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Date:   Tue, 12 Dec 2023 05:42:30 -0800
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Subject: [syzbot] [hfs?] possible deadlock in hfs_extend_file (2)
From:   syzbot <syzbot+41a88b825a315aac2254@syzkaller.appspotmail.com>
To:     linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        syzkaller-bugs@googlegroups.com
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Hello,

syzbot found the following issue on:

HEAD commit:    bee0e7762ad2 Merge tag 'for-linus-iommufd' of git://git.ke..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1500ff54e80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b45dfd882e46ec91
dashboard link: https://syzkaller.appspot.com/bug?extid=41a88b825a315aac2254
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/af357ba4767f/disk-bee0e776.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ae4d50206171/vmlinux-bee0e776.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e12203376a9f/bzImage-bee0e776.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+41a88b825a315aac2254@syzkaller.appspotmail.com

loop5: detected capacity change from 0 to 64
======================================================
WARNING: possible circular locking dependency detected
6.7.0-rc4-syzkaller-00009-gbee0e7762ad2 #0 Not tainted
------------------------------------------------------
syz-executor.5/10381 is trying to acquire lock:
ffff888080716f78 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xff/0x1440 fs/hfs/extent.c:397

but task is already holding lock:
ffff8880396060b0 (&tree->tree_lock#2/1){+.+.}-{3:3}, at: hfs_find_init+0x16e/0x1f0

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&tree->tree_lock#2/1){+.+.}-{3:3}:
       lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x136/0xd60 kernel/locking/mutex.c:747
       hfs_find_init+0x16e/0x1f0
       hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
       hfs_extend_file+0x31b/0x1440 fs/hfs/extent.c:401
       hfs_bmap_reserve+0xd9/0x3f0 fs/hfs/btree.c:234
       hfs_cat_create+0x1e0/0x970 fs/hfs/catalog.c:104
       hfs_create+0x66/0xd0 fs/hfs/dir.c:202
       lookup_open fs/namei.c:3477 [inline]
       open_last_lookups fs/namei.c:3546 [inline]
       path_openat+0x13fa/0x3290 fs/namei.c:3776
       do_filp_open+0x234/0x490 fs/namei.c:3809
       do_sys_openat2+0x13e/0x1d0 fs/open.c:1440
       do_sys_open fs/open.c:1455 [inline]
       __do_sys_openat fs/open.c:1471 [inline]
       __se_sys_openat fs/open.c:1466 [inline]
       __x64_sys_openat+0x247/0x290 fs/open.c:1466
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x45/0x110 arch/x86/entry/common.c:82
       entry_SYSCALL_64_after_hwframe+0x63/0x6b

-> #0 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain+0x1909/0x5ab0 kernel/locking/lockdep.c:3869
       __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137
       lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x136/0xd60 kernel/locking/mutex.c:747
       hfs_extend_file+0xff/0x1440 fs/hfs/extent.c:397
       hfs_bmap_reserve+0xd9/0x3f0 fs/hfs/btree.c:234
       __hfs_ext_write_extent+0x22e/0x4f0 fs/hfs/extent.c:121
       __hfs_ext_cache_extent+0x6a/0x990 fs/hfs/extent.c:174
       hfs_ext_read_extent fs/hfs/extent.c:202 [inline]
       hfs_extend_file+0x344/0x1440 fs/hfs/extent.c:401
       hfs_get_block+0x3e4/0xb60 fs/hfs/extent.c:353
       __block_write_begin_int+0x54d/0x1ad0 fs/buffer.c:2119
       __block_write_begin fs/buffer.c:2168 [inline]
       block_write_begin+0x9b/0x1e0 fs/buffer.c:2227
       cont_write_begin+0x643/0x880 fs/buffer.c:2582
       hfs_write_begin+0x8a/0xd0 fs/hfs/inode.c:58
       generic_perform_write+0x31b/0x630 mm/filemap.c:3918
       generic_file_write_iter+0xaf/0x310 mm/filemap.c:4039
       call_write_iter include/linux/fs.h:2020 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x792/0xb20 fs/read_write.c:584
       ksys_write+0x1a0/0x2c0 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x45/0x110 arch/x86/entry/common.c:82
       entry_SYSCALL_64_after_hwframe+0x63/0x6b

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&tree->tree_lock#2/1);
                               lock(&HFS_I(tree->inode)->extents_lock);
                               lock(&tree->tree_lock#2/1);
  lock(&HFS_I(tree->inode)->extents_lock);

 *** DEADLOCK ***

5 locks held by syz-executor.5/10381:
 #0: ffff888018664fc8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2b0/0x340 fs/file.c:1177
 #1: ffff88807234c418 (sb_writers#20){.+.+}-{0:0}, at: vfs_write+0x223/0xb20 fs/read_write.c:580
 #2: ffff888080715da8 (&sb->s_type->i_mutex_key#28){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:802 [inline]
 #2: ffff888080715da8 (&sb->s_type->i_mutex_key#28){+.+.}-{3:3}, at: generic_file_write_iter+0x83/0x310 mm/filemap.c:4036
 #3: ffff888080715bf8 (&HFS_I(inode)->extents_lock#2){+.+.}-{3:3}, at: hfs_extend_file+0xff/0x1440 fs/hfs/extent.c:397
 #4: ffff8880396060b0 (&tree->tree_lock#2/1){+.+.}-{3:3}, at: hfs_find_init+0x16e/0x1f0

stack backtrace:
CPU: 1 PID: 10381 Comm: syz-executor.5 Not tainted 6.7.0-rc4-syzkaller-00009-gbee0e7762ad2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 check_noncircular+0x366/0x490 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain+0x1909/0x5ab0 kernel/locking/lockdep.c:3869
 __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137
 lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x136/0xd60 kernel/locking/mutex.c:747
 hfs_extend_file+0xff/0x1440 fs/hfs/extent.c:397
 hfs_bmap_reserve+0xd9/0x3f0 fs/hfs/btree.c:234
 __hfs_ext_write_extent+0x22e/0x4f0 fs/hfs/extent.c:121
 __hfs_ext_cache_extent+0x6a/0x990 fs/hfs/extent.c:174
 hfs_ext_read_extent fs/hfs/extent.c:202 [inline]
 hfs_extend_file+0x344/0x1440 fs/hfs/extent.c:401
 hfs_get_block+0x3e4/0xb60 fs/hfs/extent.c:353
 __block_write_begin_int+0x54d/0x1ad0 fs/buffer.c:2119
 __block_write_begin fs/buffer.c:2168 [inline]
 block_write_begin+0x9b/0x1e0 fs/buffer.c:2227
 cont_write_begin+0x643/0x880 fs/buffer.c:2582
 hfs_write_begin+0x8a/0xd0 fs/hfs/inode.c:58
 generic_perform_write+0x31b/0x630 mm/filemap.c:3918
 generic_file_write_iter+0xaf/0x310 mm/filemap.c:4039
 call_write_iter include/linux/fs.h:2020 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x792/0xb20 fs/read_write.c:584
 ksys_write+0x1a0/0x2c0 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x45/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f8f6167cae9
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:00007f8f6230d0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f8f6179bf80 RCX: 00007f8f6167cae9
RDX: 00000000000ffe00 RSI: 0000000020004200 RDI: 0000000000000004
RBP: 00007f8f616c847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f8f6179bf80 R15: 00007ffcca30fd58
 </TASK>


---
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