[syzbot] [ntfs3?] possible deadlock in ntfs_file_mmap

[syzbot] [ntfs3?] possible deadlock in ntfs_file_mmap

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    a957267fa7e9 Add linux-next specific files for 20240611
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1139caa2980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=9a880e96898e79f8
dashboard link: https://syzkaller.appspot.com/bug?extid=c1751b6739d83d70bb75
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/6451759a606b/disk-a957267f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7f635dbe5b8a/vmlinux-a957267f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/33eafd1b8aec/bzImage-a957267f.xz

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

loop0: detected capacity change from 0 to 4096
ntfs3: loop0: Different NTFS sector size (4096) and media sector size (512).
======================================================
WARNING: possible circular locking dependency detected
6.10.0-rc3-next-20240611-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.0/9000 is trying to acquire lock:
ffff88805b15dbb8 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:795 [inline]
ffff88805b15dbb8 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: ntfs_file_mmap+0x5d8/0x860 fs/ntfs3/file.c:302

but task is already holding lock:
ffff88807d087398 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:122 [inline]
ffff88807d087398 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x17c/0x3d0 mm/util.c:571

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:5817
       gup_fast_fallback+0x24c/0x2b40 mm/gup.c:3534
       pin_user_pages_fast+0xcc/0x160 mm/gup.c:3658
       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+0x150f/0x49d0 fs/direct-io.c:1249
       blockdev_direct_IO include/linux/fs.h:3201 [inline]
       ntfs_direct_IO+0x195/0x370 fs/ntfs3/inode.c:803
       generic_file_direct_write+0x130/0x350 mm/filemap.c:3941
       __generic_file_write_iter+0x129/0x230 mm/filemap.c:4097
       ntfs_file_write_iter+0x68f/0x770 fs/ntfs3/file.c:1126
       new_sync_write fs/read_write.c:497 [inline]
       vfs_write+0xa72/0xc90 fs/read_write.c:590
       ksys_write+0x1a0/0x2c0 fs/read_write.c:643
       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#21){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3159 [inline]
       check_prevs_add kernel/locking/lockdep.c:3278 [inline]
       validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3902
       __lock_acquire+0x1359/0x2000 kernel/locking/lockdep.c:5194
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5817
       down_write+0x3a/0x50 kernel/locking/rwsem.c:1579
       inode_lock include/linux/fs.h:795 [inline]
       ntfs_file_mmap+0x5d8/0x860 fs/ntfs3/file.c:302
       call_mmap include/linux/fs.h:2123 [inline]
       mmap_region+0xe8f/0x2090 mm/mmap.c:2927
       do_mmap+0x8ad/0xfa0 mm/mmap.c:1438
       vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:573
       ksys_mmap_pgoff+0x4f1/0x720 mm/mmap.c:1484
       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#21);
                               lock(&mm->mmap_lock);
  lock(&sb->s_type->i_mutex_key#21);

 *** DEADLOCK ***

1 lock held by syz-executor.0/9000:
 #0: ffff88807d087398 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:122 [inline]
 #0: ffff88807d087398 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x17c/0x3d0 mm/util.c:571

stack backtrace:
CPU: 0 PID: 9000 Comm: syz-executor.0 Not tainted 6.10.0-rc3-next-20240611-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:91 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:117
 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2075
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2204
 check_prev_add kernel/locking/lockdep.c:3159 [inline]
 check_prevs_add kernel/locking/lockdep.c:3278 [inline]
 validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3902
 __lock_acquire+0x1359/0x2000 kernel/locking/lockdep.c:5194
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5817
 down_write+0x3a/0x50 kernel/locking/rwsem.c:1579
 inode_lock include/linux/fs.h:795 [inline]
 ntfs_file_mmap+0x5d8/0x860 fs/ntfs3/file.c:302
 call_mmap include/linux/fs.h:2123 [inline]
 mmap_region+0xe8f/0x2090 mm/mmap.c:2927
 do_mmap+0x8ad/0xfa0 mm/mmap.c:1438
 vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:573
 ksys_mmap_pgoff+0x4f1/0x720 mm/mmap.c:1484
 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: 0033:0x7f7e2707cea9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f7e27de60c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f7e271b3f80 RCX: 00007f7e2707cea9
RDX: 00000000007fffff RSI: 0000000000003000 RDI: 0000000020000000
RBP: 00007f7e270ebff4 R08: 0000000000000004 R09: 0000000000000000
R10: 0000000000000012 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f7e271b3f80 R15: 00007ffee8137f98
 </TASK>


---
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#syz undup

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

[syzbot]

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.

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

[syzbot]

syzbot has bisected this issue to:

commit 69505fe98f198ee813898cbcaf6770949636430b
Author: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Date:   Thu May 30 07:54:07 2024 +0000

    fs/ntfs3: Replace inode_trylock with inode_lock

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=17772623980000
start commit:   2f8c4f506285 Merge tag 'auxdisplay-for-v6.11-tag1' of git:..
git tree:       upstream
final oops:     https://syzkaller.appspot.com/x/report.txt?x=14f72623980000
console output: https://syzkaller.appspot.com/x/log.txt?x=10f72623980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5efb917b1462a973
dashboard link: https://syzkaller.appspot.com/bug?extid=c1751b6739d83d70bb75
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=108328d9980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12e875a1980000

Reported-by: syzbot+c1751b6739d83d70bb75@syzkaller.appspotmail.com
Fixes: 69505fe98f19 ("fs/ntfs3: Replace inode_trylock with inode_lock")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

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

[Hillf Danton]

On Sat, 27 Jul 2024 06:44:20 -0700
> 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
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12e875a1980000

#syz test upstream  2f8c4f506285

--- x/fs/ntfs3/file.c
+++ y/fs/ntfs3/file.c
@@ -365,7 +365,10 @@ static int ntfs_file_mmap(struct file *f
 		}
 
 		if (ni->i_valid < to) {
-			inode_lock(inode);
+			if (!inode_trylock(inode)) {
+				err = -EDEADLK;
+				goto out;
+			}
 			err = ntfs_extend_initialized_size(file, ni,
 							   ni->i_valid, to);
 			inode_unlock(inode);
--

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

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+c1751b6739d83d70bb75@syzkaller.appspotmail.com
Tested-by: syzbot+c1751b6739d83d70bb75@syzkaller.appspotmail.com

Tested on:

commit:         2f8c4f50 Merge tag 'auxdisplay-for-v6.11-tag1' of git:..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=14ad359d980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b698a1b2fcd7ef5f
dashboard link: https://syzkaller.appspot.com/bug?extid=c1751b6739d83d70bb75
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=13533503980000

Note: testing is done by a robot and is best-effort only.