[syzbot] possible deadlock in hfsplus_block_free

From: syzbot
Date: Tue Nov 29 2022 - 03:34:15 EST

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Hello,

syzbot found the following issue on:

HEAD commit: ca57f02295f1 afs: Fix fileserver probe RTT handling
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16afa373880000
kernel config: https://syzkaller.appspot.com/x/.config?x=2325e409a9a893e1
dashboard link: https://syzkaller.appspot.com/bug?extid=8fae81a1f77bf28ef3b5
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/af66f1d3a389/disk-ca57f022.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c0c7ec393108/vmlinux-ca57f022.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ea8871940eaa/bzImage-ca57f022.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8fae81a1f77bf28ef3b5@xxxxxxxxxxxxxxxxxxxxxxxxx

======================================================
WARNING: possible circular locking dependency detected
6.1.0-rc7-syzkaller-00012-gca57f02295f1 #0 Not tainted
------------------------------------------------------
syz-executor.3/5709 is trying to acquire lock:
ffff88807cb5b8f8 (&sbi->alloc_mutex){+.+.}-{3:3}, at: hfsplus_block_free+0xb6/0x4e0 fs/hfsplus/bitmap.c:182

but task is already holding lock:
ffff8880189f5f88 (&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_get_block+0x3a3/0x1560 fs/hfsplus/extents.c:260
block_read_full_folio+0x3b3/0xfa0 fs/buffer.c:2271
filemap_read_folio+0x187/0x7d0 mm/filemap.c:2407
do_read_cache_folio+0x2d3/0x790 mm/filemap.c:3534
do_read_cache_page mm/filemap.c:3576 [inline]
read_cache_page+0x56/0x270 mm/filemap.c:3585
read_mapping_page include/linux/pagemap.h:756 [inline]
hfsplus_block_allocate+0xf9/0x900 fs/hfsplus/bitmap.c:37
hfsplus_file_extend+0x9d4/0x19d0 fs/hfsplus/extents.c:468
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
generic_perform_write+0x2e4/0x5e0 mm/filemap.c:3753
__generic_file_write_iter+0x176/0x400 mm/filemap.c:3881
generic_file_write_iter+0xab/0x310 mm/filemap.c:3913
call_write_iter include/linux/fs.h:2199 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x7dc/0xc50 fs/read_write.c:584
ksys_write+0x177/0x2a0 fs/read_write.c:637
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 (&sbi->alloc_mutex){+.+.}-{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_block_free+0xb6/0x4e0 fs/hfsplus/bitmap.c:182
hfsplus_free_extents+0x17f/0xad0 fs/hfsplus/extents.c:363
hfsplus_file_truncate+0x827/0xbb0 fs/hfsplus/extents.c:591
hfsplus_delete_inode+0x16d/0x210
hfsplus_unlink+0x4e2/0x7d0 fs/hfsplus/dir.c:405
vfs_unlink+0x357/0x5f0 fs/namei.c:4252
do_unlinkat+0x484/0x940 fs/namei.c:4320
__do_sys_unlinkat fs/namei.c:4363 [inline]
__se_sys_unlinkat fs/namei.c:4356 [inline]
__x64_sys_unlinkat+0xca/0xf0 fs/namei.c:4356
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(&sbi->alloc_mutex);
lock(&HFSPLUS_I(inode)->extents_lock);
lock(&sbi->alloc_mutex);

*** DEADLOCK ***

5 locks held by syz-executor.3/5709:
#0: ffff88805777e460 (sb_writers#23){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:393
#1: ffff8880189f5ac0 (&type->i_mutex_dir_key#18/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:791 [inline]
#1: ffff8880189f5ac0 (&type->i_mutex_dir_key#18/1){+.+.}-{3:3}, at: do_unlinkat+0x23d/0x940 fs/namei.c:4303
#2: ffff8880189f6180 (&sb->s_type->i_mutex_key#29){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:756 [inline]
#2: ffff8880189f6180 (&sb->s_type->i_mutex_key#29){+.+.}-{3:3}, at: vfs_unlink+0xe0/0x5f0 fs/namei.c:4241
#3: ffff88807cb5b998 (&sbi->vh_mutex){+.+.}-{3:3}, at: hfsplus_unlink+0x135/0x7d0 fs/hfsplus/dir.c:370
#4: ffff8880189f5f88 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x280/0xbb0 fs/hfsplus/extents.c:576

stack backtrace:
CPU: 0 PID: 5709 Comm: syz-executor.3 Not tainted 6.1.0-rc7-syzkaller-00012-gca57f02295f1 #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+0x1b1/0x28e 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_block_free+0xb6/0x4e0 fs/hfsplus/bitmap.c:182
hfsplus_free_extents+0x17f/0xad0 fs/hfsplus/extents.c:363
hfsplus_file_truncate+0x827/0xbb0 fs/hfsplus/extents.c:591
hfsplus_delete_inode+0x16d/0x210
hfsplus_unlink+0x4e2/0x7d0 fs/hfsplus/dir.c:405
vfs_unlink+0x357/0x5f0 fs/namei.c:4252
do_unlinkat+0x484/0x940 fs/namei.c:4320
__do_sys_unlinkat fs/namei.c:4363 [inline]
__se_sys_unlinkat fs/namei.c:4356 [inline]
__x64_sys_unlinkat+0xca/0xf0 fs/namei.c:4356
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: 0033:0x7feeca28c0d9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 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:00007feecafb5168 EFLAGS: 00000246 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 00007feeca3abf80 RCX: 00007feeca28c0d9
RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000005
RBP: 00007feeca2e7ae9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffeb5f149df R14: 00007feecafb5300 R15: 0000000000022000
</TASK>

---
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Next message: Christoph Hellwig: "Re: [PATCH 2/4] elevator: replace continue with else-if in elv_iosched_show"
Previous message: syzbot: "[syzbot] INFO: task hung in gfs2_gl_hash_clear (3)"
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