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 ffff88801164f001 by task syz.0.8/5960

CPU: 1 UID: 0 PID: 5960 Comm: syz.0.8 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+0x189/0x250
 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+0x92/0x2b0
 do_new_mount+0x302/0x9e0
 __se_sys_mount+0x313/0x410
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa7a85903ca
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:00007fa7a937be68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fa7a937bef0 RCX: 00007fa7a85903ca
RDX: 000020000000a000 RSI: 0000200000009ec0 RDI: 00007fa7a937beb0
RBP: 000020000000a000 R08: 00007fa7a937bef0 R09: 0000000003a00041
R10: 0000000003a00041 R11: 0000000000000246 R12: 0000200000009ec0
R13: 00007fa7a937beb0 R14: 0000000000009e2e R15: 0000200000000080
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x53 pfn:0x1164f
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0000459588 ffffea0000459308 0000000000000000
raw: 0000000000000053 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 5961, tgid 5961 (modprobe), ts 59050858761, free_ts 59058375600
 post_alloc_hook+0x240/0x2a0
 get_page_from_freelist+0x2365/0x2440
 __alloc_frozen_pages_noprof+0x181/0x370
 alloc_pages_mpol+0x232/0x4a0
 vma_alloc_folio_noprof+0xe4/0x200
 folio_prealloc+0x30/0x180
 __handle_mm_fault+0x16fd/0x5400
 handle_mm_fault+0x40a/0x8e0
 do_user_addr_fault+0xa7c/0x1380
 exc_page_fault+0x82/0x100
 asm_exc_page_fault+0x26/0x30
page last free pid 5961 tgid 5961 stack trace:
 free_unref_folios+0xdb3/0x14f0
 folios_put_refs+0x584/0x670
 free_pages_and_swap_cache+0x277/0x520
 tlb_flush_mmu+0x3a0/0x680
 tlb_finish_mmu+0xc3/0x1d0
 exit_mmap+0x444/0xb40
 __mmput+0x118/0x430
 exit_mm+0x1da/0x2c0
 do_exit+0x648/0x2300
 do_group_exit+0x21c/0x2d0
 __x64_sys_exit_group+0x3f/0x40
 x64_sys_call+0x21f7/0x2200
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88801164ef00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88801164ef80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88801164f000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff88801164f080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88801164f100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
