[syzbot] KASAN: slab-out-of-bounds Write in udf_find_entry

[syzbot] KASAN: slab-out-of-bounds Write in udf_find_entry

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    a6afa4199d3d Merge tag 'mailbox-v6.1' of git://git.linaro...
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1725efbc880000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d19f5d16783f901
dashboard link: https://syzkaller.appspot.com/bug?extid=69c9fdccc6dd08961d34
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=16f5d358880000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14ccc11c880000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/12e24d042ff9/disk-a6afa419.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4862ae4e2edf/vmlinux-a6afa419.xz
mounted in repro #1: https://storage.googleapis.com/syzbot-assets/575958c7b620/mount_0.gz
mounted in repro #2: https://storage.googleapis.com/syzbot-assets/9e49c32cc0ea/mount_7.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+69c9fdccc6dd08961d34@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-out-of-bounds in udf_find_entry+0x8a5/0x14f0 fs/udf/namei.c:253
Write of size 165 at addr ffff888028a7925a by task syz-executor237/3608

CPU: 1 PID: 3608 Comm: syz-executor237 Not tainted 6.0.0-syzkaller-09039-ga6afa4199d3d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106
 print_address_description+0x65/0x4b0 mm/kasan/report.c:317
 print_report+0x108/0x1f0 mm/kasan/report.c:433
 kasan_report+0xc3/0xf0 mm/kasan/report.c:495
 kasan_check_range+0x2a7/0x2e0 mm/kasan/generic.c:189
 memcpy+0x3c/0x60 mm/kasan/shadow.c:66
 udf_find_entry+0x8a5/0x14f0 fs/udf/namei.c:253
 udf_lookup+0xef/0x340 fs/udf/namei.c:309
 __lookup_hash+0x115/0x240 fs/namei.c:1601
 do_unlinkat+0x26b/0x940 fs/namei.c:4281
 do_coredump+0x20fb/0x2970 fs/coredump.c:667
 get_signal+0x1417/0x1770 kernel/signal.c:2843
 arch_do_signal_or_restart+0x7b/0x730 arch/x86/kernel/signal.c:869
 exit_to_user_mode_loop+0x74/0x150 kernel/entry/common.c:166
 exit_to_user_mode_prepare+0xb2/0x140 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:294
 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f30538fb8d6
Code: b8 ff ff ff ff eb b9 e8 68 3b 04 00 0f 1f 84 00 00 00 00 00 49 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 11 b8 12 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 5a c3 90 48 83 ec 28 48 89 54 24 10 48 89 74
RSP: 002b:00007ffc4fc1dd88 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffe5 RBX: 0000000000000006 RCX: 00007f30538fb8d6
RDX: 0000000000000027 RSI: 0000020006000001 RDI: 0000000000000006
RBP: 00007ffc4fc1dda0 R08: 00007ffc4fc1dc20 R09: 0000555555693380
R10: 6608000000000014 R11: 0000000000000246 R12: 0000000000000028
R13: 0000000000000006 R14: 000000000000001c R15: 00000000200004a0
 </TASK>

Allocated by task 3608:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:437 [inline]
 ____kasan_kmalloc+0xcd/0x100 mm/kasan/common.c:516
 kasan_kmalloc include/linux/kasan.h:234 [inline]
 kmem_cache_alloc_trace+0x97/0x310 mm/slub.c:3289
 kmalloc include/linux/slab.h:600 [inline]
 udf_find_entry+0x7b6/0x14f0 fs/udf/namei.c:243
 udf_lookup+0xef/0x340 fs/udf/namei.c:309
 __lookup_hash+0x115/0x240 fs/namei.c:1601
 do_unlinkat+0x26b/0x940 fs/namei.c:4281
 do_coredump+0x20fb/0x2970 fs/coredump.c:667
 get_signal+0x1417/0x1770 kernel/signal.c:2843
 arch_do_signal_or_restart+0x7b/0x730 arch/x86/kernel/signal.c:869
 exit_to_user_mode_loop+0x74/0x150 kernel/entry/common.c:166
 exit_to_user_mode_prepare+0xb2/0x140 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:294
 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

The buggy address belongs to the object at ffff888028a79200
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 90 bytes inside of
 256-byte region [ffff888028a79200, ffff888028a79300)

The buggy address belongs to the physical page:
page:ffffea0000a29e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x28a78
head:ffffea0000a29e00 order:1 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea0000a29d80 dead000000000002 ffff888012041b40
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 2, tgid 2 (kthreadd), ts 11303152503, free_ts 0
 prep_new_page mm/page_alloc.c:2532 [inline]
 get_page_from_freelist+0x742/0x7c0 mm/page_alloc.c:4283
 __alloc_pages+0x259/0x560 mm/page_alloc.c:5549
 alloc_slab_page+0x70/0xf0 mm/slub.c:1829
 allocate_slab+0x5e/0x520 mm/slub.c:1974
 new_slab mm/slub.c:2034 [inline]
 ___slab_alloc+0x3ee/0xc40 mm/slub.c:3036
 __slab_alloc mm/slub.c:3123 [inline]
 slab_alloc_node mm/slub.c:3214 [inline]
 slab_alloc mm/slub.c:3256 [inline]
 kmem_cache_alloc_trace+0x25f/0x310 mm/slub.c:3287
 kmalloc include/linux/slab.h:600 [inline]
 kzalloc include/linux/slab.h:733 [inline]
 set_kthread_struct+0xb1/0x1f0 kernel/kthread.c:117
 copy_process+0x134d/0x3fa0 kernel/fork.c:2181
 kernel_clone+0x21f/0x790 kernel/fork.c:2671
 kernel_thread+0x150/0x1d0 kernel/fork.c:2724
 create_kthread kernel/kthread.c:399 [inline]
 kthreadd+0x57c/0x750 kernel/kthread.c:745
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888028a79180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888028a79200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888028a79280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 06
                                                                ^
 ffff888028a79300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888028a79380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


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