syzbot


possible deadlock in hfs_extend_file (3)

Status: upstream: reported on 2024/03/13 05:11
Reported-by: syzbot+033048aa2a56eacb2789@syzkaller.appspotmail.com
First crash: 538d, last: 1d18h
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 979d 979d 0/1 upstream: reported on 2022/12/27 15:22
linux-5.15 possible deadlock in hfs_extend_file (2) 4 1 679d 679d 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 717d 903d 0/3 auto-obsoleted due to no activity on 2023/12/24 21:20
upstream possible deadlock in hfs_extend_file hfs 4 46 740d 984d 0/29 auto-obsoleted due to no activity on 2023/11/06 09:48
linux-6.1 possible deadlock in hfs_extend_file (2) origin:upstream 4 C 123 6d14h 516d 0/3 upstream: reported C repro on 2024/04/04 03:11
upstream possible deadlock in hfs_extend_file (3) hfs 4 C unreliable 2444 11h01m 501d 0/29 upstream: reported C repro on 2024/04/18 14:41
linux-6.6 possible deadlock in hfs_extend_file origin:upstream missing-backport 4 C 25 3d06h 76d 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 609d 629d 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 805d 868d 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
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.1709/13191 is trying to acquire lock:
ffff88801f32ae78 (&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:
ffff8880659ca0b0 (&tree->tree_lock#2/1){+.+.}-{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#2/1){+.+.}-{3:3}:
       __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
       hfs_find_init+0x15b/0x1d0 fs/hfs/bfind.c:-1
       hfs_ext_read_extent fs/hfs/extent.c:200 [inline]
       hfs_get_block+0x518/0xbd0 fs/hfs/extent.c:366
       block_read_full_page+0x2e8/0xd10 fs/buffer.c:2290
       do_read_cache_page+0x8a1/0x1030 mm/filemap.c:-1
       read_mapping_page include/linux/pagemap.h:515 [inline]
       __hfs_bnode_create+0x4f0/0xba0 fs/hfs/bnode.c:395
       hfs_bnode_find+0x220/0xce0 fs/hfs/bnode.c:444
       hfs_brec_find+0x156/0x500 fs/hfs/bfind.c:126
       hfs_brec_read+0x20/0x100 fs/hfs/bfind.c:165
       hfs_cat_find_brec+0x159/0x3f0 fs/hfs/catalog.c:194
       hfs_fill_super+0xeb4/0x13f0 fs/hfs/super.c:419
       mount_bdev+0x287/0x3c0 fs/super.c:1400
       legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
       vfs_get_tree+0x88/0x270 fs/super.c:1530
       do_new_mount+0x24a/0xa40 fs/namespace.c:3025
       do_mount fs/namespace.c:3368 [inline]
       __do_sys_mount fs/namespace.c:3576 [inline]
       __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3553
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #0 (&HFS_I(tree->inode)->extents_lock){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain kernel/locking/lockdep.c:3788 [inline]
       __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012
       lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
       __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
       hfs_extend_file+0xd7/0x1280 fs/hfs/extent.c:397
       hfs_bmap_reserve+0x103/0x420 fs/hfs/btree.c:231
       __hfs_ext_write_extent+0x1fa/0x470 fs/hfs/extent.c:121
       __hfs_ext_cache_extent+0x6b/0x9b0 fs/hfs/extent.c:174
       hfs_ext_read_extent fs/hfs/extent.c:202 [inline]
       hfs_extend_file+0x313/0x1280 fs/hfs/extent.c:401
       hfs_get_block+0x3d4/0xbd0 fs/hfs/extent.c:353
       __block_write_begin_int+0x54e/0x15a0 fs/buffer.c:2012
       __block_write_begin fs/buffer.c:2062 [inline]
       block_write_begin fs/buffer.c:2122 [inline]
       cont_write_begin+0x58a/0x7b0 fs/buffer.c:2471
       hfs_write_begin+0x92/0xe0 fs/hfs/inode.c:59
       cont_expand_zero fs/buffer.c:2398 [inline]
       cont_write_begin+0x26c/0x7b0 fs/buffer.c:2461
       hfs_write_begin+0x92/0xe0 fs/hfs/inode.c:59
       hfs_file_truncate+0x18f/0x9c0 fs/hfs/extent.c:494
       hfs_inode_setattr+0x4ab/0x6f0 fs/hfs/inode.c:657
       notify_change+0xbcd/0xee0 fs/attr.c:505
       do_truncate+0x197/0x220 fs/open.c:65
       do_sys_ftruncate+0x31b/0x3d0 fs/open.c:193
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&tree->tree_lock#2/1);
                               lock(&HFS_I(tree->inode)->extents_lock);
                               lock(&tree->tree_lock#2/1);
  lock(&HFS_I(tree->inode)->extents_lock);

 *** DEADLOCK ***

4 locks held by syz.0.1709/13191:
 #0: ffff8880659c8460 (sb_writers#24){.+.+}-{0:0}, at: do_sys_ftruncate+0x284/0x3d0 fs/open.c:190
 #1: ffff88801f328928 (&sb->s_type->i_mutex_key#32){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff88801f328928 (&sb->s_type->i_mutex_key#32){+.+.}-{3:3}, at: do_truncate+0x183/0x220 fs/open.c:63
 #2: ffff88801f328778 (&HFS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfs_extend_file+0xd7/0x1280 fs/hfs/extent.c:397
 #3: ffff8880659ca0b0 (&tree->tree_lock#2/1){+.+.}-{3:3}, at: hfs_find_init+0x15b/0x1d0 fs/hfs/bfind.c:-1

stack backtrace:
CPU: 1 PID: 13191 Comm: syz.0.1709 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain kernel/locking/lockdep.c:3788 [inline]
 __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012
 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
 __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 hfs_extend_file+0xd7/0x1280 fs/hfs/extent.c:397
 hfs_bmap_reserve+0x103/0x420 fs/hfs/btree.c:231
 __hfs_ext_write_extent+0x1fa/0x470 fs/hfs/extent.c:121
 __hfs_ext_cache_extent+0x6b/0x9b0 fs/hfs/extent.c:174
 hfs_ext_read_extent fs/hfs/extent.c:202 [inline]
 hfs_extend_file+0x313/0x1280 fs/hfs/extent.c:401
 hfs_get_block+0x3d4/0xbd0 fs/hfs/extent.c:353
 __block_write_begin_int+0x54e/0x15a0 fs/buffer.c:2012
 __block_write_begin fs/buffer.c:2062 [inline]
 block_write_begin fs/buffer.c:2122 [inline]
 cont_write_begin+0x58a/0x7b0 fs/buffer.c:2471
 hfs_write_begin+0x92/0xe0 fs/hfs/inode.c:59
 cont_expand_zero fs/buffer.c:2398 [inline]
 cont_write_begin+0x26c/0x7b0 fs/buffer.c:2461
 hfs_write_begin+0x92/0xe0 fs/hfs/inode.c:59
 hfs_file_truncate+0x18f/0x9c0 fs/hfs/extent.c:494
 hfs_inode_setattr+0x4ab/0x6f0 fs/hfs/inode.c:657
 notify_change+0xbcd/0xee0 fs/attr.c:505
 do_truncate+0x197/0x220 fs/open.c:65
 do_sys_ftruncate+0x31b/0x3d0 fs/open.c:193
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f47bc920be9
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:00007f47bab88038 EFLAGS: 00000246 ORIG_RAX: 000000000000004d
RAX: ffffffffffffffda RBX: 00007f47bcb57fa0 RCX: 00007f47bc920be9
RDX: 0000000000000000 RSI: 0000000000008979 RDI: 0000000000000004
RBP: 00007f47bc9a3e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f47bcb58038 R14: 00007f47bcb57fa0 R15: 00007ffc6b733698
 </TASK>

Crashes (158):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/31 12:50 linux-5.15.y 01879f56bdde 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2025/08/27 17:10 linux-5.15.y c79648372d02 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2025/08/22 10:00 linux-5.15.y c79648372d02 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2025/08/08 14:57 linux-5.15.y c79648372d02 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2025/07/28 22:14 linux-5.15.y c79648372d02 6654ea9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2025/07/27 09:00 linux-5.15.y c79648372d02 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2025/07/20 17:34 linux-5.15.y c79648372d02 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2025/07/16 20:30 linux-5.15.y 89950c454265 44f8051e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2025/06/14 16:58 linux-5.15.y 1c700860e8bc 5f4b362d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2025/06/03 21:57 linux-5.15.y 98f47d0e9b8c a30356b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2025/05/29 08:38 linux-5.15.y 98f47d0e9b8c 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2025/05/25 19:21 linux-5.15.y 98f47d0e9b8c 2d4582d0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2025/05/22 01:41 linux-5.15.y a68c15152131 0919b50b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2025/05/20 12:24 linux-5.15.y a68c15152131 b47f9e02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2025/05/18 07:47 linux-5.15.y a68c15152131 f41472b0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2025/05/17 21:29 linux-5.15.y 3b8db0e4f263 f41472b0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2025/05/13 19:47 linux-5.15.y 3b8db0e4f263 7344edeb .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2025/05/12 02:38 linux-5.15.y 3b8db0e4f263 77908e5f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2025/05/09 09:17 linux-5.15.y 3b8db0e4f263 bb813bcc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2025/04/17 16:24 linux-5.15.y f7347f400572 229db4cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2025/04/03 18:35 linux-5.15.y 0c935c049b5c d7ae3a11 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2025/04/03 14:55 linux-5.15.y 0c935c049b5c 996a9618 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2025/02/05 12:12 linux-5.15.y c16c81c81336 5896748e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2025/01/27 02:03 linux-5.15.y 003148680b79 9fbd772e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2025/01/20 01:09 linux-5.15.y 4735586da88e f2cb035c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2024/03/13 05:10 linux-5.15.y 574362648507 db5b7ff0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hfs_extend_file
2025/08/05 10:16 linux-5.15.y c79648372d02 37880f40 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in hfs_extend_file
2025/07/22 19:54 linux-5.15.y c79648372d02 8e9d1dc1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in hfs_extend_file
2025/07/19 00:55 linux-5.15.y c79648372d02 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in hfs_extend_file
2025/06/18 14:25 linux-5.15.y 1c700860e8bc ed3e87f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in hfs_extend_file
2025/06/18 00:25 linux-5.15.y 1c700860e8bc e77fae15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in hfs_extend_file
2025/05/30 22:36 linux-5.15.y 98f47d0e9b8c 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in hfs_extend_file
2025/05/19 16:08 linux-5.15.y a68c15152131 b84f0537 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in hfs_extend_file
2025/05/16 05:11 linux-5.15.y 3b8db0e4f263 cfde8269 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in hfs_extend_file
2025/05/12 06:57 linux-5.15.y 3b8db0e4f263 77908e5f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in hfs_extend_file
2025/05/10 18:33 linux-5.15.y 3b8db0e4f263 77908e5f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in hfs_extend_file
2025/05/01 02:08 linux-5.15.y f7347f400572 ce7952f4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in hfs_extend_file
2025/04/27 11:55 linux-5.15.y f7347f400572 c6b4fb39 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in hfs_extend_file
2025/04/11 17:47 linux-5.15.y f7347f400572 94486846 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in hfs_extend_file
2025/04/11 05:34 linux-5.15.y f7347f400572 94486846 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in hfs_extend_file
2025/04/10 17:14 linux-5.15.y f7347f400572 1ef3ab4d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in hfs_extend_file
2025/04/09 10:49 linux-5.15.y 0c935c049b5c 47d015b1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in hfs_extend_file
2025/03/30 10:30 linux-5.15.y 0c935c049b5c d3999433 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in hfs_extend_file
2025/02/17 00:24 linux-5.15.y c16c81c81336 40a34ec9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in hfs_extend_file
2025/02/04 05:41 linux-5.15.y c16c81c81336 8f267cef .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in hfs_extend_file
2025/01/19 13:13 linux-5.15.y 4735586da88e f2cb035c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in hfs_extend_file
2025/01/15 06:19 linux-5.15.y 4735586da88e 7315a7cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in hfs_extend_file
2025/01/14 06:05 linux-5.15.y 4735586da88e b1f1cd88 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in hfs_extend_file
2025/01/09 09:20 linux-5.15.y 91786f140358 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 possible deadlock in hfs_extend_file
* Struck through repros no longer work on HEAD.