[syzbot] [hfs?] KASAN: out-of-bounds Read in hfs_bnode_move

[syzbot] [hfs?] KASAN: out-of-bounds Read in hfs_bnode_move

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    89be9a83ccf1 Linux 6.16-rc7
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17ac1b82580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8adfe52da0de2761
dashboard link: https://syzkaller.appspot.com/bug?extid=41ba9c82bce8d7101765
compiler:       Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1771ef22580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11f764f0580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-89be9a83.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a3f5f507f252/vmlinux-89be9a83.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a8f9b92c57a6/bzImage-89be9a83.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/f02d92e4771f/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+41ba9c82bce8d7101765@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 64
==================================================================
BUG: KASAN: out-of-bounds in hfs_bnode_move+0xea/0x130 fs/hfs/bnode.c:143
Read of size 18446744073709486080 at addr ffff888000994400 by task syz.0.16/5547

CPU: 0 UID: 0 PID: 5547 Comm: syz.0.16 Not tainted 6.16.0-rc7-syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x230 mm/kasan/report.c:480
 kasan_report+0x118/0x150 mm/kasan/report.c:593
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:189
 __asan_memmove+0x29/0x70 mm/kasan/shadow.c:94
 hfs_bnode_move+0xea/0x130 fs/hfs/bnode.c:143
 hfs_brec_remove+0x467/0x550 fs/hfs/brec.c:222
 hfs_cat_move+0x6fb/0x960 fs/hfs/catalog.c:364
 hfs_rename+0x1dc/0x2d0 fs/hfs/dir.c:299
 vfs_rename+0xb99/0xec0 fs/namei.c:5137
 do_renameat2+0x878/0xc50 fs/namei.c:5286
 __do_sys_rename fs/namei.c:5333 [inline]
 __se_sys_rename fs/namei.c:5331 [inline]
 __x64_sys_rename+0x82/0x90 fs/namei.c:5331
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f11db18e9a9
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:00007ffd56ec9fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 00007f11db3b5fa0 RCX: 00007f11db18e9a9
RDX: 0000000000000000 RSI: 0000200000000780 RDI: 00002000000003c0
RBP: 00007f11db210d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f11db3b5fa0 R14: 00007f11db3b5fa0 R15: 0000000000000002
 </TASK>

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x35 pfn:0x994
memcg:ffff888030a98000
anon flags: 0x7ff00000020908(uptodate|active|owner_2|swapbacked|node=0|zone=0|lastcpupid=0x7ff)
raw: 007ff00000020908 0000000000000000 dead000000000122 ffff888059a96cc1
raw: 0000000000000035 0000000000000000 00000001ffffffff ffff888030a98000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Movable, gfp_mask 0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), pid 5548, tgid 5548 (dhcpcd-run-hook), ts 123108746961, free_ts 121368908469
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704
 prep_new_page mm/page_alloc.c:1712 [inline]
 get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3669
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419
 folio_alloc_mpol_noprof mm/mempolicy.c:2438 [inline]
 vma_alloc_folio_noprof+0xe4/0x200 mm/mempolicy.c:2473
 folio_prealloc+0x30/0x180 mm/memory.c:-1
 wp_page_copy mm/memory.c:3569 [inline]
 do_wp_page+0x1231/0x5800 mm/memory.c:4030
 handle_pte_fault mm/memory.c:6085 [inline]
 __handle_mm_fault+0x1144/0x5620 mm/memory.c:6212
 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6381
 do_user_addr_fault+0xa81/0x1390 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
page last free pid 5509 tgid 5509 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1248 [inline]
 free_unref_folios+0xc66/0x14d0 mm/page_alloc.c:2763
 folios_put_refs+0x559/0x640 mm/swap.c:992
 free_pages_and_swap_cache+0x4be/0x520 mm/swap_state.c:267
 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline]
 tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:397 [inline]
 tlb_flush_mmu+0x3a0/0x680 mm/mmu_gather.c:404
 tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497
 exit_mmap+0x44c/0xb50 mm/mmap.c:1297
 __mmput+0x118/0x420 kernel/fork.c:1121
 exit_mm+0x1da/0x2c0 kernel/exit.c:581
 do_exit+0x648/0x22e0 kernel/exit.c:952
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1105
 __do_sys_exit_group kernel/exit.c:1116 [inline]
 __se_sys_exit_group kernel/exit.c:1114 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1114
 x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888000994300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888000994380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888000994400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                   ^
 ffff888000994480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888000994500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================


---
This report is generated by a bot. It may contain errors.
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If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
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If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
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If the report is a duplicate of another one, reply with:
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If you want to undo deduplication, reply with:
#syz undup

Re: [syzbot] [hfs?] KASAN: out-of-bounds Read in hfs_bnode_move

[Viacheslav Dubeyko]

On Wed, 2025-07-23 at 10:18 -0700, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 

Issue has been created:
https://github.com/hfs-linux-kernel/hfs-linux-kernel/issues/227

Thanks,
Slava.

> HEAD commit:    89be9a83ccf1 Linux 6.16-rc7
> git tree:       upstream
> console output:
> https://syzkaller.appspot.com/x/log.txt?x=17ac1b82580000
> kernel config: 
> https://syzkaller.appspot.com/x/.config?x=8adfe52da0de2761
> dashboard link:
> https://syzkaller.appspot.com/bug?extid=41ba9c82bce8d7101765
> compiler:       Debian clang version 20.1.7
> (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD
> 20.1.7
> syz repro:     
> https://syzkaller.appspot.com/x/repro.syz?x=1771ef22580000
> C reproducer:  
> https://syzkaller.appspot.com/x/repro.c?x=11f764f0580000
> 
> Downloadable assets:
> disk image (non-bootable):
> https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-89be9a83.raw.xz
> vmlinux:
> https://storage.googleapis.com/syzbot-assets/a3f5f507f252/vmlinux-89be9a83.xz
> kernel image:
> https://storage.googleapis.com/syzbot-assets/a8f9b92c57a6/bzImage-89be9a83.xz
> mounted in repro:
> https://storage.googleapis.com/syzbot-assets/f02d92e4771f/mount_0.gz
> 
> IMPORTANT: if you fix the issue, please add the following tag to the
> commit:
> Reported-by: syzbot+41ba9c82bce8d7101765@syzkaller.appspotmail.com
> 
> loop0: detected capacity change from 0 to 64
> ==================================================================
> BUG: KASAN: out-of-bounds in hfs_bnode_move+0xea/0x130
> fs/hfs/bnode.c:143
> Read of size 18446744073709486080 at addr ffff888000994400 by task
> syz.0.16/5547
> 
> CPU: 0 UID: 0 PID: 5547 Comm: syz.0.16 Not tainted 6.16.0-rc7-
> syzkaller #0 PREEMPT(full) 
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-
> debian-1.16.3-2~bpo12+1 04/01/2014
> Call Trace:
>  <TASK>
>  dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
>  print_address_description mm/kasan/report.c:378 [inline]
>  print_report+0xca/0x230 mm/kasan/report.c:480
>  kasan_report+0x118/0x150 mm/kasan/report.c:593
>  check_region_inline mm/kasan/generic.c:-1 [inline]
>  kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:189
>  __asan_memmove+0x29/0x70 mm/kasan/shadow.c:94
>  hfs_bnode_move+0xea/0x130 fs/hfs/bnode.c:143
>  hfs_brec_remove+0x467/0x550 fs/hfs/brec.c:222
>  hfs_cat_move+0x6fb/0x960 fs/hfs/catalog.c:364
>  hfs_rename+0x1dc/0x2d0 fs/hfs/dir.c:299
>  vfs_rename+0xb99/0xec0 fs/namei.c:5137
>  do_renameat2+0x878/0xc50 fs/namei.c:5286
>  __do_sys_rename fs/namei.c:5333 [inline]
>  __se_sys_rename fs/namei.c:5331 [inline]
>  __x64_sys_rename+0x82/0x90 fs/namei.c:5331
>  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>  do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> RIP: 0033:0x7f11db18e9a9
> 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:00007ffd56ec9fe8 EFLAGS: 00000246 ORIG_RAX:
> 0000000000000052
> RAX: ffffffffffffffda RBX: 00007f11db3b5fa0 RCX: 00007f11db18e9a9
> RDX: 0000000000000000 RSI: 0000200000000780 RDI: 00002000000003c0
> RBP: 00007f11db210d69 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 00007f11db3b5fa0 R14: 00007f11db3b5fa0 R15: 0000000000000002
>  </TASK>
> 
> The buggy address belongs to the physical page:
> page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x35
> pfn:0x994
> memcg:ffff888030a98000
> anon flags:
> 0x7ff00000020908(uptodate|active|owner_2|swapbacked|node=0|zone=0|las
> tcpupid=0x7ff)
> raw: 007ff00000020908 0000000000000000 dead000000000122
> ffff888059a96cc1
> raw: 0000000000000035 0000000000000000 00000001ffffffff
> ffff888030a98000
> page dumped because: kasan: bad access detected
> page_owner tracks the page as allocated
> page last allocated via order 0, migratetype Movable, gfp_mask
> 0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), pid 5548, tgid 5548
> (dhcpcd-run-hook), ts 123108746961, free_ts 121368908469
>  set_page_owner include/linux/page_owner.h:32 [inline]
>  post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704
>  prep_new_page mm/page_alloc.c:1712 [inline]
>  get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3669
>  __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959
>  alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419
>  folio_alloc_mpol_noprof mm/mempolicy.c:2438 [inline]
>  vma_alloc_folio_noprof+0xe4/0x200 mm/mempolicy.c:2473
>  folio_prealloc+0x30/0x180 mm/memory.c:-1
>  wp_page_copy mm/memory.c:3569 [inline]
>  do_wp_page+0x1231/0x5800 mm/memory.c:4030
>  handle_pte_fault mm/memory.c:6085 [inline]
>  __handle_mm_fault+0x1144/0x5620 mm/memory.c:6212
>  handle_mm_fault+0x40a/0x8e0 mm/memory.c:6381
>  do_user_addr_fault+0xa81/0x1390 arch/x86/mm/fault.c:1336
>  handle_page_fault arch/x86/mm/fault.c:1476 [inline]
>  exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532
>  asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
> page last free pid 5509 tgid 5509 stack trace:
>  reset_page_owner include/linux/page_owner.h:25 [inline]
>  free_pages_prepare mm/page_alloc.c:1248 [inline]
>  free_unref_folios+0xc66/0x14d0 mm/page_alloc.c:2763
>  folios_put_refs+0x559/0x640 mm/swap.c:992
>  free_pages_and_swap_cache+0x4be/0x520 mm/swap_state.c:267
>  __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline]
>  tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
>  tlb_flush_mmu_free mm/mmu_gather.c:397 [inline]
>  tlb_flush_mmu+0x3a0/0x680 mm/mmu_gather.c:404
>  tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497
>  exit_mmap+0x44c/0xb50 mm/mmap.c:1297
>  __mmput+0x118/0x420 kernel/fork.c:1121
>  exit_mm+0x1da/0x2c0 kernel/exit.c:581
>  do_exit+0x648/0x22e0 kernel/exit.c:952
>  do_group_exit+0x21c/0x2d0 kernel/exit.c:1105
>  __do_sys_exit_group kernel/exit.c:1116 [inline]
>  __se_sys_exit_group kernel/exit.c:1114 [inline]
>  __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1114
>  x64_sys_call+0x21ba/0x21c0
> arch/x86/include/generated/asm/syscalls_64.h:232
>  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>  do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> 
> Memory state around the buggy address:
>  ffff888000994300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>  ffff888000994380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > ffff888000994400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>                    ^
>  ffff888000994480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>  ffff888000994500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> ==================================================================
> 
> 
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
> 
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> 
> If the report is already addressed, let syzbot know by replying with:
> #syz fix: exact-commit-title
> 
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before
> testing.
> 
> If you want to overwrite report's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
> 
> If the report is a duplicate of another one, reply with:
> #syz dup: exact-subject-of-another-report
> 
> If you want to undo deduplication, reply with:
> #syz undup

[PATCH] hfs: Prevent the use of bnodes without entries

[Edward Adam Davis]

If the number of entries in the bnode is 0, the bnode is considered
invalid.

Reported-by: syzbot+41ba9c82bce8d7101765@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=41ba9c82bce8d7101765
Tested-by: syzbot+41ba9c82bce8d7101765@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
---
 fs/hfs/bfind.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/hfs/bfind.c b/fs/hfs/bfind.c
index ef9498a6e88a..1d6f2bbafa7a 100644
--- a/fs/hfs/bfind.c
+++ b/fs/hfs/bfind.c
@@ -133,6 +133,8 @@ int hfs_brec_find(struct hfs_find_data *fd)
 			goto invalid;
 		if (bnode->type != (--height ? HFS_NODE_INDEX : HFS_NODE_LEAF))
 			goto invalid;
+		if (!bnode->num_recs)
+			goto invalid;
 		bnode->parent = parent;
 
 		res = __hfs_brec_find(bnode, fd);
-- 
2.43.0

Re: [PATCH] hfs: Prevent the use of bnodes without entries

[Viacheslav Dubeyko]

On Thu, 2025-07-24 at 23:08 +0800, Edward Adam Davis wrote:
> If the number of entries in the bnode is 0, the bnode is considered
> invalid.
> 
> Reported-by: syzbot+41ba9c82bce8d7101765@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=41ba9c82bce8d7101765  
> Tested-by: syzbot+41ba9c82bce8d7101765@syzkaller.appspotmail.com
> Signed-off-by: Edward Adam Davis <eadavis@qq.com>
> ---
>  fs/hfs/bfind.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/fs/hfs/bfind.c b/fs/hfs/bfind.c
> index ef9498a6e88a..1d6f2bbafa7a 100644
> --- a/fs/hfs/bfind.c
> +++ b/fs/hfs/bfind.c
> @@ -133,6 +133,8 @@ int hfs_brec_find(struct hfs_find_data *fd)
>  			goto invalid;
>  		if (bnode->type != (--height ? HFS_NODE_INDEX : HFS_NODE_LEAF))
>  			goto invalid;
> +		if (!bnode->num_recs)
> +			goto invalid;

If b-tree node hasn't records, then it doesn't mean that it's invalid. Because,
if we go into invalid way, then we show the message that node is corrupted [1]:

invalid:
	pr_err("inconsistency in B*Tree (%d,%d,%d,%u,%u)\n",
	       height, bnode->height, bnode->type, nidx, parent);
	res = -EIO;

But it is not true because the node simply has no records. It could be invalid
if bnode->num_recs < 0.

Also, I've sent the patch [2] already. I believe it should fix the issue. Am I
wrong here?

Thanks,
Slava.

[1] https://elixir.bootlin.com/linux/v6.16-rc6/source/fs/hfs/bfind.c#L152
[2]
https://lore.kernel.org/linux-fsdevel/20250703214912.244138-1-slava@dubeyko.com/

>  		bnode->parent = parent;
>  
>  		res = __hfs_brec_find(bnode, fd);

Re: [syzbot] [hfs?] KASAN: out-of-bounds Read in hfs_bnode_move

[syzbot]

syzbot suspects this issue was fixed by commit:

commit 736a0516a16268995f4898eded49bfef077af709
Author: Viacheslav Dubeyko <slava@dubeyko.com>
Date:   Thu Jul 10 21:36:57 2025 +0000

    hfs: fix general protection fault in hfs_find_init()

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=1519c634580000
start commit:   01a412d06bc5 Merge tag 'pull-ufs-fix' of git://git.kernel...
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=859f36d9ccbeaa3e
dashboard link: https://syzkaller.appspot.com/bug?extid=41ba9c82bce8d7101765
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=15611b82580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=117cff22580000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: hfs: fix general protection fault in hfs_find_init()

For information about bisection process see: https://goo.gl/tpsmEJ#bisection