syzbot


possible deadlock in ntfs_set_size (3)

Status: upstream: reported on 2024/10/09 19:06
Subsystems: ntfs3
[Documentation on labels]
Reported-by: syzbot+bc7ded2e21137a228c72@syzkaller.appspotmail.com
First crash: 45d, last: 5d10h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [ntfs3?] possible deadlock in ntfs_set_size (3) 0 (1) 2024/10/09 19:06
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in ntfs_set_size ntfs3 1 369d 365d 0/28 auto-obsoleted due to no activity on 2024/02/26 05:10
upstream possible deadlock in ntfs_set_size (2) ntfs3 1 180d 176d 0/28 auto-obsoleted due to no activity on 2024/09/01 20:31

Sample crash report:
loop5: detected capacity change from 0 to 4096
======================================================
WARNING: possible circular locking dependency detected
6.12.0-rc7-syzkaller-00187-gf868cd251776 #0 Not tainted
------------------------------------------------------
syz.5.348/8255 is trying to acquire lock:
ffff888058f10858 (&ni->ni_lock#3/5){+.+.}-{3:3}, at: ni_lock fs/ntfs3/ntfs_fs.h:1109 [inline]
ffff888058f10858 (&ni->ni_lock#3/5){+.+.}-{3:3}, at: ntfs_set_size+0x12e/0x200 fs/ntfs3/inode.c:851

but task is already holding lock:
ffff888058f10af0 (&sb->s_type->i_mutex_key#31){+.+.}-{3:3}, at: inode_trylock include/linux/fs.h:835 [inline]
ffff888058f10af0 (&sb->s_type->i_mutex_key#31){+.+.}-{3:3}, at: ntfs_file_write_iter+0x291/0x7a0 fs/ntfs3/file.c:1232

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&sb->s_type->i_mutex_key#31){+.+.}-{3:3}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       down_write+0x99/0x220 kernel/locking/rwsem.c:1577
       inode_lock include/linux/fs.h:815 [inline]
       ntfs_file_mmap+0x5bc/0x850 fs/ntfs3/file.c:377
       call_mmap include/linux/fs.h:2172 [inline]
       mmap_file mm/internal.h:123 [inline]
       __mmap_region mm/mmap.c:1453 [inline]
       mmap_region+0x1a2a/0x23f0 mm/mmap.c:1603
       do_mmap+0x8f0/0x1000 mm/mmap.c:496
       vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:588
       ksys_mmap_pgoff+0x4eb/0x720 mm/mmap.c:542
       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

-> #1 (&mm->mmap_lock){++++}-{3:3}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       __might_fault+0xc6/0x120 mm/memory.c:6716
       _inline_copy_to_user include/linux/uaccess.h:192 [inline]
       _copy_to_user+0x2c/0xb0 lib/usercopy.c:26
       copy_to_user include/linux/uaccess.h:225 [inline]
       ni_fiemap+0x57c/0x18c0 fs/ntfs3/frecord.c:2139
       ntfs_fiemap+0x132/0x180 fs/ntfs3/file.c:1352
       ioctl_fiemap fs/ioctl.c:220 [inline]
       do_vfs_ioctl+0x1bf8/0x2e40 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#3/5){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3161 [inline]
       check_prevs_add kernel/locking/lockdep.c:3280 [inline]
       validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
       __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       __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:1109 [inline]
       ntfs_set_size+0x12e/0x200 fs/ntfs3/inode.c:851
       ntfs_extend+0x1d1/0xad0 fs/ntfs3/file.c:407
       ntfs_file_write_iter+0x403/0x7a0 fs/ntfs3/file.c:1254
       new_sync_write fs/read_write.c:590 [inline]
       vfs_write+0xaeb/0xd30 fs/read_write.c:683
       ksys_write+0x183/0x2b0 fs/read_write.c:736
       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:

Chain exists of:
  &ni->ni_lock#3/5 --> &mm->mmap_lock --> &sb->s_type->i_mutex_key#31

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&sb->s_type->i_mutex_key#31);
                               lock(&mm->mmap_lock);
                               lock(&sb->s_type->i_mutex_key#31);
  lock(&ni->ni_lock#3/5);

 *** DEADLOCK ***

3 locks held by syz.5.348/8255:
 #0: ffff88806c1597b8 (&f->f_pos_lock){+.+.}-{3:3}, at: fdget_pos+0x24e/0x320 fs/file.c:1160
 #1: ffff888034ece420 (sb_writers#17){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #1: ffff888034ece420 (sb_writers#17){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:679
 #2: ffff888058f10af0 (&sb->s_type->i_mutex_key#31){+.+.}-{3:3}, at: inode_trylock include/linux/fs.h:835 [inline]
 #2: ffff888058f10af0 (&sb->s_type->i_mutex_key#31){+.+.}-{3:3}, at: ntfs_file_write_iter+0x291/0x7a0 fs/ntfs3/file.c:1232

stack backtrace:
CPU: 1 UID: 0 PID: 8255 Comm: syz.5.348 Not tainted 6.12.0-rc7-syzkaller-00187-gf868cd251776 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206
 check_prev_add kernel/locking/lockdep.c:3161 [inline]
 check_prevs_add kernel/locking/lockdep.c:3280 [inline]
 validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
 __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:1109 [inline]
 ntfs_set_size+0x12e/0x200 fs/ntfs3/inode.c:851
 ntfs_extend+0x1d1/0xad0 fs/ntfs3/file.c:407
 ntfs_file_write_iter+0x403/0x7a0 fs/ntfs3/file.c:1254
 new_sync_write fs/read_write.c:590 [inline]
 vfs_write+0xaeb/0xd30 fs/read_write.c:683
 ksys_write+0x183/0x2b0 fs/read_write.c:736
 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: 0033:0x7fdc4cb7e719
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:00007fdc4d9f3038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fdc4cd35f80 RCX: 00007fdc4cb7e719
RDX: 000000000f642e7e RSI: 0000000020000200 RDI: 0000000000000004
RBP: 00007fdc4cbf175e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fdc4cd35f80 R15: 00007ffe2f870f78
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/15 20:22 upstream f868cd251776 cfe3a04a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ntfs_set_size
2024/10/06 13:32 upstream 8f602276d390 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs possible deadlock in ntfs_set_size
* Struck through repros no longer work on HEAD.