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BUG: KASAN: slab-out-of-bounds in hfs_asc2mac+0x68f/0x710 fs/hfs/trans.c:133
Write of size 1 at addr ffff8880b3c5adce by task syz-executor.4/12917

CPU: 0 PID: 12917 Comm: syz-executor.4 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354
 kasan_report mm/kasan/report.c:412 [inline]
 __asan_report_store1_noabort+0x88/0x90 mm/kasan/report.c:435
 hfs_asc2mac+0x68f/0x710 fs/hfs/trans.c:133
 hfs_cat_build_key+0xbe/0x1a0 fs/hfs/catalog.c:28
 hfs_lookup+0x1c2/0x300 fs/hfs/dir.c:31
 __lookup_hash+0x117/0x180 fs/namei.c:1547
 filename_create+0x186/0x490 fs/namei.c:3639
 user_path_create fs/namei.c:3696 [inline]
 do_mkdirat+0xa0/0x2d0 fs/namei.c:3834
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fe7f26f70f7
Code: 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 02 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe7f0c69f88 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe7f26f70f7
RDX: 00000000000001ff RSI: 00000000200001c0 RDI: 00000000ffffff9c
RBP: 0000000020000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000200001c0 R14: 00007fe7f0c69fe0 R15: 0000000000000000

Allocated by task 12917:
 __do_kmalloc mm/slab.c:3727 [inline]
 __kmalloc+0x15a/0x3c0 mm/slab.c:3736
 kmalloc include/linux/slab.h:520 [inline]
 hfs_find_init+0x91/0x230 fs/hfs/bfind.c:21
 hfs_lookup+0xfe/0x300 fs/hfs/dir.c:28
 __lookup_hash+0x117/0x180 fs/namei.c:1547
 filename_create+0x186/0x490 fs/namei.c:3639
 user_path_create fs/namei.c:3696 [inline]
 do_mkdirat+0xa0/0x2d0 fs/namei.c:3834
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 9:
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xcc/0x210 mm/slab.c:3822
 __rcu_reclaim kernel/rcu/rcu.h:231 [inline]
 rcu_do_batch kernel/rcu/tree.c:2584 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2897 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2864 [inline]
 rcu_process_callbacks+0xa0d/0x18b0 kernel/rcu/tree.c:2881
 __do_softirq+0x265/0x980 kernel/softirq.c:292

The buggy address belongs to the object at ffff8880b3c5ad80
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 78 bytes inside of
 96-byte region [ffff8880b3c5ad80, ffff8880b3c5ade0)
The buggy address belongs to the page:
page:ffffea0002cf1680 count:1 mapcount:0 mapping:ffff88813bff04c0 index:0x0
flags: 0xfff00000000100(slab)
raw: 00fff00000000100 ffffea0002cdda88 ffffea0002d03548 ffff88813bff04c0
raw: 0000000000000000 ffff8880b3c5a000 0000000100000020 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880b3c5ac80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff8880b3c5ad00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff8880b3c5ad80: 00 00 00 00 00 00 00 00 00 06 fc fc fc fc fc fc
                                              ^
 ffff8880b3c5ae00: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
 ffff8880b3c5ae80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
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