Re: [syzbot] [ntfs3?] possible deadlock in ntfs_file_mmap

syzbot
2024-07-27T13:44:21Z

syzbot has found a reproducer for the following issue on:

HEAD commit: 2f8c4f506285 Merge tag 'auxdisplay-for-v6.11-tag1' of git:..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=10836f19980000
kernel config: https://syzkaller.appspot.com/x/.config?x=5efb917b1462a973
dashboard link: https://syzkaller.appspot.com/bug?extid=c1751b6739d83d70bb75
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=108328d9980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12e875a1980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/beafa5a4d4f9/disk-2f8c4f50.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e58aee7103bd/vmlinux-2f8c4f50.xz
kernel image: https://storage.googleapis.com/syzbot-assets/92d87af85377/bzImage-2f8c4f50.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/ed5b83574e49/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c1751b6739d83d70bb75@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
6.10.0-syzkaller-12708-g2f8c4f506285 #0 Not tainted
------------------------------------------------------
syz-executor114/5223 is trying to acquire lock:
ffff888073150af0 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:799 [inline]
ffff888073150af0 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}, at: ntfs_file_mmap+0x5bf/0x850 fs/ntfs3/file.c:368

but task is already holding lock:
ffff88807dfbf398 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:122 [inline]
ffff88807dfbf398 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x17c/0x3d0 mm/util.c:586

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&mm->mmap_lock){++++}-{3:3}:
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
gup_fast_fallback+0x24c/0x2b50 mm/gup.c:3367
pin_user_pages_fast+0xcc/0x160 mm/gup.c:3491
iov_iter_extract_user_pages lib/iov_iter.c:1583 [inline]
iov_iter_extract_pages+0x3db/0x720 lib/iov_iter.c:1646
dio_refill_pages fs/direct-io.c:173 [inline]
dio_get_page fs/direct-io.c:214 [inline]
do_direct_IO fs/direct-io.c:916 [inline]
__blockdev_direct_IO+0x144c/0x4890 fs/direct-io.c:1249
blockdev_direct_IO include/linux/fs.h:3212 [inline]
ntfs_direct_IO+0x195/0x370 fs/ntfs3/inode.c:801
generic_file_direct_write+0x132/0x350 mm/filemap.c:3941
__generic_file_write_iter+0x129/0x230 mm/filemap.c:4107
ntfs_file_write_iter+0x663/0x740 fs/ntfs3/file.c:1193
do_iter_readv_writev+0x60c/0x890
vfs_writev+0x37c/0xbb0 fs/read_write.c:971
do_pwritev fs/read_write.c:1072 [inline]
__do_sys_pwritev2 fs/read_write.c:1131 [inline]
__se_sys_pwritev2+0x1ca/0x2d0 fs/read_write.c:1122
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3133 [inline]
check_prevs_add kernel/locking/lockdep.c:3252 [inline]
validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868
__lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
down_write+0x99/0x220 kernel/locking/rwsem.c:1579
inode_lock include/linux/fs.h:799 [inline]
ntfs_file_mmap+0x5bf/0x850 fs/ntfs3/file.c:368
call_mmap include/linux/fs.h:2129 [inline]
mmap_region+0xe91/0x2090 mm/mmap.c:2957
do_mmap+0x8f9/0x1010 mm/mmap.c:1468
vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:588
ksys_mmap_pgoff+0x4f1/0x720 mm/mmap.c:1514
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&mm->mmap_lock);
lock(&sb->s_type->i_mutex_key#15);
lock(&mm->mmap_lock);
lock(&sb->s_type->i_mutex_key#15);

*** DEADLOCK ***

1 lock held by syz-executor114/5223:
#0: ffff88807dfbf398 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:122 [inline]
#0: ffff88807dfbf398 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x17c/0x3d0 mm/util.c:586

stack backtrace:
CPU: 0 UID: 0 PID: 5223 Comm: syz-executor114 Not tainted 6.10.0-syzkaller-12708-g2f8c4f506285 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:93 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2186
check_prev_add kernel/locking/lockdep.c:3133 [inline]
check_prevs_add kernel/locking/lockdep.c:3252 [inline]
validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868
__lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
down_write+0x99/0x220 kernel/locking/rwsem.c:1579
inode_lock include/linux/fs.h:799 [inline]
ntfs_file_mmap+0x5bf/0x850 fs/ntfs3/file.c:368
call_mmap include/linux/fs.h:2129 [inline]
mmap_region+0xe91/0x2090 mm/mmap.c:2957
do_mmap+0x8f9/0x1010 mm/mmap.c:1468
vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:588
ksys_mmap_pgoff+0x4f1/0x720 mm/mmap.c:1514
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f71d1735e19
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffbfcbe088 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f71d1735e19
RDX: 00000000007fffff RSI: 0000000000003000 RDI: 0000000020000000
RBP: 00007f71d17c95f0 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000012 R11: 0000000000000246 R12: 00007fffbfcbe0c0
R13: 00007fffbfcbe2e8 R14: 431bde82d7b634db R15: 00007f71d177f03b
</TASK>

---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.