_pagefaults#7){.+.+}-{0:0}: lock_acquire+0x120/0x360 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_pagefault include/linux/fs.h:1948 [inline] nilfs_page_mkwrite+0x21e/0xc20 fs/nilfs2/file.c:57 do_page_mkwrite+0x14a/0x310 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+0x18d2/0x5380 mm/memory.c:6140 handle_mm_fault+0x2d5/0x7f0 mm/memory.c:6309 faultin_page mm/gup.c:1193 [inline] __get_user_pages+0x16f0/0x2a40 mm/gup.c:1491 __get_user_pages_locked mm/gup.c:1821 [inline] __gup_longterm_locked+0x105d/0x15b0 mm/gup.c:2523 gup_fast_fallback+0x1843/0x1d60 mm/gup.c:3417 iov_iter_extract_user_pages lib/iov_iter.c:1849 [inline] iov_iter_extract_pages+0x35a/0x5e0 lib/iov_iter.c:1912 dio_refill_pages fs/direct-io.c:172 [inline] dio_get_page fs/direct-io.c:213 [inline] do_direct_IO fs/direct-io.c:915 [inline] __blockdev_direct_IO+0x10ed/0x3310 fs/direct-io.c:1243 blockdev_direct_IO include/linux/fs.h:3422 [inline] nilfs_direct_IO+0xed/0x120 fs/nilfs2/inode.c:267 generic_file_read_iter+0x319/0x510 mm/filemap.c:2871 new_sync_read fs/read_write.c:489 [inline] vfs_read+0x4cd/0x980 fs/read_write.c:570 ksys_read+0x145/0x250 fs/read_write.c:713 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #5 (&mm->mmap_lock){++++}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866 __might_fault+0xcc/0x130 mm/memory.c:7151 _copy_to_iter+0xf3/0x15a0 lib/iov_iter.c:184 copy_page_to_iter+0xa7/0x150 lib/iov_iter.c:362 copy_folio_to_iter include/linux/uio.h:198 [inline] filemap_read+0x78d/0x11d0 mm/filemap.c:2753 blkdev_read_iter+0x30a/0x440 block/fops.c:809 new_sync_read fs/read_write.c:489 [inline] vfs_read+0x4cd/0x980 fs/read_write.c:570 ksys_read+0x145/0x250 fs/read_write.c:713 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #4 (&sb->s_type->i_mutex_key#7){++++}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866 down_write+0x96/0x1f0 kernel/locking/rwsem.c:1577 inode_lock include/linux/fs.h:867 [inline] set_blocksize+0x23b/0x500 block/bdev.c:203 sb_set_blocksize block/bdev.c:224 [inline] sb_min_blocksize+0x119/0x210 block/bdev.c:239 init_nilfs+0x43/0x690 fs/nilfs2/the_nilfs.c:710 nilfs_fill_super+0x8f/0x650 fs/nilfs2/super.c:1060 nilfs_get_tree+0x4f4/0x870 fs/nilfs2/super.c:1228 vfs_get_tree+0x8f/0x2b0 fs/super.c:1759 do_new_mount+0x24a/0xa40 fs/namespace.c:3884 do_mount fs/namespace.c:4224 [inline] __do_sys_mount fs/namespace.c:4435 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4412 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #3 (&nilfs->ns_sem){++++}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866 down_write+0x96/0x1f0 kernel/locking/rwsem.c:1577 nilfs_set_error fs/nilfs2/super.c:92 [inline] __nilfs_error+0x1ca/0x4b0 fs/nilfs2/super.c:141 nilfs_bmap_convert_error fs/nilfs2/bmap.c:35 [inline] nilfs_bmap_lookup_contig+0x13e/0x160 fs/nilfs2/bmap.c:100 nilfs_get_block+0x1fb/0x8f0 fs/nilfs2/inode.c:84 __block_write_begin_int+0x6b2/0x1900 fs/buffer.c:2151 nilfs_prepare_chunk fs/nilfs2/dir.c:86 [inline] nilfs_add_link+0x855/0xd50 fs/nilfs2/dir.c:492 nilfs_add_nondir fs/nilfs2/namei.c:37 [inline] nilfs_symlink+0x28a/0x3a0 fs/nilfs2/namei.c:176 vfs_symlink+0x140/0x2f0 fs/namei.c:4723 do_symlinkat+0x1b1/0x3f0 fs/namei.c:4749 __do_sys_symlink fs/namei.c:4770 [inline] __se_sys_symlink fs/namei.c:4768 [inline] __x64_sys_symlink+0x7a/0x90 fs/namei.c:4768 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&dat_lock_key){.+.+}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866 down_read+0x46/0x2e0 kernel/locking/rwsem.c:1524 nilfs_get_block+0x1b1/0x8f0 fs/nilfs2/inode.c:83 __block_write_begin_int+0x6b2/0x1900 fs/buffer.c:2151 nilfs_prepare_chunk fs/nilfs2/dir.c:86 [inline] nilfs_delete_entry+0x376/0x520 fs/nilfs2/dir.c:549 nilfs_do_unlink+0x1c2/0x3a0 fs/nilfs2/namei.c:299 nilfs_unlink+0xee/0x1e0 fs/nilfs2/namei.c:320 vfs_unlink+0x391/0x650 fs/namei.c:4579 do_unlinkat+0x350/0x560 fs/namei.c:4643 __do_sys_unlink fs/namei.c:4689 [inline] __se_sys_unlink fs/namei.c:4687 [inline] __x64_sys_unlink+0x47/0x50 fs/namei.c:4687 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&nilfs->ns_segctor_sem){++++}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866 down_read+0x46/0x2e0 kernel/locking/rwsem.c:1524 nilfs_transaction_begin+0x365/0x710 fs/nilfs2/segment.c:221 nilfs_unlink+0xbc/0x1e0 fs/nilfs2/namei.c:316 vfs_unlink+0x391/0x650 fs/namei.c:4579 do_unlinkat+0x350/0x560 fs/namei.c:4643 __do_sys_unlink fs/namei.c:4689 [inline] __se_sys_unlink fs/namei.c:4687 [inline] __x64_sys_unlink+0x47/0x50 fs/namei.c:4687 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (sb_internal#6){.+.+}-{0:0}: check_prev_add kernel/locking/lockdep.c:3166 [inline] check_prevs_add kernel/locking/lockdep.c:3285 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3909 __lock_acquire+0xaac/0xd20 kernel/locking/lockdep.c:5235 lock_acquire+0x120/0x360 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+0x268/0x710 fs/nilfs2/segment.c:218 nilfs_page_mkwrite+0x8b0/0xc20 fs/nilfs2/file.c:95 do_page_mkwrite+0x14a/0x310 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+0x18d2/0x5380 mm/memory.c:6140 handle_mm_fault+0x2d5/0x7f0 mm/memory.c:6309 faultin_page mm/gup.c:1193 [inline] __get_user_pages+0x16f0/0x2a40 mm/gup.c:1491 __get_user_pages_locked mm/gup.c:1821 [inline] __gup_longterm_locked+0x105d/0x15b0 mm/gup.c:2523 gup_fast_fallback+0x1843/0x1d60 mm/gup.c:3417 iov_iter_extract_user_pages lib/iov_iter.c:1849 [inline] iov_iter_extract_pages+0x35a/0x5e0 lib/iov_iter.c:1912 dio_refill_pages fs/direct-io.c:172 [inline] dio_get_page fs/direct-io.c:213 [inline] do_direct_IO fs/direct-io.c:915 [inline] __blockdev_direct_IO+0x10ed/0x3310 fs/direct-io.c:1243 blockdev_direct_IO include/linux/fs.h:3422 [inline] nilfs_direct_IO+0xed/0x120 fs/nilfs2/inode.c:267 generic_file_read_iter+0x319/0x510 mm/filemap.c:2871 new_sync_read fs/read_write.c:489 [inline] vfs_read+0x4cd/0x980 fs/read_write.c:570 ksys_read+0x145/0x250 fs/read_write.c:713 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: sb_internal#6 --> &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#6); *** DEADLOCK *** 4 locks held by syz.7.638/11630: #0: ffff888034761b38 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1213 #1: ffff8880794c8f60 (&sb->s_type->i_mutex_key#43){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #1: ffff8880794c8f60 (&sb->s_type->i_mutex_key#43){+.+.}-{4:4}, at: __blockdev_direct_IO+0x318/0x3310 fs/direct-io.c:1140 #2: ffff88802f6e0be0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock_killable include/linux/mmap_lock.h:193 [inline] #2: ffff88802f6e0be0 (&mm->mmap_lock){++++}-{4:4}, at: __get_user_pages_locked mm/gup.c:1812 [inline] #2: ffff88802f6e0be0 (&mm->mmap_lock){++++}-{4:4}, at: __gup_longterm_locked+0x1005/0x15b0 mm/gup.c:2523 #3: ffff88806a4ac518 (sb_pagefaults#7){.+.+}-{0:0}, at: do_page_mkwrite+0x14a/0x310 mm/memory.c:3287 stack backtrace: CPU: 0 UID: 0 PID: 11630 Comm: syz.7.638 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_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2079 check_noncircular+0x134/0x160 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+0xb9b/0x2140 kernel/locking/lockdep.c:3909 __lock_acquire+0xaac/0xd20 kernel/locking/lockdep.c:5235 lock_acquire+0x120/0x360 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+0x268/0x710 fs/nilfs2/segment.c:218 nilfs_page_mkwrite+0x8b0/0xc20 fs/nilfs2/file.c:95 do_page_mkwrite+0x14a/0x310 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+0x18d2/0x5380 mm/memory.c:6140 handle_mm_fault+0x2d5/0x7f0 mm/memory.c:6309 faultin_page mm/gup.c:1193 [inline] __get_user_pages+0x16f0/0x2a40 mm/gup.c:1491 __get_user_pages_locked mm/gup.c:1821 [inline] __gup_longterm_locked+0x105d/0x15b0 mm/gup.c:2523 gup_fast_fallback+0x1843/0x1d60 mm/gup.c:3417 iov_iter_extract_user_pages lib/iov_iter.c:1849 [inline] iov_iter_extract_pages+0x35a/0x5e0 lib/iov_iter.c:1912 dio_refill_pages fs/direct-io.c:172 [inline] dio_get_page fs/direct-io.c:213 [inline] do_direct_IO fs/direct-io.c:915 [inline] __blockdev_direct_IO+0x10ed/0x3310 fs/direct-io.c:1243 blockdev_direct_IO include/linux/fs.h:3422 [inline] nilfs_direct_IO+0xed/0x120 fs/nilfs2/inode.c:267 generic_file_read_iter+0x319/0x510 mm/filemap.c:2871 new_sync_read fs/read_write.c:489 [inline] vfs_read+0x4cd/0x980 fs/read_write.c:570 ksys_read+0x145/0x250 fs/read_write.c:713 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7f2638e969 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f7f241f6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f7f265b5fa0 RCX: 00007f7f2638e969 RDX: 0000000000001000 RSI: 0000200000000400 RDI: 0000000000000006 RBP: 00007f7f26410ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f7f265b5fa0 R15: 00007fff0ff5d298