hpfs: hpfs_map_sector(): read error
hpfs: code page support is disabled
==================================================================
BUG: KASAN: use-after-free in strcmp+0x6b/0xb0 lib/string.c:361
Read of size 1 at addr ffff8880518368a6 by task syz.4.56/4695

CPU: 1 PID: 4695 Comm: syz.4.56 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:316 [inline]
 print_report+0xa8/0x210 mm/kasan/report.c:420
 kasan_report+0x10b/0x140 mm/kasan/report.c:524
 strcmp+0x6b/0xb0 lib/string.c:361
 hpfs_get_ea+0x111/0xc80 fs/hpfs/ea.c:139
 hpfs_read_inode+0x19a/0x1000 fs/hpfs/inode.c:63
 hpfs_fill_super+0x12d1/0x1eb0 fs/hpfs/super.c:712
 mount_bdev+0x287/0x3c0 fs/super.c:1443
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:632
 vfs_get_tree+0x88/0x270 fs/super.c:1573
 do_new_mount+0x24a/0xa40 fs/namespace.c:3069
 do_mount fs/namespace.c:3412 [inline]
 __do_sys_mount fs/namespace.c:3620 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3597
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fe1fff9038a
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:00007fe200d68e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fe200d68ef0 RCX: 00007fe1fff9038a
RDX: 000020000000a000 RSI: 0000200000000000 RDI: 00007fe200d68eb0
RBP: 000020000000a000 R08: 00007fe200d68ef0 R09: 0000000003200041
R10: 0000000003200041 R11: 0000000000000246 R12: 0000200000000000
R13: 00007fe200d68eb0 R14: 0000000000009e15 R15: 0000200000000040
 </TASK>

The buggy address belongs to the physical page:
page:ffffea0001460d80 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x51836
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0001460e48 ffffea0001460f88 0000000000000000
raw: 0000000000000001 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 4702, tgid 4702 (dhcpcd), ts 115100025758, free_ts 115241182410
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532
 prep_new_page mm/page_alloc.c:2539 [inline]
 get_page_from_freelist+0x1a26/0x1ac0 mm/page_alloc.c:4328
 __alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5614
 __folio_alloc+0xe/0x30 mm/page_alloc.c:5646
 vma_alloc_folio+0x4a3/0x900 mm/mempolicy.c:2243
 alloc_page_vma include/linux/gfp.h:284 [inline]
 wp_page_copy+0x26c/0x1640 mm/memory.c:3153
 handle_pte_fault mm/memory.c:5049 [inline]
 __handle_mm_fault mm/memory.c:5173 [inline]
 handle_mm_fault+0x1ca6/0x3e70 mm/memory.c:5294
 do_user_addr_fault+0x51f/0xb10 arch/x86/mm/fault.c:1340
 handle_page_fault arch/x86/mm/fault.c:1431 [inline]
 exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1487
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1459 [inline]
 free_pcp_prepare mm/page_alloc.c:1509 [inline]
 free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384
 free_unref_page_list+0xbb/0x8e0 mm/page_alloc.c:3525
 release_pages+0x1f92/0x2200 mm/swap.c:1035
 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:254 [inline]
 tlb_flush_mmu+0xff/0x210 mm/mmu_gather.c:261
 tlb_finish_mmu+0xbd/0x1c0 mm/mmu_gather.c:361
 exit_mmap+0x343/0x8e0 mm/mmap.c:3262
 __mmput+0x118/0x3c0 kernel/fork.c:1200
 exit_mm+0x1e6/0x2c0 kernel/exit.c:565
 do_exit+0x8c1/0x2400 kernel/exit.c:867
 do_group_exit+0x217/0x2d0 kernel/exit.c:1022
 __do_sys_exit_group kernel/exit.c:1033 [inline]
 __se_sys_exit_group kernel/exit.c:1031 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1031
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Memory state around the buggy address:
 ffff888051836780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888051836800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888051836880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                               ^
 ffff888051836900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888051836980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================