==================================================================
BUG: KASAN: slab-out-of-bounds in scr_memcpyw include/linux/vt_buffer.h:38 [inline]
BUG: KASAN: slab-out-of-bounds in fbcon_prepare_logo+0x94e/0xc60 drivers/video/fbdev/core/fbcon.c:646
Read of size 28 at addr ffff88802273aad0 by task syz.4.579/8851

CPU: 0 UID: 0 PID: 8851 Comm: syz.4.579 Tainted: G     U              syzkaller #0 PREEMPT(full) 
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x156/0x4c9 mm/kasan/report.c:482
 kasan_report+0xdf/0x1e0 mm/kasan/report.c:595
 check_region_inline mm/kasan/generic.c:186 [inline]
 kasan_check_range+0x10f/0x1e0 mm/kasan/generic.c:200
 __asan_memcpy+0x23/0x60 mm/kasan/shadow.c:105
 scr_memcpyw include/linux/vt_buffer.h:38 [inline]
 fbcon_prepare_logo+0x94e/0xc60 drivers/video/fbdev/core/fbcon.c:646
 fbcon_init+0x10a0/0x1820 drivers/video/fbdev/core/fbcon.c:1180
 visual_init+0x320/0x620 drivers/tty/vt/vt.c:1014
 do_bind_con_driver.isra.0+0x636/0x9c0 drivers/tty/vt/vt.c:3954
 vt_bind drivers/tty/vt/vt.c:4110 [inline]
 store_bind+0x609/0x730 drivers/tty/vt/vt.c:4182
 dev_attr_store+0x58/0x80 drivers/base/core.c:2437
 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:142
 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:352
 iter_file_splice_write+0x830/0x10a0 fs/splice.c:736
 do_splice_from fs/splice.c:936 [inline]
 direct_splice_actor+0x192/0x6c0 fs/splice.c:1159
 splice_direct_to_actor+0x345/0xa30 fs/splice.c:1103
 do_splice_direct_actor fs/splice.c:1202 [inline]
 do_splice_direct+0x174/0x240 fs/splice.c:1228
 do_sendfile+0xadc/0xe20 fs/read_write.c:1372
 __do_sys_sendfile64 fs/read_write.c:1433 [inline]
 __se_sys_sendfile64 fs/read_write.c:1419 [inline]
 __x64_sys_sendfile64+0x1d8/0x220 fs/read_write.c:1419
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0472d9c799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0470fb4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f0473016180 RCX: 00007f0472d9c799
RDX: 0000000000000000 RSI: 000000000000000d RDI: 0000000000000006
RBP: 00007f0472e32bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0473016218 R14: 00007f0473016180 R15: 00007ffc0d2a5a68
 </TASK>

Allocated by task 7856:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5238 [inline]
 __kmalloc_node_track_caller_noprof+0x304/0x850 mm/slub.c:5346
 kmemdup_noprof+0x29/0x60 mm/util.c:138
 kmemdup_noprof include/linux/fortify-string.h:763 [inline]
 neigh_parms_alloc+0x85/0x5e0 net/core/neighbour.c:1772
 ipv6_add_dev+0x3f7/0x1520 net/ipv6/addrconf.c:402
 addrconf_notify+0x563/0x19c0 net/ipv6/addrconf.c:3654
 notifier_call_chain+0x99/0x420 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2249
 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
 call_netdevice_notifiers net/core/dev.c:2301 [inline]
 register_netdevice+0x16e6/0x2210 net/core/dev.c:11460
 bond_newlink+0x6a/0x100 drivers/net/bonding/bond_netlink.c:601
 rtnl_newlink_create net/core/rtnetlink.c:3840 [inline]
 __rtnl_newlink net/core/rtnetlink.c:3957 [inline]
 rtnl_newlink+0x1494/0x2380 net/core/rtnetlink.c:4072
 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6958
 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 __sys_sendto+0x4aa/0x520 net/socket.c:2206
 __do_sys_sendto net/socket.c:2213 [inline]
 __se_sys_sendto net/socket.c:2209 [inline]
 __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2209
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 15:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2692 [inline]
 slab_free mm/slub.c:6143 [inline]
 kfree+0x1f6/0x6b0 mm/slub.c:6461
 neigh_parms_put net/core/neighbour.c:910 [inline]
 neigh_rcu_free_parms+0x61/0xa0 net/core/neighbour.c:1804
 rcu_do_batch kernel/rcu/tree.c:2617 [inline]
 rcu_core+0x5a2/0x10d0 kernel/rcu/tree.c:2869
 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
 run_ksoftirqd kernel/softirq.c:1063 [inline]
 run_ksoftirqd+0x38/0x60 kernel/softirq.c:1055
 smpboot_thread_fn+0x3d3/0xaa0 kernel/smpboot.c:160
 kthread+0x370/0x450 kernel/kthread.c:467
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Last potentially related work creation:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:556
 __call_rcu_common.constprop.0+0xa5/0x9b0 kernel/rcu/tree.c:3131
 neigh_parms_release net/core/neighbour.c:1818 [inline]
 neigh_parms_release+0x1de/0x260 net/core/neighbour.c:1807
 addrconf_ifdown.isra.0+0x1563/0x1b70 net/ipv6/addrconf.c:4011
 addrconf_notify+0x458/0x19c0 net/ipv6/addrconf.c:3780
 notifier_call_chain+0x99/0x420 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2249
 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
 call_netdevice_notifiers net/core/dev.c:2301 [inline]
 unregister_netdevice_many_notify+0x1208/0x2580 net/core/dev.c:12412
 rtnl_delete_link net/core/rtnetlink.c:3528 [inline]
 rtnl_dellink+0x472/0xb40 net/core/rtnetlink.c:3570
 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6958
 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 ____sys_sendmsg+0xa54/0xc30 net/socket.c:2592
 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2646
 __sys_sendmmsg+0x205/0x430 net/socket.c:2735
 __do_sys_sendmmsg net/socket.c:2762 [inline]
 __se_sys_sendmmsg net/socket.c:2759 [inline]
 __x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2759
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88802273aa00
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 16 bytes to the right of
 allocated 192-byte region [ffff88802273aa00, ffff88802273aac0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2273a
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88813fe3c3c0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800100010 00000000f5000000 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 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 7494, tgid 7490 (syz.0.326), ts 181036602021, free_ts 177627267496
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3269 [inline]
 allocate_slab mm/slub.c:3458 [inline]
 new_slab+0xa6/0x6d0 mm/slub.c:3516
 refill_objects+0x26b/0x400 mm/slub.c:7153
 refill_sheaf mm/slub.c:2818 [inline]
 alloc_full_sheaf mm/slub.c:2839 [inline]
 __pcs_replace_empty_main+0x19f/0x600 mm/slub.c:4602
 alloc_from_pcs mm/slub.c:4695 [inline]
 slab_alloc_node mm/slub.c:4829 [inline]
 __kmalloc_cache_noprof+0x493/0x6f0 mm/slub.c:5353
 kmalloc_noprof include/linux/slab.h:950 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 kset_create lib/kobject.c:965 [inline]
 kset_create_and_add+0x4d/0x190 lib/kobject.c:1008
 register_queue_kobjects net/core/net-sysfs.c:2106 [inline]
 netdev_register_kobject+0x1ef/0x3d0 net/core/net-sysfs.c:2362
 register_netdevice+0x12e0/0x2210 net/core/dev.c:11422
 register_netdev+0x34/0x50 net/core/dev.c:11538
 ip6_tnl_init_net+0x2ff/0x480 net/ipv6/ip6_tunnel.c:2334
 ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137
 setup_net+0x118/0x3a0 net/core/net_namespace.c:446
 copy_net_ns+0x46f/0x7c0 net/core/net_namespace.c:581
 create_new_namespaces+0x3ea/0xac0 kernel/nsproxy.c:130
page last free pid 5818 tgid 5818 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978
 pcpu_free_pages.isra.0+0x13c/0x1c0 mm/percpu-vm.c:65
 pcpu_reclaim_populated mm/percpu.c:2158 [inline]
 pcpu_balance_workfn+0x24e/0xdd0 mm/percpu.c:2214
 process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275
 process_scheduled_works kernel/workqueue.c:3358 [inline]
 worker_thread+0x5da/0xe40 kernel/workqueue.c:3439
 kthread+0x370/0x450 kernel/kthread.c:467
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff88802273a980: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff88802273aa00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88802273aa80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                                                 ^
 ffff88802273ab00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88802273ab80: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
==================================================================