NILFS (loop4): trying rollback from an earlier position NILFS (loop4): recovery complete ====================================================== WARNING: possible circular locking dependency detected 6.15.0-rc3-syzkaller-00283-gf1a3944c860b #0 Not tainted ------------------------------------------------------ syz.4.315/6935 is trying to acquire lock: ffff8880127c0610 (sb_internal#5){.+.+}-{0:0}, at: nilfs_page_mkwrite+0x963/0xcd0 fs/nilfs2/file.c:95 but task is already holding lock: ffff8880127c0518 (sb_pagefaults#2){.+.+}-{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#2){.+.+}-{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 wp_page_shared mm/memory.c:3688 [inline] do_wp_page+0xb9e/0x58e0 mm/memory.c:3907 handle_pte_fault mm/memory.c:6013 [inline] __handle_mm_fault+0x1ada/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 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_ubuf include/linux/iov_iter.h:30 [inline] iterate_and_advance2 include/linux/iov_iter.h:300 [inline] iterate_and_advance include/linux/iov_iter.h:328 [inline] _copy_to_iter+0x38c/0x15a0 lib/iov_iter.c:185 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 generic_file_read_iter+0x344/0x450 mm/filemap.c:2894 do_iter_readv_writev+0x738/0x950 fs/read_write.c:823 vfs_readv+0x4c5/0x8a0 fs/read_write.c:1016 do_preadv+0x1af/0x270 fs/read_write.c:1130 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 -> #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_propagate+0x131/0x170 fs/nilfs2/bmap.c:332 nilfs_collect_file_data+0x49/0xd0 fs/nilfs2/segment.c:589 nilfs_segctor_apply_buffers+0x14d/0x480 fs/nilfs2/segment.c:1010 nilfs_segctor_scan_file+0x3f7/0x700 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+0xec4/0x8220 fs/nilfs2/segment.c:2122 nilfs_segctor_construct+0x748/0x900 fs/nilfs2/segment.c:2478 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2586 [inline] nilfs_segctor_thread+0x650/0xa60 fs/nilfs2/segment.c:2700 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x48/0x80 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}: down_read+0x9b/0x480 kernel/locking/rwsem.c:1524 nilfs_transaction_begin+0x326/0xa40 fs/nilfs2/segment.c:221 nilfs_create+0xb6/0x320 fs/nilfs2/namei.c:95 lookup_open.isra.0+0x11d3/0x1580 fs/namei.c:3701 open_last_lookups fs/namei.c:3800 [inline] path_openat+0x905/0x2d40 fs/namei.c:4036 do_filp_open+0x20b/0x470 fs/namei.c:4066 do_sys_openat2+0x11b/0x1d0 fs/open.c:1429 do_sys_open fs/open.c:1444 [inline] __do_sys_openat fs/open.c:1460 [inline] __se_sys_openat fs/open.c:1455 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1455 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#5){.+.+}-{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 wp_page_shared mm/memory.c:3688 [inline] do_wp_page+0xb9e/0x58e0 mm/memory.c:3907 handle_pte_fault mm/memory.c:6013 [inline] __handle_mm_fault+0x1ada/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 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] _inline_copy_to_user include/linux/uaccess.h:197 [inline] _copy_to_user+0xb6/0xd0 lib/usercopy.c:26 copy_to_user include/linux/uaccess.h:225 [inline] ioctl_fiemap fs/ioctl.c:225 [inline] do_vfs_ioctl+0x424/0x1990 fs/ioctl.c:840 __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x11d/0x200 fs/ioctl.c:892 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 other info that might help us debug this: Chain exists of: sb_internal#5 --> &mm->mmap_lock --> sb_pagefaults#2 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(sb_pagefaults#2); lock(&mm->mmap_lock); lock(sb_pagefaults#2); rlock(sb_internal#5); *** DEADLOCK *** 2 locks held by syz.4.315/6935: #0: ffff888041ead1e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:203 [inline] #0: ffff888041ead1e0 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/memory.c:6346 [inline] #0: ffff888041ead1e0 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x35/0x6e0 mm/memory.c:6406 #1: ffff8880127c0518 (sb_pagefaults#2){.+.+}-{0:0}, at: do_page_mkwrite+0x174/0x380 mm/memory.c:3287 stack backtrace: CPU: 1 UID: 0 PID: 6935 Comm: syz.4.315 Not tainted 6.15.0-rc3-syzkaller-00283-gf1a3944c860b #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 wp_page_shared mm/memory.c:3688 [inline] do_wp_page+0xb9e/0x58e0 mm/memory.c:3907 handle_pte_fault mm/memory.c:6013 [inline] __handle_mm_fault+0x1ada/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: 0010:copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline] RIP: 0010:raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline] RIP: 0010:_inline_copy_to_user include/linux/uaccess.h:197 [inline] RIP: 0010:_copy_to_user+0xb6/0xd0 lib/usercopy.c:26 Code: 89 ee 48 89 ef e8 7a a7 ec fc 4d 85 ff 75 a8 e8 c0 ac ec fc 89 de 4c 89 e7 e8 06 3a 51 fd 0f 01 cb 48 89 d9 48 89 ef 4c 89 e6 a4 0f 1f 00 0f 01 ca 48 89 cb eb 80 66 2e 0f 1f 84 00 00 00 00 RSP: 0018:ffffc900031f7c90 EFLAGS: 00050246 RAX: 0000000000000001 RBX: 0000000000000020 RCX: 0000000000000020 RDX: fffff5200063efcf RSI: ffffc900031f7e58 RDI: 0000200000000280 RBP: 0000200000000280 R08: 0000000000000000 R09: fffff5200063efce R10: ffffc900031f7e77 R11: 0000000000000000 R12: ffffc900031f7e58 R13: 00002000000002a0 R14: 00007ffffffff000 R15: 0000000000000000 copy_to_user include/linux/uaccess.h:225 [inline] ioctl_fiemap fs/ioctl.c:225 [inline] do_vfs_ioctl+0x424/0x1990 fs/ioctl.c:840 __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x11d/0x200 fs/ioctl.c:892 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 RIP: 0033:0x7fed12d8e969 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:00007fed13c8f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fed12fb5fa0 RCX: 00007fed12d8e969 RDX: 0000200000000280 RSI: 00000000c020660b RDI: 0000000000000004 RBP: 00007fed12e10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fed12fb5fa0 R15: 00007fff35916f48 ---------------- Code disassembly (best guess): 0: 89 ee mov %ebp,%esi 2: 48 89 ef mov %rbp,%rdi 5: e8 7a a7 ec fc call 0xfceca784 a: 4d 85 ff test %r15,%r15 d: 75 a8 jne 0xffffffb7 f: e8 c0 ac ec fc call 0xfcecacd4 14: 89 de mov %ebx,%esi 16: 4c 89 e7 mov %r12,%rdi 19: e8 06 3a 51 fd call 0xfd513a24 1e: 0f 01 cb stac 21: 48 89 d9 mov %rbx,%rcx 24: 48 89 ef mov %rbp,%rdi 27: 4c 89 e6 mov %r12,%rsi * 2a: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) <-- trapping instruction 2c: 0f 1f 00 nopl (%rax) 2f: 0f 01 ca clac 32: 48 89 cb mov %rcx,%rbx 35: eb 80 jmp 0xffffffb7 37: 66 data16 38: 2e cs 39: 0f .byte 0xf 3a: 1f (bad) 3b: 84 00 test %al,(%rax) 3d: 00 00 add %al,(%rax)