[syzbot] [hfsplus?] possible deadlock in hfsplus_find_init

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: b6bb9676f216 Merge tag 'm68knommu-for-v6.2' of git://git.k..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=167bb2c8480000
kernel config: https://syzkaller.appspot.com/x/.config?x=d3fb546de56fbf8d
dashboard link: https://syzkaller.appspot.com/bug?extid=f8ce6c197125ab9d72ce
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=105f5464480000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13994073880000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/2f703f794500/disk-b6bb9676.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/0cca7cdd545b/vmlinux-b6bb9676.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0ce2560b7652/bzImage-b6bb9676.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/8ddb7c2fc877/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f8ce6c...@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
6.1.0-syzkaller-13872-gb6bb9676f216 #0 Not tainted
------------------------------------------------------
syz-executor156/5069 is trying to acquire lock:
ffff88802b6920b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x143/0x1b0

but task is already holding lock:
ffff88802953b048 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x280/0xbb0 fs/hfsplus/extents.c:576

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}:
lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
__mutex_lock_common+0x1bd/0x26e0 kernel/locking/mutex.c:603
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
hfsplus_file_extend+0x1af/0x19d0 fs/hfsplus/extents.c:457
hfsplus_bmap_reserve+0x123/0x500 fs/hfsplus/btree.c:358
__hfsplus_ext_write_extent+0x28e/0x590 fs/hfsplus/extents.c:104
__hfsplus_ext_cache_extent+0x8d/0x810 fs/hfsplus/extents.c:186
hfsplus_ext_read_extent fs/hfsplus/extents.c:218 [inline]
hfsplus_file_extend+0x3cc/0x19d0 fs/hfsplus/extents.c:461
hfsplus_get_block+0x415/0x1560 fs/hfsplus/extents.c:245
__block_write_begin_int+0x54c/0x1a80 fs/buffer.c:1991
__block_write_begin fs/buffer.c:2041 [inline]
block_write_begin+0x93/0x1e0 fs/buffer.c:2102
cont_write_begin+0x606/0x860 fs/buffer.c:2456
hfsplus_write_begin+0x86/0xd0 fs/hfsplus/inode.c:52
cont_expand_zero fs/buffer.c:2383 [inline]
cont_write_begin+0x2cf/0x860 fs/buffer.c:2446
hfsplus_write_begin+0x86/0xd0 fs/hfsplus/inode.c:52
generic_cont_expand_simple+0x151/0x250 fs/buffer.c:2347
hfsplus_setattr+0x168/0x280 fs/hfsplus/inode.c:263
notify_change+0xe50/0x1100 fs/attr.c:482
do_truncate+0x200/0x2f0 fs/open.c:65
do_sys_ftruncate+0x2b0/0x350 fs/open.c:193
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #0 (&tree->tree_lock/1){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3097 [inline]
check_prevs_add kernel/locking/lockdep.c:3216 [inline]
validate_chain+0x1898/0x6ae0 kernel/locking/lockdep.c:3831
__lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5055
lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
__mutex_lock_common+0x1bd/0x26e0 kernel/locking/mutex.c:603
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
hfsplus_find_init+0x143/0x1b0
hfsplus_file_truncate+0x3d1/0xbb0 fs/hfsplus/extents.c:582
hfsplus_setattr+0x1b8/0x280 fs/hfsplus/inode.c:269
notify_change+0xe50/0x1100 fs/attr.c:482
do_truncate+0x200/0x2f0 fs/open.c:65
do_sys_ftruncate+0x2b0/0x350 fs/open.c:193
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

other info that might help us debug this:

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&HFSPLUS_I(inode)->extents_lock);
lock(&tree->tree_lock/1);
lock(&HFSPLUS_I(inode)->extents_lock);
lock(&tree->tree_lock/1);

*** DEADLOCK ***

3 locks held by syz-executor156/5069:
#0: ffff88802b690460 (sb_writers#9){.+.+}-{0:0}, at: do_sys_ftruncate+0x243/0x350 fs/open.c:190
#1: ffff88802953b240 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:756 [inline]
#1: ffff88802953b240 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}, at: do_truncate+0x1ec/0x2f0 fs/open.c:63
#2: ffff88802953b048 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x280/0xbb0 fs/hfsplus/extents.c:576

stack backtrace:
CPU: 0 PID: 5069 Comm: syz-executor156 Not tainted 6.1.0-syzkaller-13872-gb6bb9676f216 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1b1/0x290 lib/dump_stack.c:106
check_noncircular+0x2cc/0x390 kernel/locking/lockdep.c:2177
check_prev_add kernel/locking/lockdep.c:3097 [inline]
check_prevs_add kernel/locking/lockdep.c:3216 [inline]
validate_chain+0x1898/0x6ae0 kernel/locking/lockdep.c:3831
__lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5055
lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
__mutex_lock_common+0x1bd/0x26e0 kernel/locking/mutex.c:603
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
hfsplus_find_init+0x143/0x1b0
hfsplus_file_truncate+0x3d1/0xbb0 fs/hfsplus/extents.c:582
hfsplus_setattr+0x1b8/0x280 fs/hfsplus/inode.c:269
notify_change+0xe50/0x1100 fs/attr.c:482
do_truncate+0x200/0x2f0 fs/open.c:65
do_sys_ftruncate+0x2b0/0x350 fs/open.c:193
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f0cadd0a239
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 14 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffccf2763a8 EFLAGS: 00000246 ORIG_RAX: 000000000000004d
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0cadd0a239
RDX: 00007f0cadd0a239 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 0000000000000000 R08: 00007f0cadd78ec0 R09: 00007f0cadd78ec0
R10: 00007f0cadd78ec0 R11: 0000000000000246 R12: 00007ffccf2763d0
R13: 0000000000000000 R14: 431bde82d7b634db R15: 0000000000000000
</TASK>


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