[syzbot] [ntfs3?] possible deadlock in attr_data_get_block (2)

syzbot
2024-08-15T10:46:25Z

Hello,

syzbot found the following issue on:

HEAD commit: 9d5906799f7d Merge tag 'selinux-pr-20240814' of git://git...
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1673c7d3980000
kernel config: https://syzkaller.appspot.com/x/.config?x=92c0312151c4e32e
dashboard link: https://syzkaller.appspot.com/bug?extid=262a71e9d2faf8747085
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=109e7cfd980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=129e6c05980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/446819619a5c/disk-9d590679.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/14a59529d386/vmlinux-9d590679.xz
kernel image: https://storage.googleapis.com/syzbot-assets/04e89692a4c8/bzImage-9d590679.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/c9e039126cae/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+262a71e9d2faf8747085@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
6.11.0-rc3-syzkaller-00036-g9d5906799f7d #0 Not tainted
------------------------------------------------------
syz-executor969/5214 is trying to acquire lock:
ffff8880788e6f28 (&ni->ni_lock/4){+.+.}-{3:3}, at: ni_lock fs/ntfs3/ntfs_fs.h:1110 [inline]
ffff8880788e6f28 (&ni->ni_lock/4){+.+.}-{3:3}, at: attr_data_get_block+0x463/0x2ff0 fs/ntfs3/attrib.c:917

but task is already holding lock:
ffff888015579e18 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:122 [inline]
ffff888015579e18 (&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
__might_fault+0xc6/0x120 mm/memory.c:6388
_inline_copy_to_user include/linux/uaccess.h:176 [inline]
_copy_to_user+0x2a/0xb0 lib/usercopy.c:26
copy_to_user include/linux/uaccess.h:209 [inline]
fiemap_fill_next_extent+0x235/0x410 fs/ioctl.c:145
ni_fiemap+0x4f5/0x1910 fs/ntfs3/frecord.c:1993
ntfs_fiemap+0x132/0x180 fs/ntfs3/file.c:1279
ioctl_fiemap fs/ioctl.c:220 [inline]
do_vfs_ioctl+0x1c07/0x2e50 fs/ioctl.c:841
__do_sys_ioctl fs/ioctl.c:905 [inline]
__se_sys_ioctl+0x81/0x170 fs/ioctl.c:893
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 (&ni->ni_lock/4){+.+.}-{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
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
ni_lock fs/ntfs3/ntfs_fs.h:1110 [inline]
attr_data_get_block+0x463/0x2ff0 fs/ntfs3/attrib.c:917
ntfs_file_mmap+0x4f5/0x850 fs/ntfs3/file.c:360
call_mmap include/linux/fs.h:2129 [inline]
mmap_region+0xe8f/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(&ni->ni_lock/4);
lock(&mm->mmap_lock);
lock(&ni->ni_lock/4);

*** DEADLOCK ***

1 lock held by syz-executor969/5214:
#0: ffff888015579e18 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:122 [inline]
#0: ffff888015579e18 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x17c/0x3d0 mm/util.c:586

stack backtrace:
CPU: 1 UID: 0 PID: 5214 Comm: syz-executor969 Not tainted 6.11.0-rc3-syzkaller-00036-g9d5906799f7d #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
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
ni_lock fs/ntfs3/ntfs_fs.h:1110 [inline]
attr_data_get_block+0x463/0x2ff0 fs/ntfs3/attrib.c:917
ntfs_file_mmap+0x4f5/0x850 fs/ntfs3/file.c:360
call_mmap include/linux/fs.h:2129 [inline]
mmap_region+0xe8f/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: 0033:0x7f387a5eebd9
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:00007ffc3dce7448 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f387a5eebd9
RDX: 00000000027fffff RSI: 0000000000600000 RDI: 0000000020000000
RBP: 00007f387a6815f0 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000004002011 R11: 0000000000000246 R12: 00007ffc3dce7480
R13: 00007ffc3dce76a8 R14: 431bde82d7b634db R15: 00007f387a63703b
</TASK>

---
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