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+0x6f/0xc0
Read of size 1 at addr ffff8881bedd68a6 by task syz.5.112/6678

CPU: 1 UID: 0 PID: 6678 Comm: syz.5.112 Not tainted syzkaller #0 PREEMPT(full) 
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_report+0xca/0x240
 kasan_report+0x118/0x150
 strcmp+0x6f/0xc0
 hpfs_get_ea+0x114/0xdb0
 hpfs_read_inode+0x19d/0x1010
 hpfs_fill_super+0x129d/0x2040
 get_tree_bdev_flags+0x40e/0x4d0
 vfs_get_tree+0x92/0x2a0
 do_new_mount+0x302/0xa10
 __se_sys_mount+0x313/0x410
 do_syscall_64+0xec/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd5b1f90f6a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd5b2f0fe68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fd5b2f0fef0 RCX: 00007fd5b1f90f6a
RDX: 0000200000000000 RSI: 0000200000009ec0 RDI: 00007fd5b2f0feb0
RBP: 0000200000000000 R08: 00007fd5b2f0fef0 R09: 0000000003200041
R10: 0000000003200041 R11: 0000000000000246 R12: 0000200000009ec0
R13: 00007fd5b2f0feb0 R14: 0000000000009e2f R15: 0000200000000080
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x562cfd46d pfn:0x1bedd6
flags: 0x57ff00000000000(node=1|zone=2|lastcpupid=0x7ff)
raw: 057ff00000000000 ffffea0006f8ce48 ffffea0006fb75c8 0000000000000000
raw: 0000000562cfd46d 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 0x140dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO|__GFP_COMP), pid 6665, tgid 6665 (dhcpcd-run-hook), ts 93475528027, free_ts 93601746491
 post_alloc_hook+0x234/0x290
 get_page_from_freelist+0x24e0/0x2580
 __alloc_frozen_pages_noprof+0x181/0x370
 alloc_pages_mpol+0x232/0x4a0
 vma_alloc_folio_noprof+0xe4/0x200
 folio_prealloc+0x30/0x180
 do_pte_missing+0x14e8/0x3330
 handle_mm_fault+0x1b26/0x32b0
 do_user_addr_fault+0xa7c/0x1380
 exc_page_fault+0x71/0xd0
 asm_exc_page_fault+0x26/0x30
page last free pid 6665 tgid 6665 stack trace:
 free_unref_folios+0xdb3/0x14f0
 folios_put_refs+0x584/0x670
 free_pages_and_swap_cache+0x4be/0x520
 tlb_flush_mmu+0x3a0/0x680
 tlb_finish_mmu+0xc3/0x1d0
 exit_mmap+0x439/0xb10
 __mmput+0x118/0x430
 exit_mm+0x169/0x230
 do_exit+0x627/0x22f0
 do_group_exit+0x21c/0x2d0
 __x64_sys_exit_group+0x3f/0x40
 __pfx_syscall_get_nr+0x0/0x10
 do_syscall_64+0xec/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff8881bedd6780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881bedd6800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8881bedd6880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                               ^
 ffff8881bedd6900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881bedd6980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
