syzbot


possible deadlock in hfsplus_get_block

Status: upstream: reported C repro on 2025/06/17 11:25
Bug presence: origin:upstream
Labels: missing-backport
[Documentation on labels]
Reported-by: syzbot+5620460156f848837a86@syzkaller.appspotmail.com
First crash: 362d, last: 7d08h
Fix bisection: failed (error log, bisect log)
  
Bug presence (3)
Date Name Commit Repro Result
2026/05/20 linux-6.6.y (ToT) eac8889a3a1c C [report] possible deadlock in hfsplus_get_block
2025/06/26 upstream (ToT) e34a79b96ab9 C [report] possible deadlock in hfsplus_get_block
2026/05/19 upstream (ToT) 27fa82620cba C Didn't crash
Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 possible deadlock in hfsplus_get_block missing-backport origin:upstream 4 C 1351 14d 1188d 0/3 upstream: reported C repro on 2023/03/14 12:03
linux-4.19 possible deadlock in hfsplus_get_block hfsplus 4 C 248 1195d 1297d 0/1 upstream: reported C repro on 2022/11/26 01:19
linux-4.14 possible deadlock in hfsplus_get_block hfsplus 4 C 131 1201d 1293d 0/1 upstream: reported C repro on 2022/11/30 01:33
linux-6.1 possible deadlock in hfsplus_get_block origin:lts-only 4 C 1322 1d21h 1189d 0/3 upstream: reported C repro on 2023/03/13 14:59
upstream possible deadlock in hfsplus_get_block hfs prio:high 4 C error 15630 1d18h 1297d 0/29 upstream: reported C repro on 2022/11/25 09:45
Fix bisection attempts (2)
Created Duration User Patch Repo Result
2026/02/15 08:59 4m bisect fix linux-6.6.y error job log
2025/11/25 15:12 2h36m bisect fix linux-6.6.y OK (0) job log log

Sample crash report:
syz.0.17[5927]: memfd_create() called without MFD_EXEC or MFD_NOEXEC_SEAL set
loop0: detected capacity change from 0 to 1024
============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.0.17/5927 is trying to acquire lock:
ffff88802b769548 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_get_block+0x3a5/0x15a0 fs/hfsplus/extents.c:260

but task is already holding lock:
ffff88802b76a988 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x2bb/0xb60 fs/hfsplus/extents.c:574

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&HFSPLUS_I(inode)->extents_lock);
  lock(&HFSPLUS_I(inode)->extents_lock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

4 locks held by syz.0.17/5927:
 #0: ffff888079306418 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:412
 #1: ffff88802b76ab90 (&sb->s_type->i_mutex_key#20){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
 #1: ffff88802b76ab90 (&sb->s_type->i_mutex_key#20){+.+.}-{3:3}, at: do_truncate+0x19c/0x240 fs/open.c:64
 #2: ffff88802b76a988 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_truncate+0x2bb/0xb60 fs/hfsplus/extents.c:574
 #3: ffff88802cbdb0f8 (&sbi->alloc_mutex){+.+.}-{3:3}, at: hfsplus_block_free+0xc3/0x4b0 fs/hfsplus/bitmap.c:182

stack backtrace:
CPU: 0 PID: 5927 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 check_deadlock kernel/locking/lockdep.c:3062 [inline]
 validate_chain kernel/locking/lockdep.c:3856 [inline]
 __lock_acquire+0x5dbc/0x7d40 kernel/locking/lockdep.c:5137
 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x136/0xcc0 kernel/locking/mutex.c:747
 hfsplus_get_block+0x3a5/0x15a0 fs/hfsplus/extents.c:260
 block_read_full_folio+0x44b/0xf60 fs/buffer.c:2406
 filemap_read_folio+0x172/0x760 mm/filemap.c:2420
 do_read_cache_folio+0x468/0x7d0 mm/filemap.c:3809
 do_read_cache_page+0x32/0x250 mm/filemap.c:3875
 read_mapping_page include/linux/pagemap.h:892 [inline]
 hfsplus_block_free+0x12c/0x4b0 fs/hfsplus/bitmap.c:185
 hfsplus_free_extents+0x10d/0xa50 fs/hfsplus/extents.c:360
 hfsplus_file_truncate+0x769/0xb60 fs/hfsplus/extents.c:589
 hfsplus_setattr+0x1c3/0x280 fs/hfsplus/inode.c:289
 notify_change+0xb0d/0xe10 fs/attr.c:499
 do_truncate+0x1b0/0x240 fs/open.c:66
 handle_truncate fs/namei.c:3299 [inline]
 do_open fs/namei.c:3644 [inline]
 path_openat+0x2a32/0x3230 fs/namei.c:3797
 do_filp_open+0x1f5/0x430 fs/namei.c:3824
 do_sys_openat2+0x134/0x1d0 fs/open.c:1421
 do_sys_open fs/open.c:1436 [inline]
 __do_sys_creat fs/open.c:1514 [inline]
 __se_sys_creat fs/open.c:1508 [inline]
 __x64_sys_creat+0x90/0xb0 fs/open.c:1508
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f5b1599ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd00ebc1e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007f5b15c15fa0 RCX: 00007f5b1599ce59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000000
RBP: 00007f5b15a32d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5b15c15fac R14: 00007f5b15c15fa0 R15: 00007f5b15c15fa0
 </TASK>
hfsplus: unable to mark blocks free: error -5
hfsplus: can't free extent

Crashes (69):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/07 17:57 linux-6.6.y 924b4a879cbb cc095639 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/27 13:59 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/09/18 01:37 linux-6.6.y 60a9e718726f e2beed91 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/09/17 23:03 linux-6.6.y 60a9e718726f e2beed91 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/06/26 03:57 linux-6.6.y 6282921b6825 26d77996 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2026/05/03 06:54 linux-6.6.y 258cf62a6dfd a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2026/04/06 02:14 linux-6.6.y c09fbcd31ae6 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2026/04/04 23:43 linux-6.6.y c09fbcd31ae6 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2026/01/16 08:51 linux-6.6.y c596736dadab d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2026/01/15 15:39 linux-6.6.y c596736dadab d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2026/01/06 07:11 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2026/01/05 00:53 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2026/01/02 17:41 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/31 01:11 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/30 15:40 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/30 14:09 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/30 00:43 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/29 15:15 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/29 06:58 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/29 00:38 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/28 04:14 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/28 02:51 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/27 12:16 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/26 14:48 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/26 03:48 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/26 03:47 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/25 06:35 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/24 05:08 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/24 02:19 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/23 18:06 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/22 23:59 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/21 17:45 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/15 04:01 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/13 15:45 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/12 12:23 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/12 00:32 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/09 18:27 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/06 15:39 linux-6.6.y 4791134e4aeb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/06 15:38 linux-6.6.y 4791134e4aeb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/06 02:05 linux-6.6.y 4791134e4aeb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/06 02:02 linux-6.6.y 4791134e4aeb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/05 15:19 linux-6.6.y 4791134e4aeb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/05 14:04 linux-6.6.y 4791134e4aeb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/05 13:59 linux-6.6.y 4791134e4aeb d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/12/01 04:58 linux-6.6.y 1e89a1be4fe9 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/10/25 22:06 linux-6.6.y 4a243110dc88 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/10/25 22:04 linux-6.6.y 4a243110dc88 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/10/23 10:31 linux-6.6.y f231f248323d c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/10/22 01:30 linux-6.6.y f231f248323d 9832ed61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/10/22 01:30 linux-6.6.y f231f248323d 9832ed61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/10/12 10:19 linux-6.6.y e617101e5626 ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/09/15 03:46 linux-6.6.y 60a9e718726f e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/09/15 03:43 linux-6.6.y 60a9e718726f e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/08/18 11:37 linux-6.6.y bb9c90ab9c5a 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/08/18 11:32 linux-6.6.y bb9c90ab9c5a 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/07/27 12:15 linux-6.6.y dbcb8d8e4163 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/07/24 05:18 linux-6.6.y d96eb99e2f0e 0c1d6ded .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/07/24 05:18 linux-6.6.y d96eb99e2f0e 0c1d6ded .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/07/18 13:04 linux-6.6.y d96eb99e2f0e 88248e14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/07/18 13:04 linux-6.6.y d96eb99e2f0e 88248e14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/06/17 11:24 linux-6.6.y c2603c511feb cfebc887 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
2025/06/17 11:24 linux-6.6.y c2603c511feb cfebc887 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in hfsplus_get_block
* Struck through repros no longer work on HEAD.