loop2: detected capacity change from 0 to 4096
======================================================
WARNING: possible circular locking dependency detected
6.16.0-rc2-syzkaller-00162-g41687a5c6f8b #0 Not tainted
------------------------------------------------------
syz.2.5760/21909 is trying to acquire lock:
ffff888033a16d60 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock_killable include/linux/mmap_lock.h:421 [inline]
ffff888033a16d60 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/mmap_lock.c:197 [inline]
ffff888033a16d60 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x3e7/0x6e0 mm/mmap_lock.c:248
but task is already holding lock:
ffff88804bfe9248 (&sb->s_type->i_mutex_key#28){+.+.}-{4:4}, at: inode_trylock include/linux/fs.h:899 [inline]
ffff88804bfe9248 (&sb->s_type->i_mutex_key#28){+.+.}-{4:4}, at: ntfs_file_write_iter+0xdf/0x2120 fs/ntfs3/file.c:1160
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&sb->s_type->i_mutex_key#28){+.+.}-{4:4}:
down_write+0x92/0x200 kernel/locking/rwsem.c:1577
inode_lock include/linux/fs.h:869 [inline]
ntfs_file_mmap+0x60c/0x780 fs/ntfs3/file.c:313
call_mmap include/linux/fs.h:2286 [inline]
mmap_file mm/internal.h:167 [inline]
__mmap_new_file_vma mm/vma.c:2405 [inline]
__mmap_new_vma mm/vma.c:2467 [inline]
__mmap_region+0x128e/0x25e0 mm/vma.c:2622
mmap_region+0x32b/0x3f0 mm/vma.c:2692
do_mmap+0xa3e/0x1210 mm/mmap.c:561
vm_mmap_pgoff+0x281/0x450 mm/util.c:579
ksys_mmap_pgoff+0x32c/0x5c0 mm/mmap.c:607
__do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
__se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
__x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (&mm->mmap_lock){++++}-{4:4}:
check_prev_add kernel/locking/lockdep.c:3168 [inline]
check_prevs_add kernel/locking/lockdep.c:3287 [inline]
validate_chain kernel/locking/lockdep.c:3911 [inline]
__lock_acquire+0x126f/0x1c90 kernel/locking/lockdep.c:5240
lock_acquire kernel/locking/lockdep.c:5871 [inline]
lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5828
down_read_killable+0x9e/0x4b0 kernel/locking/rwsem.c:1547
mmap_read_lock_killable include/linux/mmap_lock.h:421 [inline]
get_mmap_lock_carefully mm/mmap_lock.c:197 [inline]
lock_mm_and_find_vma+0x3e7/0x6e0 mm/mmap_lock.c:248
do_user_addr_fault+0x2ac/0x1370 arch/x86/mm/fault.c:1359
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x5c/0xb0 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
fault_in_readable+0x135/0x1d0 mm/gup.c:2227
fault_in_iov_iter_readable+0x101/0x2c0 lib/iov_iter.c:94
generic_perform_write+0x7b4/0x930 mm/filemap.c:4161
__generic_file_write_iter+0x1f7/0x240 mm/filemap.c:4229
ntfs_file_write_iter+0xed3/0x2120 fs/ntfs3/file.c:1197
do_iter_readv_writev+0x657/0x950 fs/read_write.c:827
vfs_writev+0x35f/0xde0 fs/read_write.c:1057
do_pwritev+0x1a6/0x270 fs/read_write.c:1153
__do_sys_pwritev2 fs/read_write.c:1211 [inline]
__se_sys_pwritev2 fs/read_write.c:1202 [inline]
__x64_sys_pwritev2+0xef/0x160 fs/read_write.c:1202
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&sb->s_type->i_mutex_key#28);
lock(&mm->mmap_lock);
lock(&sb->s_type->i_mutex_key#28);
rlock(&mm->mmap_lock);
*** DEADLOCK ***
2 locks held by syz.2.5760/21909:
#0: ffff8880364a6428 (sb_writers#21){.+.+}-{0:0}, at: do_pwritev+0x1a6/0x270 fs/read_write.c:1153
#1: ffff88804bfe9248 (&sb->s_type->i_mutex_key#28){+.+.}-{4:4}, at: inode_trylock include/linux/fs.h:899 [inline]
#1: ffff88804bfe9248 (&sb->s_type->i_mutex_key#28){+.+.}-{4:4}, at: ntfs_file_write_iter+0xdf/0x2120 fs/ntfs3/file.c:1160
stack backtrace:
CPU: 1 UID: 0 PID: 21909 Comm: syz.2.5760 Not tainted 6.16.0-rc2-syzkaller-00162-g41687a5c6f8b #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
<TASK>
__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:2046
check_noncircular+0x14c/0x170 kernel/locking/lockdep.c:2178
check_prev_add kernel/locking/lockdep.c:3168 [inline]
check_prevs_add kernel/locking/lockdep.c:3287 [inline]
validate_chain kernel/locking/lockdep.c:3911 [inline]
__lock_acquire+0x126f/0x1c90 kernel/locking/lockdep.c:5240
lock_acquire kernel/locking/lockdep.c:5871 [inline]
lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5828
down_read_killable+0x9e/0x4b0 kernel/locking/rwsem.c:1547
mmap_read_lock_killable include/linux/mmap_lock.h:421 [inline]
get_mmap_lock_carefully mm/mmap_lock.c:197 [inline]
lock_mm_and_find_vma+0x3e7/0x6e0 mm/mmap_lock.c:248
do_user_addr_fault+0x2ac/0x1370 arch/x86/mm/fault.c:1359
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x5c/0xb0 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0010:fault_in_readable+0x135/0x1d0 mm/gup.c:2227
Code: e1 a5 b7 ff 48 85 db 0f 84 9c 00 00 00 e8 63 aa b7 ff 48 89 de 48 89 ef e8 08 a5 b7 ff 48 39 eb 73 1d e8 4e aa b7 ff 45 89 f7 <8a> 03 31 ff 44 89 fe 88 44 24 28 e8 7b a5 b7 ff 45 85 ff 74 a8 e8
RSP: 0018:ffffc9000ec8f790 EFLAGS: 00050283
RAX: 000000000000c6a4 RBX: 000020000000c000 RCX: ffffc9000c7cb000
RDX: 0000000000080000 RSI: ffffffff82047132 RDI: 0000000000000006
RBP: 000020000000c205 R08: 0000000000000006 R09: 000020000000c000
R10: 000020000000c205 R11: 0000000000000000 R12: 000020000000c000
R13: 0000000000000205 R14: 0000000000000000 R15: 0000000000000000
fault_in_iov_iter_readable+0x101/0x2c0 lib/iov_iter.c:94
generic_perform_write+0x7b4/0x930 mm/filemap.c:4161
__generic_file_write_iter+0x1f7/0x240 mm/filemap.c:4229
ntfs_file_write_iter+0xed3/0x2120 fs/ntfs3/file.c:1197
do_iter_readv_writev+0x657/0x950 fs/read_write.c:827
vfs_writev+0x35f/0xde0 fs/read_write.c:1057
do_pwritev+0x1a6/0x270 fs/read_write.c:1153
__do_sys_pwritev2 fs/read_write.c:1211 [inline]
__se_sys_pwritev2 fs/read_write.c:1202 [inline]
__x64_sys_pwritev2+0xef/0x160 fs/read_write.c:1202
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fda19f8e929
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:00007fda1ae4e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000148
RAX: ffffffffffffffda RBX: 00007fda1a1b5fa0 RCX: 00007fda19f8e929
RDX: 0000000000000001 RSI: 00002000000001c0 RDI: 0000000000000004
RBP: 00007fda1a010b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000e7b R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fda1a1b5fa0 R15: 00007ffeaa9ebf48
</TASK>
----------------
Code disassembly (best guess):
0: e1 a5 loope 0xffffffa7
2: b7 ff mov $0xff,%bh
4: 48 85 db test %rbx,%rbx
7: 0f 84 9c 00 00 00 je 0xa9
d: e8 63 aa b7 ff call 0xffb7aa75
12: 48 89 de mov %rbx,%rsi
15: 48 89 ef mov %rbp,%rdi
18: e8 08 a5 b7 ff call 0xffb7a525
1d: 48 39 eb cmp %rbp,%rbx
20: 73 1d jae 0x3f
22: e8 4e aa b7 ff call 0xffb7aa75
27: 45 89 f7 mov %r14d,%r15d
* 2a: 8a 03 mov (%rbx),%al <-- trapping instruction
2c: 31 ff xor %edi,%edi
2e: 44 89 fe mov %r15d,%esi
31: 88 44 24 28 mov %al,0x28(%rsp)
35: e8 7b a5 b7 ff call 0xffb7a5b5
3a: 45 85 ff test %r15d,%r15d
3d: 74 a8 je 0xffffffe7
3f: e8 .byte 0xe8