[syzbot] KASAN: slab-out-of-bounds Read in __hfs_brec_find

From: syzbot
Date: Mon Nov 28 2022 - 05:01:54 EST

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Hello,

syzbot found the following issue on:

HEAD commit: 644e9524388a Merge tag 'for-v6.1-rc' of git://git.kernel.o..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=13139a87880000
kernel config: https://syzkaller.appspot.com/x/.config?x=8d01b6e3197974dd
dashboard link: https://syzkaller.appspot.com/bug?extid=e836ff7133ac02be825f
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17a6d5bb880000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14212d8d880000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0968428e17b4/disk-644e9524.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/fd4c3bfd0777/vmlinux-644e9524.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ee4571f27f1c/bzImage-644e9524.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/97e079d270b2/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e836ff7133ac02be825f@xxxxxxxxxxxxxxxxxxxxxxxxx

==================================================================
BUG: KASAN: slab-out-of-bounds in hfs_strcmp+0x117/0x190 fs/hfs/string.c:84
Read of size 1 at addr ffff88807eb62c4e by task kworker/u4:1/11

CPU: 1 PID: 11 Comm: kworker/u4:1 Not tainted 6.1.0-rc6-syzkaller-00308-g644e9524388a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106
print_address_description+0x74/0x340 mm/kasan/report.c:284
print_report+0x107/0x1f0 mm/kasan/report.c:395
kasan_report+0xcd/0x100 mm/kasan/report.c:495
hfs_strcmp+0x117/0x190 fs/hfs/string.c:84
__hfs_brec_find+0x213/0x5c0 fs/hfs/bfind.c:75
hfs_brec_find+0x276/0x520 fs/hfs/bfind.c:138
hfs_write_inode+0x34c/0xb40 fs/hfs/inode.c:462
write_inode fs/fs-writeback.c:1440 [inline]
__writeback_single_inode+0x4d6/0x670 fs/fs-writeback.c:1652
writeback_sb_inodes+0xb3b/0x18f0 fs/fs-writeback.c:1878
wb_writeback+0x41f/0x7b0 fs/fs-writeback.c:2052
wb_do_writeback fs/fs-writeback.c:2195 [inline]
wb_workfn+0x3cb/0xef0 fs/fs-writeback.c:2235
process_one_work+0x877/0xdb0 kernel/workqueue.c:2289
worker_thread+0xb14/0x1330 kernel/workqueue.c:2436
kthread+0x266/0x300 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
</TASK>

Allocated by task 11:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x3d/0x60 mm/kasan/common.c:52
____kasan_kmalloc mm/kasan/common.c:371 [inline]
__kasan_kmalloc+0x97/0xb0 mm/kasan/common.c:380
kasan_kmalloc include/linux/kasan.h:211 [inline]
__do_kmalloc_node mm/slab_common.c:955 [inline]
__kmalloc+0xaf/0x1a0 mm/slab_common.c:968
kmalloc include/linux/slab.h:558 [inline]
hfs_find_init+0x8b/0x1e0 fs/hfs/bfind.c:21
hfs_write_inode+0x2e6/0xb40 fs/hfs/inode.c:457
write_inode fs/fs-writeback.c:1440 [inline]
__writeback_single_inode+0x4d6/0x670 fs/fs-writeback.c:1652
writeback_sb_inodes+0xb3b/0x18f0 fs/fs-writeback.c:1878
wb_writeback+0x41f/0x7b0 fs/fs-writeback.c:2052
wb_do_writeback fs/fs-writeback.c:2195 [inline]
wb_workfn+0x3cb/0xef0 fs/fs-writeback.c:2235
process_one_work+0x877/0xdb0 kernel/workqueue.c:2289
worker_thread+0xb14/0x1330 kernel/workqueue.c:2436
kthread+0x266/0x300 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306

The buggy address belongs to the object at ffff88807eb62c00
which belongs to the cache kmalloc-96 of size 96
The buggy address is located 78 bytes inside of
96-byte region [ffff88807eb62c00, ffff88807eb62c60)

The buggy address belongs to the physical page:
page:ffffea0001fad880 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7eb62
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea0000620500 dead000000000004 ffff888012841780
raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY), pid 2973, tgid 2973 (init), ts 13043103035, free_ts 13014326159
prep_new_page mm/page_alloc.c:2539 [inline]
get_page_from_freelist+0x742/0x7c0 mm/page_alloc.c:4291
__alloc_pages+0x259/0x560 mm/page_alloc.c:5558
alloc_slab_page+0x70/0xf0 mm/slub.c:1794
allocate_slab+0x5e/0x4b0 mm/slub.c:1939
new_slab mm/slub.c:1992 [inline]
___slab_alloc+0x782/0xe20 mm/slub.c:3180
__slab_alloc mm/slub.c:3279 [inline]
slab_alloc_node mm/slub.c:3364 [inline]
__kmem_cache_alloc_node+0x252/0x310 mm/slub.c:3437
__do_kmalloc_node mm/slab_common.c:954 [inline]
__kmalloc+0x9e/0x1a0 mm/slab_common.c:968
kmalloc include/linux/slab.h:558 [inline]
kzalloc include/linux/slab.h:689 [inline]
tomoyo_get_name+0x225/0x550 security/tomoyo/memory.c:173
tomoyo_assign_domain+0x369/0x7d0 security/tomoyo/domain.c:569
tomoyo_find_next_domain+0xdfc/0x1d80 security/tomoyo/domain.c:847
tomoyo_bprm_check_security+0xe3/0x130 security/tomoyo/tomoyo.c:101
security_bprm_check+0x50/0xb0 security/security.c:869
search_binary_handler fs/exec.c:1715 [inline]
exec_binprm fs/exec.c:1768 [inline]
bprm_execve+0x817/0x1590 fs/exec.c:1837
do_execveat_common+0x598/0x750 fs/exec.c:1942
do_execve fs/exec.c:2016 [inline]
__do_sys_execve fs/exec.c:2092 [inline]
__se_sys_execve fs/exec.c:2087 [inline]
__x64_sys_execve+0x8e/0xa0 fs/exec.c:2087
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1459 [inline]
free_pcp_prepare+0x80c/0x8f0 mm/page_alloc.c:1509
free_unref_page_prepare mm/page_alloc.c:3387 [inline]
free_unref_page_list+0xb4/0x7b0 mm/page_alloc.c:3529
release_pages+0x232a/0x25c0 mm/swap.c:1055
tlb_batch_pages_flush mm/mmu_gather.c:59 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:256 [inline]
tlb_flush_mmu+0x850/0xa70 mm/mmu_gather.c:263
tlb_finish_mmu+0xcb/0x200 mm/mmu_gather.c:363
exit_mmap+0x275/0x630 mm/mmap.c:3105
__mmput+0x114/0x3b0 kernel/fork.c:1185
exit_mm+0x1f5/0x2d0 kernel/exit.c:516
do_exit+0x5e7/0x2070 kernel/exit.c:807
do_group_exit+0x1fd/0x2b0 kernel/exit.c:950
__do_sys_exit_group kernel/exit.c:961 [inline]
__se_sys_exit_group kernel/exit.c:959 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:959
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

Memory state around the buggy address:
ffff88807eb62b00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
ffff88807eb62b80: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
>ffff88807eb62c00: 00 00 00 00 00 00 00 00 00 06 fc fc fc fc fc fc
^
ffff88807eb62c80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
ffff88807eb62d00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
==================================================================

---
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