hpfs: You really don't want any checks? You are crazy...
hpfs: hpfs_map_sector(): read error
hpfs: code page support is disabled
==================================================================
BUG: KASAN: use-after-free in strcmp+0x6b/0xc0
Read of size 1 at addr ffff88801abcb8a6 by task syz.5.5079/26460

CPU: 0 UID: 0 PID: 26460 Comm: syz.5.5079 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 print_address_description+0x55/0x1e0
 print_report+0x58/0x70
 kasan_report+0x117/0x150
 strcmp+0x6b/0xc0
 hpfs_get_ea+0x134/0xee0
 hpfs_read_inode+0x1a6/0x1050
 hpfs_fill_super+0x123d/0x1fa0
 get_tree_bdev_flags+0x431/0x4f0
 vfs_get_tree+0x92/0x2a0
 do_new_mount+0x341/0xd30
 __se_sys_mount+0x31d/0x420
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa81059e04a
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa8113a7e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fa8113a7ee0 RCX: 00007fa81059e04a
RDX: 000020000000a000 RSI: 0000200000009ec0 RDI: 00007fa8113a7ea0
RBP: 000020000000a000 R08: 00007fa8113a7ee0 R09: 0000000001200041
R10: 0000000001200041 R11: 0000000000000246 R12: 0000200000009ec0
R13: 00007fa8113a7ea0 R14: 0000000000009e15 R15: 0000200000000000
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x2e pfn:0x1abcb
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea00006af288 ffffea00006af588 0000000000000000
raw: 000000000000002e 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Movable, gfp_mask 0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), pid 26451, tgid 26451 (modprobe), ts 979943415121, free_ts 979963487721
 post_alloc_hook+0x231/0x280
 get_page_from_freelist+0x24ba/0x2540
 __alloc_frozen_pages_noprof+0x18d/0x380
 alloc_pages_mpol+0x235/0x490
 folio_alloc_mpol_noprof+0x39/0x160
 vma_alloc_folio_noprof+0xe1/0x1e0
 do_pte_missing+0x520/0x33f0
 handle_mm_fault+0x1bd7/0x3170
 do_user_addr_fault+0xa73/0x1340
 exc_page_fault+0x6a/0xc0
 asm_exc_page_fault+0x26/0x30
page last free pid 26451 tgid 26451 stack trace:
 free_unref_folios+0xcec/0x1480
 folios_put_refs+0x9ff/0xb40
 free_pages_and_swap_cache+0x41d/0x490
 tlb_flush_mmu+0x6d3/0xa30
 tlb_finish_mmu+0xf9/0x230
 exit_mmap+0x498/0x9e0
 __mmput+0x118/0x430
 exit_mm+0x18e/0x250
 do_exit+0x6a2/0x22c0
 do_group_exit+0x21b/0x2d0
 __x64_sys_exit_group+0x3f/0x40
 x64_sys_call+0x221a/0x2240
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88801abcb780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88801abcb800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88801abcb880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                               ^
 ffff88801abcb900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88801abcb980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
