====================================================== WARNING: possible circular locking dependency detected 6.15.0-rc5-syzkaller-00136-g9c69f8884904 #0 Not tainted ------------------------------------------------------ syz.2.311/8899 is trying to acquire lock: ffff88802ffde610 (sb_internal#7){.+.+}-{0:0}, at: nilfs_page_mkwrite+0x8b0/0xc20 fs/nilfs2/file.c:95 but task is already holding lock: ffff88802ffde518 (sb_pagefaults#4){.+.+}-{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: -> #5 (sb_pagefaults#4){.+.+}-{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 rep_movs_alternative+0x4a/0x90 arch/x86/lib/copy_user_64.S:68 copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline] copy_to_user_iter lib/iov_iter.c:25 [inline] iterate_iovec include/linux/iov_iter.h:52 [inline] iterate_and_advance2 include/linux/iov_iter.h:302 [inline] iterate_and_advance include/linux/iov_iter.h:328 [inline] _copy_to_iter+0x484/0x15a0 lib/iov_iter.c:185 copy_to_iter include/linux/uio.h:220 [inline] seq_read_iter+0xbeb/0xe10 fs/seq_file.c:281 seq_read+0x2e2/0x3d0 fs/seq_file.c:162 pde_read fs/proc/inode.c:308 [inline] proc_reg_read+0x1e6/0x2e0 fs/proc/inode.c:320 vfs_read+0x1fd/0x980 fs/read_write.c:568 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 (&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 -> #3 (&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 -> #2 (&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_propagate+0x108/0x130 fs/nilfs2/bmap.c:332 nilfs_collect_file_data+0x4f/0xd0 fs/nilfs2/segment.c:589 nilfs_segctor_apply_buffers+0x161/0x330 fs/nilfs2/segment.c:1010 nilfs_segctor_scan_file+0x68e/0x8e0 fs/nilfs2/segment.c:1059 nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1254 [inline] nilfs_segctor_collect fs/nilfs2/segment.c:1547 [inline] nilfs_segctor_do_construct+0x1d46/0x6970 fs/nilfs2/segment.c:2122 nilfs_segctor_construct+0x17b/0x690 fs/nilfs2/segment.c:2478 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2586 [inline] nilfs_segctor_thread+0x6f7/0xe00 fs/nilfs2/segment.c:2700 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #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 new_sync_write fs/read_write.c:591 [inline] vfs_write+0x548/0xa90 fs/read_write.c:684 ksys_write+0x145/0x250 fs/read_write.c:736 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#7){.+.+}-{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 rep_movs_alternative+0x4a/0x90 arch/x86/lib/copy_user_64.S:68 copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline] copy_to_user_iter lib/iov_iter.c:25 [inline] iterate_iovec include/linux/iov_iter.h:52 [inline] iterate_and_advance2 include/linux/iov_iter.h:302 [inline] iterate_and_advance include/linux/iov_iter.h:328 [inline] _copy_to_iter+0x484/0x15a0 lib/iov_iter.c:185 copy_to_iter include/linux/uio.h:220 [inline] seq_read_iter+0xbeb/0xe10 fs/seq_file.c:281 seq_read+0x2e2/0x3d0 fs/seq_file.c:162 pde_read fs/proc/inode.c:308 [inline] proc_reg_read+0x1e6/0x2e0 fs/proc/inode.c:320 vfs_read+0x1fd/0x980 fs/read_write.c:568 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#7 --> &mm->mmap_lock --> sb_pagefaults#4 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(sb_pagefaults#4); lock(&mm->mmap_lock); lock(sb_pagefaults#4); rlock(sb_internal#7); *** DEADLOCK *** 4 locks held by syz.2.311/8899: #0: ffff8880117f47f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1213 #1: ffff88804f2abd58 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:182 #2: ffff8880206f1fe0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:203 [inline] #2: ffff8880206f1fe0 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/memory.c:6346 [inline] #2: ffff8880206f1fe0 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x32/0x300 mm/memory.c:6406 #3: ffff88802ffde518 (sb_pagefaults#4){.+.+}-{0:0}, at: do_page_mkwrite+0x14a/0x310 mm/memory.c:3287 stack backtrace: CPU: 1 UID: 0 PID: 8899 Comm: syz.2.311 Not tainted 6.15.0-rc5-syzkaller-00136-g9c69f8884904 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 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: 0010:rep_movs_alternative+0x4a/0x90 arch/x86/lib/copy_user_64.S:74 Code: cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 db 83 f9 08 73 e8 eb c5 a4 c3 cc cc cc cc 48 8b 06 48 89 07 48 8d 47 08 48 83 e0 f8 48 RSP: 0018:ffffc90004dcf8d8 EFLAGS: 00050202 RAX: ffffffff84af1701 RBX: ffff8880324e6000 RCX: 000000000000051d RDX: 0000000000000000 RSI: ffff8880324e6ac0 RDI: 0000200000001000 RBP: ffffc90004dcfa30 R08: ffff8880324e6fdc R09: 1ffff1100649cdfb R10: dffffc0000000000 R11: ffffed100649cdfc R12: dffffc0000000000 R13: 0000000000000000 R14: 00007ffffffff000 R15: 0000000000000fdd copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline] copy_to_user_iter lib/iov_iter.c:25 [inline] iterate_iovec include/linux/iov_iter.h:52 [inline] iterate_and_advance2 include/linux/iov_iter.h:302 [inline] iterate_and_advance include/linux/iov_iter.h:328 [inline] _copy_to_iter+0x484/0x15a0 lib/iov_iter.c:185 copy_to_iter include/linux/uio.h:220 [inline] seq_read_iter+0xbeb/0xe10 fs/seq_file.c:281 seq_read+0x2e2/0x3d0 fs/seq_file.c:162 pde_read fs/proc/inode.c:308 [inline] proc_reg_read+0x1e6/0x2e0 fs/proc/inode.c:320 vfs_read+0x1fd/0x980 fs/read_write.c:568 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: 0033:0x7f3d50b8e969 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:00007f3d51ab4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f3d50db5fa0 RCX: 00007f3d50b8e969 RDX: 0000000000002020 RSI: 0000200000000540 RDI: 0000000000000009 RBP: 00007f3d50c10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f3d50db5fa0 R15: 00007ffcc7b13508 NILFS (loop2): disposed unprocessed dirty file(s) when stopping log writer ---------------- Code disassembly (best guess): 0: cc int3 1: cc int3 2: cc int3 3: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) a: 00 00 00 d: 0f 1f 00 nopl (%rax) 10: 48 8b 06 mov (%rsi),%rax 13: 48 89 07 mov %rax,(%rdi) 16: 48 83 c6 08 add $0x8,%rsi 1a: 48 83 c7 08 add $0x8,%rdi 1e: 83 e9 08 sub $0x8,%ecx 21: 74 db je 0xfffffffe 23: 83 f9 08 cmp $0x8,%ecx 26: 73 e8 jae 0x10 28: eb c5 jmp 0xffffffef * 2a: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) <-- trapping instruction 2c: c3 ret 2d: cc int3 2e: cc int3 2f: cc int3 30: cc int3 31: 48 8b 06 mov (%rsi),%rax 34: 48 89 07 mov %rax,(%rdi) 37: 48 8d 47 08 lea 0x8(%rdi),%rax 3b: 48 83 e0 f8 and $0xfffffffffffffff8,%rax 3f: 48 rex.W