====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.0.33/5970 is trying to acquire lock: ffff88802a63dcf8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock_killable+0x1d/0x70 include/linux/mmap_lock.h:609 but task is already holding lock: ffff888055cfd5b8 (&ni->ni_lock#2/5){+.+.}-{4:4}, at: ni_lock fs/ntfs3/ntfs_fs.h:1247 [inline] ffff888055cfd5b8 (&ni->ni_lock#2/5){+.+.}-{4:4}, at: ntfs_readdir+0x70e/0xf60 fs/ntfs3/dir.c:541 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&ni->ni_lock#2/5){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x19c/0x15a0 kernel/locking/mutex.c:821 ni_lock fs/ntfs3/ntfs_fs.h:1247 [inline] attr_data_get_block+0x1cd/0x2c0 fs/ntfs3/attrib.c:976 ntfs_file_mmap_prepare+0x5b0/0xa20 fs/ntfs3/file.c:430 vfs_mmap_prepare include/linux/fs.h:2069 [inline] call_mmap_prepare mm/vma.c:2776 [inline] __mmap_region mm/vma.c:2863 [inline] mmap_region+0xe8a/0x2240 mm/vma.c:2964 do_mmap+0xe0a/0x1300 mm/mmap.c:573 vm_mmap_pgoff+0x272/0x4e0 mm/util.c:581 ksys_mmap_pgoff+0x4dc/0x760 mm/mmap.c:619 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&mm->mmap_lock){++++}-{4:4}: check_prev_add kernel/locking/lockdep.c:3181 [inline] check_prevs_add kernel/locking/lockdep.c:3300 [inline] validate_chain kernel/locking/lockdep.c:3924 [inline] __lock_acquire+0x15ff/0x2e50 kernel/locking/lockdep.c:5254 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5908 down_read_killable+0x50/0x3b0 kernel/locking/rwsem.c:1599 mmap_read_lock_killable+0x1d/0x70 include/linux/mmap_lock.h:609 get_mmap_lock_carefully mm/mmap_lock.c:450 [inline] lock_mm_and_find_vma+0x2d6/0x340 mm/mmap_lock.c:501 do_user_addr_fault+0x33e/0x1480 arch/x86/mm/fault.c:1366 handle_page_fault arch/x86/mm/fault.c:1483 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 stac arch/x86/include/asm/smap.h:-1 [inline] filldir+0x293/0x690 fs/readdir.c:286 dir_emit include/linux/fs.h:3607 [inline] ntfs_dir_emit fs/ntfs3/dir.c:388 [inline] ntfs_read_hdr+0x8a7/0xc10 fs/ntfs3/dir.c:429 ntfs_readdir+0x9a2/0xf60 fs/ntfs3/dir.c:589 iterate_dir+0x2e2/0x4d0 fs/readdir.c:110 __do_sys_getdents fs/readdir.c:319 [inline] __se_sys_getdents+0xf1/0x270 fs/readdir.c:304 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ni->ni_lock#2/5); lock(&mm->mmap_lock); lock(&ni->ni_lock#2/5); rlock(&mm->mmap_lock); *** DEADLOCK *** locks held by syz.0.33/5970: 3, last CPU#0: #0: ffff888079516ef0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1259 #1: ffff888055cfd850 (&type->i_mutex_dir_key#8){.+.+}-{4:4}, at: iterate_dir+0x209/0x4d0 fs/readdir.c:103 #2: ffff888055cfd5b8 (&ni->ni_lock#2/5){+.+.}-{4:4}, at: ni_lock fs/ntfs3/ntfs_fs.h:1247 [inline] #2: ffff888055cfd5b8 (&ni->ni_lock#2/5){+.+.}-{4:4}, at: ntfs_readdir+0x70e/0xf60 fs/ntfs3/dir.c:541 stack backtrace: CPU: 0 UID: 0 PID: 5970 Comm: syz.0.33 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2059 check_noncircular+0x12f/0x150 kernel/locking/lockdep.c:2191 check_prev_add kernel/locking/lockdep.c:3181 [inline] check_prevs_add kernel/locking/lockdep.c:3300 [inline] validate_chain kernel/locking/lockdep.c:3924 [inline] __lock_acquire+0x15ff/0x2e50 kernel/locking/lockdep.c:5254 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5908 down_read_killable+0x50/0x3b0 kernel/locking/rwsem.c:1599 mmap_read_lock_killable+0x1d/0x70 include/linux/mmap_lock.h:609 get_mmap_lock_carefully mm/mmap_lock.c:450 [inline] lock_mm_and_find_vma+0x2d6/0x340 mm/mmap_lock.c:501 do_user_addr_fault+0x33e/0x1480 arch/x86/mm/fault.c:1366 handle_page_fault arch/x86/mm/fault.c:1483 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0010:filldir+0x293/0x690 fs/readdir.c:288 Code: fd 48 29 d5 48 b8 00 f0 ff ff ff 7f 00 00 48 39 c5 48 0f 47 e8 bf 07 00 00 00 44 89 f6 e8 75 2d 76 ff 0f 01 cb 48 8b 44 24 30 <48> 89 45 08 48 8b 44 24 08 49 89 07 49 8d 47 10 48 bd 00 00 00 00 RSP: 0018:ffffc90004fd7ab8 EFLAGS: 00050297 RAX: 00000000000014c0 RBX: ffffc90004fd7e38 RCX: ffff888021b3be80 RDX: 0000000000000002 RSI: 0000000000000015 RDI: 0000000000000007 RBP: 0000200000001fc0 R08: 0000000000000021 R09: 0000000000000008 R10: dffffc0000000000 R11: ffffffff8251a4a0 R12: ffff88807a700000 R13: 0000000000000015 R14: 0000000000000015 R15: 0000200000001fc0 dir_emit include/linux/fs.h:3607 [inline] ntfs_dir_emit fs/ntfs3/dir.c:388 [inline] ntfs_read_hdr+0x8a7/0xc10 fs/ntfs3/dir.c:429 ntfs_readdir+0x9a2/0xf60 fs/ntfs3/dir.c:589 iterate_dir+0x2e2/0x4d0 fs/readdir.c:110 __do_sys_getdents fs/readdir.c:319 [inline] __se_sys_getdents+0xf1/0x270 fs/readdir.c:304 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff7b6b9e159 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff7b7a35028 EFLAGS: 00000246 ORIG_RAX: 000000000000004e RAX: ffffffffffffffda RBX: 00007ff7b6e26090 RCX: 00007ff7b6b9e159 RDX: 00000000000000b8 RSI: 0000200000001fc0 RDI: 0000000000000005 RBP: 00007ff7b6c35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff7b6e26128 R14: 00007ff7b6e26090 R15: 00007ffc16d60188 ---------------- Code disassembly (best guess): 0: fd std 1: 48 29 d5 sub %rdx,%rbp 4: 48 b8 00 f0 ff ff ff movabs $0x7ffffffff000,%rax b: 7f 00 00 e: 48 39 c5 cmp %rax,%rbp 11: 48 0f 47 e8 cmova %rax,%rbp 15: bf 07 00 00 00 mov $0x7,%edi 1a: 44 89 f6 mov %r14d,%esi 1d: e8 75 2d 76 ff call 0xff762d97 22: 0f 01 cb stac 25: 48 8b 44 24 30 mov 0x30(%rsp),%rax * 2a: 48 89 45 08 mov %rax,0x8(%rbp) <-- trapping instruction 2e: 48 8b 44 24 08 mov 0x8(%rsp),%rax 33: 49 89 07 mov %rax,(%r15) 36: 49 8d 47 10 lea 0x10(%r15),%rax 3a: 48 rex.W 3b: bd 00 00 00 00 mov $0x0,%ebp