syzbot


possible deadlock in hfsplus_block_free (2)

Status: upstream: reported on 2024/06/07 11:36
Reported-by: syzbot+ffef020b8300527d0d56@syzkaller.appspotmail.com
First crash: 44d, last: 44d
Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 possible deadlock in hfsplus_block_free hfsplus 10 512d 597d 0/1 upstream: reported on 2022/12/01 19:36
linux-4.19 possible deadlock in hfsplus_block_free hfsplus 20 503d 594d 0/1 upstream: reported on 2022/12/04 19:32
upstream possible deadlock in hfsplus_block_free hfs C inconclusive 241 4d06h 600d 0/27 upstream: reported C repro on 2022/11/29 08:32
linux-5.15 possible deadlock in hfsplus_block_free 20 271d 475d 0/3 auto-obsoleted due to no activity on 2024/01/31 18:41
linux-5.15 possible deadlock in hfsplus_block_free (2) 1 44d 44d 0/3 upstream: reported on 2024/06/07 11:28
linux-6.1 possible deadlock in hfsplus_block_free 27 197d 461d 0/3 auto-obsoleted due to no activity on 2024/04/14 19:02

Sample crash report:
loop3: detected capacity change from 0 to 1024
======================================================
WARNING: possible circular locking dependency detected
6.1.92-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.3/11690 is trying to acquire lock:
ffff88801f0b68f8 (&sbi->alloc_mutex){+.+.}-{3:3}, at: hfsplus_block_free+0xb7/0x4d0 fs/hfsplus/bitmap.c:182

but task is already holding lock:
ffff88807dc8bdc8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x2d6/0xb40 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+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747
       hfsplus_get_block+0x37f/0x14e0 fs/hfsplus/extents.c:260
       block_read_full_folio+0x403/0xf60 fs/buffer.c:2271
       filemap_read_folio+0x199/0x780 mm/filemap.c:2461
       do_read_cache_folio+0x2ee/0x810 mm/filemap.c:3598
       do_read_cache_page+0x32/0x220 mm/filemap.c:3640
       read_mapping_page include/linux/pagemap.h:791 [inline]
       hfsplus_block_allocate+0xea/0x8b0 fs/hfsplus/bitmap.c:37
       hfsplus_file_extend+0xa4c/0x1b10 fs/hfsplus/extents.c:468
       hfsplus_get_block+0x402/0x14e0 fs/hfsplus/extents.c:245
       __block_write_begin_int+0x544/0x1a30 fs/buffer.c:1991
       __block_write_begin fs/buffer.c:2041 [inline]
       block_write_begin+0x98/0x1f0 fs/buffer.c:2102
       cont_write_begin+0x63f/0x880 fs/buffer.c:2456
       hfsplus_write_begin+0x86/0xd0 fs/hfsplus/inode.c:52
       page_symlink+0x2c1/0x4e0 fs/namei.c:5220
       hfsplus_symlink+0xc6/0x260 fs/hfsplus/dir.c:449
       vfs_symlink+0x247/0x3d0 fs/namei.c:4473
       do_symlinkat+0x21e/0x390 fs/namei.c:4502
       __do_sys_symlinkat fs/namei.c:4519 [inline]
       __se_sys_symlinkat fs/namei.c:4516 [inline]
       __x64_sys_symlinkat+0x95/0xa0 fs/namei.c:4516
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&sbi->alloc_mutex){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
       __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747
       hfsplus_block_free+0xb7/0x4d0 fs/hfsplus/bitmap.c:182
       hfsplus_free_extents+0x17a/0xae0 fs/hfsplus/extents.c:363
       hfsplus_file_truncate+0x7cc/0xb40 fs/hfsplus/extents.c:591
       hfsplus_setattr+0x1b9/0x280 fs/hfsplus/inode.c:269
       notify_change+0xce3/0xfc0 fs/attr.c:499
       do_truncate+0x21c/0x300 fs/open.c:65
       vfs_truncate+0x2dd/0x3a0 fs/open.c:111
       do_sys_truncate+0xda/0x190 fs/open.c:134
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

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 ***

3 locks held by syz-executor.3/11690:
 #0: ffff888024d4c460 (sb_writers#24){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:393
 #1: ffff88807dc8bfc0 (&sb->s_type->i_mutex_key#34){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #1: ffff88807dc8bfc0 (&sb->s_type->i_mutex_key#34){+.+.}-{3:3}, at: do_truncate+0x208/0x300 fs/open.c:63
 #2: ffff88807dc8bdc8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x2d6/0xb40 fs/hfsplus/extents.c:576

stack backtrace:
CPU: 1 PID: 11690 Comm: syz-executor.3 Not tainted 6.1.92-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747
 hfsplus_block_free+0xb7/0x4d0 fs/hfsplus/bitmap.c:182
 hfsplus_free_extents+0x17a/0xae0 fs/hfsplus/extents.c:363
 hfsplus_file_truncate+0x7cc/0xb40 fs/hfsplus/extents.c:591
 hfsplus_setattr+0x1b9/0x280 fs/hfsplus/inode.c:269
 notify_change+0xce3/0xfc0 fs/attr.c:499
 do_truncate+0x21c/0x300 fs/open.c:65
 vfs_truncate+0x2dd/0x3a0 fs/open.c:111
 do_sys_truncate+0xda/0x190 fs/open.c:134
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fc2ee67cf69
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:00007fc2ef4c50c8 EFLAGS: 00000246 ORIG_RAX: 000000000000004c
RAX: ffffffffffffffda RBX: 00007fc2ee7b3f80 RCX: 00007fc2ee67cf69
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000000
RBP: 00007fc2ee6da6fe R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fc2ee7b3f80 R15: 00007ffd54950208
 </TASK>

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/07 12:26 linux-6.1.y 88690811da69 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfsplus_block_free
2024/06/07 12:06 linux-6.1.y 88690811da69 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfsplus_block_free
2024/06/07 13:42 linux-6.1.y 88690811da69 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in hfsplus_block_free
2024/06/07 11:35 linux-6.1.y 88690811da69 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in hfsplus_block_free
* Struck through repros no longer work on HEAD.