loop6: detected capacity change from 0 to 128
hpfs: filesystem error: invalid number of hotfixes: 2066844986, used: 2066844985; already mounted read-only
hpfs: filesystem error: improperly stopped
hpfs: filesystem error: warning: spare dnodes used, try chkdsk
hpfs: You really don't want any checks? You are crazy...
hpfs: hpfs_map_sector(): read error
hpfs: cod[  172.024744][ T7276] hpfs: code page support is disabled
==================================================================
BUG: KASAN: slab-out-of-bounds in strcmp+0x6b/0xc0 lib/string.c:283
Read of size 1 at addr ffff8880332a3003 by task syz.6.187/7276

CPU: 0 UID: 0 PID: 7276 Comm: syz.6.187 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xba/0x230 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 strcmp+0x6b/0xc0 lib/string.c:283
 hpfs_get_ea+0x134/0xee0 fs/hpfs/ea.c:139
 hpfs_read_inode+0x1a6/0x1050 fs/hpfs/inode.c:63
 hpfs_fill_super+0x123d/0x1fa0 fs/hpfs/super.c:651
 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694
 vfs_get_tree+0x92/0x2a0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3763 [inline]
 do_new_mount+0x341/0xd30 fs/namespace.c:3839
 do_mount fs/namespace.c:4172 [inline]
 __do_sys_mount fs/namespace.c:4361 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4338
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa78aacda0a
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:00007fa788d25e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fa788d25ee0 RCX: 00007fa78aacda0a
RDX: 0000200000000100 RSI: 0000200000000040 RDI: 00007fa788d25ea0
RBP: 0000200000000100 R08: 00007fa788d25ee0 R09: 0000000003200041
R10: 0000000003200041 R11: 0000000000000246 R12: 0000200000000040
R13: 00007fa788d25ea0 R14: 0000000000009e15 R15: 00002000000000c0
 </TASK>

Allocated by task 1:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x3a6/0x690 mm/slub.c:5383
 kmalloc_noprof include/linux/slab.h:950 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 snmp6_alloc_dev net/ipv6/addrconf.c:361 [inline]
 ipv6_add_dev+0x6e8/0x1400 net/ipv6/addrconf.c:412
 addrconf_notify+0x771/0x1050 net/ipv6/addrconf.c:3654
 notifier_call_chain+0x1be/0x400 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
 call_netdevice_notifiers net/core/dev.c:2301 [inline]
 register_netdevice+0x1751/0x1d10 net/core/dev.c:11462
 register_netdev+0x40/0x60 net/core/dev.c:11540
 ip6gre_init_net+0x291/0x3c0 net/ipv6/ip6_gre.c:1608
 ops_init+0x35c/0x5c0 net/core/net_namespace.c:137
 __register_pernet_operations net/core/net_namespace.c:1320 [inline]
 register_pernet_operations+0x343/0x830 net/core/net_namespace.c:1397
 register_pernet_device+0x2a/0x80 net/core/net_namespace.c:1484
 ip6gre_init+0x1d/0xd0 net/ipv6/ip6_gre.c:2334
 do_one_initcall+0x250/0x8d0 init/main.c:1382
 do_initcall_level+0x104/0x190 init/main.c:1444
 do_initcalls+0x59/0xa0 init/main.c:1460
 kernel_init_freeable+0x2a6/0x3e0 init/main.c:1692
 kernel_init+0x1d/0x1d0 init/main.c:1582
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff8880332a2000
 which belongs to the cache kmalloc-cg-4k of size 4096
The buggy address is located 3 bytes to the right of
 allocated 4096-byte region [ffff8880332a2000, ffff8880332a3000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x332a0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x80000000000040(head|node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000040 ffff88813fe35500 dead000000000122 0000000000000000
raw: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000
head: 0080000000000040 ffff88813fe35500 dead000000000122 0000000000000000
head: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000
head: 0080000000000003 ffffea0000cca801 00000000ffffffff 00000000ffffffff
head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 15479091551, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x28bb/0x2950 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3296 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3485
 new_slab mm/slub.c:3543 [inline]
 refill_objects+0x334/0x3c0 mm/slub.c:7178
 __pcs_replace_empty_main+0x371/0x5c0 mm/slub.c:-1
 alloc_from_pcs mm/slub.c:4720 [inline]
 slab_alloc_node mm/slub.c:4854 [inline]
 __do_kmalloc_node mm/slub.c:5262 [inline]
 __kmalloc_noprof+0x530/0x7b0 mm/slub.c:5275
 kmalloc_noprof include/linux/slab.h:954 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 __register_sysctl_table+0x72/0x1340 fs/proc/proc_sysctl.c:1379
 __addrconf_sysctl_register+0x331/0x4d0 net/ipv6/addrconf.c:7327
 addrconf_sysctl_register+0x168/0x1c0 net/ipv6/addrconf.c:7375
 ipv6_add_dev+0xd64/0x1400 net/ipv6/addrconf.c:459
 addrconf_notify+0x771/0x1050 net/ipv6/addrconf.c:3654
 notifier_call_chain+0x1be/0x400 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
 call_netdevice_notifiers net/core/dev.c:2301 [inline]
 register_netdevice+0x1751/0x1d10 net/core/dev.c:11462
 register_netdev+0x40/0x60 net/core/dev.c:11540
 ip6_tnl_init_net+0x259/0x3b0 net/ipv6/ip6_tunnel.c:2334
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8880332a2f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880332a2f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880332a3000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff8880332a3080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880332a3100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================