syzbot


possible deadlock in hfs_extend_file (2)

Status: upstream: reported C repro on 2024/04/04 03:11
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+02dc5e479349289abab4@syzkaller.appspotmail.com
First crash: 497d, last: 6d02h
Bug presence (1)
Date Name Commit Repro Result
2025/07/21 upstream (ToT) 89be9a83ccf1 C [report] possible deadlock in hfs_extend_file
Similar bugs (9)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 possible deadlock in hfs_extend_file hfs 4 1 961d 961d 0/1 upstream: reported on 2022/12/27 15:22
linux-5.15 possible deadlock in hfs_extend_file (2) 4 1 660d 660d 0/3 auto-obsoleted due to no activity on 2024/01/31 18:25
linux-6.1 possible deadlock in hfs_extend_file 4 7 698d 885d 0/3 auto-obsoleted due to no activity on 2023/12/24 21:20
upstream possible deadlock in hfs_extend_file hfs 4 46 722d 966d 0/29 auto-obsoleted due to no activity on 2023/11/06 09:48
upstream possible deadlock in hfs_extend_file (3) hfs 4 C unreliable 2363 2h29m 483d 0/29 upstream: reported C repro on 2024/04/18 14:41
linux-5.15 possible deadlock in hfs_extend_file (3) 4 155 6d02h 519d 0/3 upstream: reported on 2024/03/13 05:11
linux-6.6 possible deadlock in hfs_extend_file origin:upstream 4 C 20 6d15h 58d 0/2 upstream: reported C repro on 2025/06/17 13:12
upstream possible deadlock in hfs_extend_file (2) hfs 4 C done done 4 590d 611d 0/29 auto-obsoleted due to no activity on 2024/04/11 05:11
linux-5.15 possible deadlock in hfs_extend_file 4 5 786d 850d 0/3 auto-obsoleted due to no activity on 2023/09/28 05:53

Sample crash report:
loop0: detected capacity change from 0 to 64
======================================================
WARNING: possible circular locking dependency detected
6.1.146-syzkaller #0 Not tainted
------------------------------------------------------
syz.0.20/4429 is trying to acquire lock:
ffff88805d4f1af8 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xd7/0x1280 fs/hfs/extent.c:397

but task is already holding lock:
ffff88801e30c0b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x15b/0x1d0 fs/hfs/bfind.c:-1

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&tree->tree_lock/1){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747
       hfs_find_init+0x15b/0x1d0 fs/hfs/bfind.c:-1
       hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
       hfs_extend_file+0x2eb/0x1280 fs/hfs/extent.c:401
       hfs_bmap_reserve+0x103/0x420 fs/hfs/btree.c:234
       hfs_cat_create+0x1c0/0x8d0 fs/hfs/catalog.c:104
       hfs_create+0x62/0xd0 fs/hfs/dir.c:202
       lookup_open fs/namei.c:3482 [inline]
       open_last_lookups fs/namei.c:3550 [inline]
       path_openat+0x1187/0x2e70 fs/namei.c:3780
       do_filp_open+0x1c1/0x3c0 fs/namei.c:3810
       do_sys_openat2+0x142/0x490 fs/open.c:1318
       do_sys_open fs/open.c:1334 [inline]
       __do_sys_openat fs/open.c:1350 [inline]
       __se_sys_openat fs/open.c:1345 [inline]
       __x64_sys_openat+0x135/0x160 fs/open.c:1345
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&HFS_I(tree->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 kernel/locking/lockdep.c:3825 [inline]
       __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049
       lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747
       hfs_extend_file+0xd7/0x1280 fs/hfs/extent.c:397
       hfs_bmap_reserve+0x103/0x420 fs/hfs/btree.c:234
       __hfs_ext_write_extent+0x1fa/0x470 fs/hfs/extent.c:121
       hfs_ext_write_extent+0x15e/0x1e0 fs/hfs/extent.c:144
       hfs_write_inode+0x8e/0x970 fs/hfs/inode.c:434
       write_inode fs/fs-writeback.c:1460 [inline]
       __writeback_single_inode+0x75b/0x1160 fs/fs-writeback.c:1677
       writeback_single_inode+0x221/0x8b0 fs/fs-writeback.c:1733
       write_inode_now+0x15d/0x1d0 fs/fs-writeback.c:2769
       hfs_file_fsync+0xa3/0x140 fs/hfs/inode.c:682
       generic_write_sync include/linux/fs.h:2962 [inline]
       generic_file_write_iter+0x25d/0x2e0 mm/filemap.c:4010
       call_write_iter include/linux/fs.h:2265 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x44c/0x960 fs/read_write.c:584
       ksys_write+0x143/0x240 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x4c/0xa0 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(&HFS_I(tree->inode)->extents_lock);
                               lock(&tree->tree_lock/1);
  lock(&HFS_I(tree->inode)->extents_lock);

 *** DEADLOCK ***

3 locks held by syz.0.20/4429:
 #0: ffff888078eac460 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x256/0x960 fs/read_write.c:580
 #1: ffff88805d4f3028 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #1: ffff88805d4f3028 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: hfs_file_fsync+0x99/0x140 fs/hfs/inode.c:679
 #2: ffff88801e30c0b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfs_find_init+0x15b/0x1d0 fs/hfs/bfind.c:-1

stack backtrace:
CPU: 0 PID: 4429 Comm: syz.0.20 Not tainted 6.1.146-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 check_noncircular+0x274/0x310 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 kernel/locking/lockdep.c:3825 [inline]
 __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049
 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747
 hfs_extend_file+0xd7/0x1280 fs/hfs/extent.c:397
 hfs_bmap_reserve+0x103/0x420 fs/hfs/btree.c:234
 __hfs_ext_write_extent+0x1fa/0x470 fs/hfs/extent.c:121
 hfs_ext_write_extent+0x15e/0x1e0 fs/hfs/extent.c:144
 hfs_write_inode+0x8e/0x970 fs/hfs/inode.c:434
 write_inode fs/fs-writeback.c:1460 [inline]
 __writeback_single_inode+0x75b/0x1160 fs/fs-writeback.c:1677
 writeback_single_inode+0x221/0x8b0 fs/fs-writeback.c:1733
 write_inode_now+0x15d/0x1d0 fs/fs-writeback.c:2769
 hfs_file_fsync+0xa3/0x140 fs/hfs/inode.c:682
 generic_write_sync include/linux/fs.h:2962 [inline]
 generic_file_write_iter+0x25d/0x2e0 mm/filemap.c:4010
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x44c/0x960 fs/read_write.c:584
 ksys_write+0x143/0x240 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f63b338e9a9
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:00007ffcfd7cd368 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f63b35b5fa0 RCX: 00007f63b338e9a9
RDX: 0000000000001006 RSI: 0000200000000940 RDI: 0000000000000008
RBP: 00007f63b3410d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f63b35b5fa0 R14: 00007f63b35b5fa0 R15: 0000000000000003
 </TASK>

Crashes (119):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/21 03:07 linux-6.1.y 3369c6df2fae 7117feec .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/08/08 14:53 linux-6.1.y 3594f306da12 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/08/08 08:09 linux-6.1.y 3594f306da12 6a893178 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/08/05 00:39 linux-6.1.y 3594f306da12 f5bcc8dc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/08/04 23:11 linux-6.1.y 3594f306da12 f5bcc8dc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/07/26 20:27 linux-6.1.y 3594f306da12 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/07/23 22:47 linux-6.1.y 3369c6df2fae 0c1d6ded .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/07/21 01:21 linux-6.1.y 3369c6df2fae 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/07/18 07:07 linux-6.1.y 3369c6df2fae 88248e14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/07/14 11:21 linux-6.1.y dfc486ec9cce d8fc7335 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/07/03 10:24 linux-6.1.y 7e69c33e4858 115ceea7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/07/03 04:46 linux-6.1.y 7e69c33e4858 115ceea7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/06/02 07:39 linux-6.1.y da3c5173c55f 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/06/01 02:29 linux-6.1.y da3c5173c55f 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/05/31 01:50 linux-6.1.y da3c5173c55f 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/05/26 21:53 linux-6.1.y da3c5173c55f 874a1386 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/05/10 18:31 linux-6.1.y 02b72ccb5f9d 77908e5f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/05/10 18:31 linux-6.1.y 02b72ccb5f9d 77908e5f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/05/02 08:00 linux-6.1.y b6736e03756f 51b137cd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/04/19 16:24 linux-6.1.y 420102835862 2a20f901 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/04/15 11:01 linux-6.1.y 420102835862 23b969b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/04/15 06:34 linux-6.1.y 420102835862 0bd6db41 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/04/11 20:56 linux-6.1.y 420102835862 0bd6db41 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/04/09 23:51 linux-6.1.y 3dfebb87d7eb 988b336c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/04/09 10:54 linux-6.1.y 3dfebb87d7eb 47d015b1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/04/07 10:14 linux-6.1.y 3dfebb87d7eb 1c65791e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/04/07 10:14 linux-6.1.y 3dfebb87d7eb 1c65791e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/04/01 02:52 linux-6.1.y 8e60a714ba3b 36d76a97 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/03/29 17:59 linux-6.1.y 8e60a714ba3b d3999433 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/03/29 05:26 linux-6.1.y 8e60a714ba3b cf25e2c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/03/28 23:25 linux-6.1.y 8e60a714ba3b 9a1a9e31 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/02/26 06:39 linux-6.1.y 3a8358583626 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/01/14 08:20 linux-6.1.y c63962be84ef b1f1cd88 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/01/14 02:04 linux-6.1.y c63962be84ef b1f1cd88 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/01/01 00:58 linux-6.1.y 563edd786f0a d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in hfs_extend_file
2025/08/02 19:01 linux-6.1.y 3594f306da12 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in hfs_extend_file
2025/08/01 17:56 linux-6.1.y 3594f306da12 40127d41 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in hfs_extend_file
2025/07/21 07:06 linux-6.1.y 3369c6df2fae 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in hfs_extend_file
2025/07/14 23:57 linux-6.1.y f2198ea7eb3e d8fc7335 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in hfs_extend_file
2025/07/11 10:17 linux-6.1.y dfc486ec9cce 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in hfs_extend_file
2025/06/30 21:35 linux-6.1.y 7e69c33e4858 6e83b42d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in hfs_extend_file
2025/06/26 04:12 linux-6.1.y 58485ff1a74f 26d77996 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in hfs_extend_file
2025/06/17 08:56 linux-6.1.y 58485ff1a74f cfebc887 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in hfs_extend_file
2025/06/16 18:44 linux-6.1.y 58485ff1a74f d1716036 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in hfs_extend_file
2025/05/19 04:07 linux-6.1.y 325285d9fc86 f41472b0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in hfs_extend_file
2025/05/13 11:42 linux-6.1.y 02b72ccb5f9d f6671af7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in hfs_extend_file
2025/05/12 01:11 linux-6.1.y 02b72ccb5f9d 77908e5f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in hfs_extend_file
2025/05/07 17:50 linux-6.1.y ac7079a42ea5 dbf35fa1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in hfs_extend_file
2025/05/03 21:41 linux-6.1.y b6736e03756f b0714e37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in hfs_extend_file
2025/04/22 21:10 linux-6.1.y 420102835862 53a8b9bd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in hfs_extend_file
2025/04/02 20:52 linux-6.1.y 8e60a714ba3b c799dfdd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in hfs_extend_file
2025/03/11 11:30 linux-6.1.y 6ae7ac5c4251 16256247 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in hfs_extend_file
2025/03/11 10:16 linux-6.1.y 6ae7ac5c4251 16256247 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in hfs_extend_file
2025/02/08 23:55 linux-6.1.y 0cbb5f65e52f ef44b750 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in hfs_extend_file
2025/01/15 11:12 linux-6.1.y c63962be84ef 7315a7cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in hfs_extend_file
2025/01/09 01:11 linux-6.1.y 7dc732d24ff7 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in hfs_extend_file
2024/04/04 03:10 linux-6.1.y 347385861c50 51c4dcff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in hfs_extend_file
* Struck through repros no longer work on HEAD.