possible deadlock in hfsplus_file_extend (2)

Status: auto-obsoleted due to no activity on 2025/04/22 11:08
Reported-by: syzbot+f250f2829bf8deda7ffa@syzkaller.appspotmail.com
First crash: 566d, last: 566d
▶ ▼ Similar bugs (12)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 possible deadlock in hfsplus_file_extend (3) 4 4 284d 286d 0/3 auto-obsoleted due to no activity on 2026/01/30 04:03
linux-6.1 possible deadlock in hfsplus_file_extend origin:upstream missing-backport 4 syz, C done 2760 728d 1237d 3/3 fixed on 2024/09/08 06:54
linux-5.15 possible deadlock in hfsplus_file_extend (3) 4 10 262d 284d 0/3 auto-obsoleted due to no activity on 2026/01/21 08:03
upstream possible deadlock in hfsplus_file_extend (2) prio:normal hfs 4 syz, C inconclusive error 912 39d 628d 0/29 upstream: reported C repro on 2024/11/11 11:50
linux-5.15 possible deadlock in hfsplus_file_extend (2) 4 7 607d 657d 0/3 auto-obsoleted due to no activity on 2025/03/13 03:31
linux-4.14 possible deadlock in hfsplus_file_extend hfsplus 4 syz, C 3 1245d 1311d 0/1 upstream: reported C repro on 2022/12/29 06:07
linux-6.6 possible deadlock in hfsplus_file_extend origin:upstream 4 syz, C error 4 172d 289d 0/2 upstream: reported C repro on 2025/10/16 15:40
linux-5.15 possible deadlock in hfsplus_file_extend missing-backport origin:lts-only 4 syz, C done 3439 713d 1239d 3/3 fixed on 2024/09/23 09:27
linux-6.1 possible deadlock in hfsplus_file_extend (4) 4 syz, C error 14 6d19h 171d 0/3 upstream: reported C repro on 2026/02/11 15:48
linux-4.19 possible deadlock in hfsplus_file_extend hfsplus 4 syz, C 258 1244d 1344d 0/1 upstream: reported C repro on 2022/11/26 10:00
linux-5.15 possible deadlock in hfsplus_file_extend (4) 4 3 172d 172d 0/3 auto-obsoleted due to no activity on 2026/05/22 01:53
upstream possible deadlock in hfsplus_file_extend hfs 4 syz, C error done 31659 656d 1344d 28/29 fixed on 2024/10/21 12:45

Sample crash report:
loop2: detected capacity change from 0 to 1024
======================================================
WARNING: possible circular locking dependency detected
6.1.124-syzkaller #0 Not tainted
------------------------------------------------------
syz.2.10521/7921 is trying to acquire lock:
ffff888058196648 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x1d2/0x1b10 fs/hfsplus/extents.c:458

but task is already holding lock:
ffff8880550a80b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x146/0x1c0 fs/hfsplus/bfind.c:28

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&tree->tree_lock/1){+.+.}-{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_find_init+0x146/0x1c0 fs/hfsplus/bfind.c:28
       hfsplus_ext_write_extent_locked fs/hfsplus/extents.c:136 [inline]
       hfsplus_ext_write_extent+0x13e/0x1f0 fs/hfsplus/extents.c:150
       hfsplus_write_inode+0x1e/0x5c0 fs/hfsplus/super.c:154
       write_inode fs/fs-writeback.c:1460 [inline]
       __writeback_single_inode+0x67d/0x11e0 fs/fs-writeback.c:1677
       writeback_single_inode+0x22c/0x960 fs/fs-writeback.c:1733
       sync_inode_metadata+0xc8/0x130 fs/fs-writeback.c:2789
       hfsplus_file_fsync+0xf4/0x4c0 fs/hfsplus/inode.c:321
       generic_write_sync include/linux/fs.h:2962 [inline]
       generic_file_write_iter+0x29d/0x310 mm/filemap.c:4009
       do_iter_write+0x6e6/0xc40 fs/read_write.c:861
       vfs_writev fs/read_write.c:934 [inline]
       do_pwritev+0x216/0x360 fs/read_write.c:1031
       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 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{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_file_extend+0x1d2/0x1b10 fs/hfsplus/extents.c:458
       hfsplus_bmap_reserve+0x101/0x4e0 fs/hfsplus/btree.c:358
       __hfsplus_ext_write_extent+0x2a4/0x5b0 fs/hfsplus/extents.c:104
       __hfsplus_ext_cache_extent+0x84/0xe00 fs/hfsplus/extents.c:186
       hfsplus_ext_read_extent fs/hfsplus/extents.c:218 [inline]
       hfsplus_file_extend+0x435/0x1b10 fs/hfsplus/extents.c:462
       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
       generic_perform_write+0x2fc/0x5e0 mm/filemap.c:3845
       __generic_file_write_iter+0x176/0x400 mm/filemap.c:3973
       generic_file_write_iter+0xab/0x310 mm/filemap.c:4005
       call_write_iter include/linux/fs.h:2265 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x857/0xbc0 fs/read_write.c:584
       ksys_write+0x19c/0x2c0 fs/read_write.c:637
       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(&tree->tree_lock/1);
                               lock(&HFSPLUS_I(inode)->extents_lock);
                               lock(&tree->tree_lock/1);
  lock(&HFSPLUS_I(inode)->extents_lock);

 *** DEADLOCK ***

5 locks held by syz.2.10521/7921:
 #0: ffff88807bd5e368 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ba/0x360 fs/file.c:1031
 #1: ffff8880550ae460 (sb_writers#22){.+.+}-{0:0}, at: vfs_write+0x269/0xbc0 fs/read_write.c:580
 #2: ffff8880581924c0 (&sb->s_type->i_mutex_key#28){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #2: ffff8880581924c0 (&sb->s_type->i_mutex_key#28){+.+.}-{3:3}, at: generic_file_write_iter+0x7f/0x310 mm/filemap.c:4002
 #3: ffff8880581922c8 (&hip->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x1d2/0x1b10 fs/hfsplus/extents.c:458
 #4: ffff8880550a80b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x146/0x1c0 fs/hfsplus/bfind.c:28

stack backtrace:
CPU: 0 PID: 7921 Comm: syz.2.10521 Not tainted 6.1.124-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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_file_extend+0x1d2/0x1b10 fs/hfsplus/extents.c:458
 hfsplus_bmap_reserve+0x101/0x4e0 fs/hfsplus/btree.c:358
 __hfsplus_ext_write_extent+0x2a4/0x5b0 fs/hfsplus/extents.c:104
 __hfsplus_ext_cache_extent+0x84/0xe00 fs/hfsplus/extents.c:186
 hfsplus_ext_read_extent fs/hfsplus/extents.c:218 [inline]
 hfsplus_file_extend+0x435/0x1b10 fs/hfsplus/extents.c:462
 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
 generic_perform_write+0x2fc/0x5e0 mm/filemap.c:3845
 __generic_file_write_iter+0x176/0x400 mm/filemap.c:3973
 generic_file_write_iter+0xab/0x310 mm/filemap.c:4005
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x857/0xbc0 fs/read_write.c:584
 ksys_write+0x19c/0x2c0 fs/read_write.c:637
 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: 0033:0x7f03f3b85d29
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f03f4909038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f03f3d75fa0 RCX: 00007f03f3b85d29
RDX: 000000000000fd14 RSI: 0000000020000140 RDI: 0000000000000004
RBP: 00007f03f3c01b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f03f3d75fa0 R15: 00007ffd6ecc8ab8
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/01/12 11:07 linux-6.1.y c63962be84ef 6dbc6a9b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfsplus_file_extend
2025/01/12 11:07 linux-6.1.y c63962be84ef 6dbc6a9b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfsplus_file_extend
* Struck through repros no longer work on HEAD.