====================================================== WARNING: possible circular locking dependency detected 6.15.0-rc4-syzkaller-00011-gf15d97df5afa #0 Not tainted ------------------------------------------------------ syz.6.113/7092 is trying to acquire lock: ffff888026c06610 (sb_internal#6){.+.+}-{0:0}, at: nilfs_page_mkwrite+0x8b0/0xc20 fs/nilfs2/file.c:95 but task is already holding lock: ffff888026c06518 (sb_pagefaults#5){.+.+}-{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#5){.+.+}-{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 do_user_addr_fault+0x764/0x1390 arch/x86/mm/fault.c:1388 handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x68/0x110 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 -> #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_at_level+0x34e/0x3d0 fs/nilfs2/bmap.c:88 nilfs_bmap_lookup fs/nilfs2/bmap.h:182 [inline] nilfs_mdt_submit_block+0x3a3/0x830 fs/nilfs2/mdt.c:144 nilfs_mdt_read_block+0xad/0x320 fs/nilfs2/mdt.c:188 nilfs_mdt_get_block+0x11f/0xab0 fs/nilfs2/mdt.c:254 nilfs_palloc_get_block+0x18d/0x2b0 fs/nilfs2/alloc.c:239 nilfs_palloc_get_entry_block+0x8c/0xa0 fs/nilfs2/alloc.c:355 nilfs_ifile_get_inode_block+0xf0/0x190 fs/nilfs2/ifile.c:137 __nilfs_read_inode fs/nilfs2/inode.c:453 [inline] nilfs_iget+0x201/0x810 fs/nilfs2/inode.c:564 nilfs_get_root_dentry+0x28/0x230 fs/nilfs2/super.c:915 nilfs_fill_super+0x47f/0x650 fs/nilfs2/super.c:1098 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 -> #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 block_write_begin+0x8a/0x120 fs/buffer.c:2262 nilfs_write_begin+0xa3/0x120 fs/nilfs2/inode.c:232 generic_perform_write+0x2c4/0x910 mm/filemap.c:4103 __generic_file_write_iter+0x1ae/0x230 mm/filemap.c:4217 generic_file_write_iter+0x10f/0x540 mm/filemap.c:4246 do_iter_readv_writev+0x56b/0x7f0 fs/read_write.c:-1 vfs_writev+0x306/0x9a0 fs/read_write.c:1055 do_pwritev fs/read_write.c:1151 [inline] __do_sys_pwritev2 fs/read_write.c:1209 [inline] __se_sys_pwritev2+0x179/0x290 fs/read_write.c:1200 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_dirty_inode+0x157/0x200 fs/nilfs2/inode.c:1088 __mark_inode_dirty+0x2ce/0xdf0 fs/fs-writeback.c:2527 generic_update_time fs/inode.c:2064 [inline] inode_update_time fs/inode.c:2077 [inline] __file_update_time fs/inode.c:2305 [inline] file_update_time+0x40c/0x490 fs/inode.c:2335 __generic_file_write_iter+0x97/0x230 mm/filemap.c:4201 generic_file_write_iter+0x10f/0x540 mm/filemap.c:4246 do_iter_readv_writev+0x56b/0x7f0 fs/read_write.c:-1 vfs_writev+0x306/0x9a0 fs/read_write.c:1055 do_pwritev fs/read_write.c:1151 [inline] __do_sys_pwritev2 fs/read_write.c:1209 [inline] __se_sys_pwritev2+0x179/0x290 fs/read_write.c:1200 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 do_user_addr_fault+0x764/0x1390 arch/x86/mm/fault.c:1388 handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x68/0x110 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#6 --> &mm->mmap_lock --> sb_pagefaults#5 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(sb_pagefaults#5); lock(&mm->mmap_lock); lock(sb_pagefaults#5); rlock(sb_internal#6); *** DEADLOCK *** 2 locks held by syz.6.113/7092: #0: ffff88807e295be0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:203 [inline] #0: ffff88807e295be0 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/memory.c:6346 [inline] #0: ffff88807e295be0 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x32/0x300 mm/memory.c:6406 #1: ffff888026c06518 (sb_pagefaults#5){.+.+}-{0:0}, at: do_page_mkwrite+0x14a/0x310 mm/memory.c:3287 stack backtrace: CPU: 0 UID: 0 PID: 7092 Comm: syz.6.113 Not tainted 6.15.0-rc4-syzkaller-00011-gf15d97df5afa #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 do_user_addr_fault+0x764/0x1390 arch/x86/mm/fault.c:1388 handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x68/0x110 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7fc5e035665d Code: 00 66 66 2e 0f 1f 84 00 00 00 00 00 90 48 89 f8 48 83 fa 20 72 37 c5 fe 6f 06 48 83 fa 40 0f 87 b9 00 00 00 c5 fe 6f 4c 16 e0 fe 7f 07 c5 fe 7f 4c 17 e0 0f 01 d6 75 04 c5 f8 77 c3 c5 fc 77 RSP: 002b:00007ffeaf0ce8a8 EFLAGS: 00010283 RAX: 0000200000000380 RBX: 0000000000000004 RCX: ffffffffffffffdf RDX: 0000000000000020 RSI: 00007fc5dfe01592 RDI: 0000200000000380 RBP: 00007fc5e05b7ba0 R08: 00007fc5e0200000 R09: 0000000000000040 R10: 0000000000000000 R11: 0000000000000000 R12: 00007fc5e05b5fac R13: 00007fc5e05b5fa0 R14: fffffffffffffffe R15: 00007ffeaf0ce9c0