==================================================================
BUG: KASAN: slab-out-of-bounds in dns_resolver_preparse+0xca9/0xd70 net/dns_resolver/dns_key.c:127
Read of size 1 at addr ffff888026855be4 by task syz-executor.2/11447

CPU: 1 PID: 11447 Comm: syz-executor.2 Not tainted 6.7.0-rc7-syzkaller-00003-gfbafc3e621c3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xc4/0x620 mm/kasan/report.c:475
 kasan_report+0xda/0x110 mm/kasan/report.c:588
 dns_resolver_preparse+0xca9/0xd70 net/dns_resolver/dns_key.c:127
 __key_create_or_update+0x454/0xe00 security/keys/key.c:842
 key_create_or_update+0x42/0x50 security/keys/key.c:1007
 __do_sys_add_key+0x29c/0x450 security/keys/keyctl.c:134
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7ff81527cce9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff815f3b0c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000f8
RAX: ffffffffffffffda RBX: 00007ff81539bf80 RCX: 00007ff81527cce9
RDX: 0000000020000080 RSI: 0000000020000040 RDI: 00000000200003c0
RBP: 00007ff8152c947a R08: 000000000d3d86fb R09: 0000000000000000
R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007ff81539bf80 R15: 00007fffd0941d68
 </TASK>

Allocated by task 11447:
 kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:383
 kasan_kmalloc include/linux/kasan.h:198 [inline]
 __do_kmalloc_node mm/slab_common.c:1007 [inline]
 __kmalloc_node+0x5c/0x90 mm/slab_common.c:1014
 kmalloc_node include/linux/slab.h:620 [inline]
 kvmalloc_node+0x99/0x1a0 mm/util.c:617
 kvmalloc include/linux/slab.h:738 [inline]
 __do_sys_add_key+0x1f8/0x450 security/keys/keyctl.c:116
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

The buggy address belongs to the object at ffff888026855be0
 which belongs to the cache kmalloc-8 of size 8
The buggy address is located 0 bytes to the right of
 allocated 4-byte region [ffff888026855be0, ffff888026855be4)

The buggy address belongs to the physical page:
page:ffffea00009a1540 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x26855
flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000800 ffff888013041280 dead000000000100 dead000000000122
raw: 0000000000000000 0000000080660066 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 20, tgid 20 (cpuhp/1), ts 10318343254, free_ts 0
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x2d0/0x350 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1544 [inline]
 get_page_from_freelist+0xa25/0x36d0 mm/page_alloc.c:3312
 __alloc_pages+0x22e/0x2420 mm/page_alloc.c:4568
 alloc_pages_mpol+0x258/0x5f0 mm/mempolicy.c:2133
 alloc_slab_page mm/slub.c:1870 [inline]
 allocate_slab mm/slub.c:2017 [inline]
 new_slab+0x283/0x3c0 mm/slub.c:2070
 ___slab_alloc+0x979/0x1500 mm/slub.c:3223
 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3322
 __slab_alloc_node mm/slub.c:3375 [inline]
 slab_alloc_node mm/slub.c:3468 [inline]
 __kmem_cache_alloc_node+0x131/0x310 mm/slub.c:3517
 __do_kmalloc_node mm/slab_common.c:1006 [inline]
 __kmalloc_node_track_caller+0x4a/0x90 mm/slab_common.c:1027
 kstrdup+0x3c/0x70 mm/util.c:62
 kstrdup_const+0x5f/0x70 mm/util.c:85
 __kernfs_new_node+0x9c/0x890 fs/kernfs/dir.c:611
 kernfs_new_node+0x94/0x110 fs/kernfs/dir.c:679
 __kernfs_create_file+0x53/0x340 fs/kernfs/file.c:1025
 sysfs_add_file_mode_ns+0x1ff/0x3b0 fs/sysfs/file.c:307
 sysfs_create_file_ns+0x13e/0x1d0 fs/sysfs/file.c:368
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888026855a80: fc fc fc fc 05 fc fc fc fc 05 fc fc fc fc 05 fc
 ffff888026855b00: fc fc fc 00 fc fc fc fc 07 fc fc fc fc 07 fc fc
>ffff888026855b80: fc fc 00 fc fc fc fc 00 fc fc fc fc 04 fc fc fc
                                                       ^
 ffff888026855c00: fc 04 fc fc fc fc 04 fc fc fc fc 05 fc fc fc fc
 ffff888026855c80: 05 fc fc fc fc 05 fc fc fc fc 00 fc fc fc fc 00
==================================================================