================================================================== 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 256 at addr ffff888076746380 by task syz.2.4121/26406 CPU: 1 UID: 0 PID: 26406 Comm: syz.2.4121 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: __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 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x6ac/0x1070 fs/read_write.c:688 ksys_write+0x12a/0x250 fs/read_write.c:740 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: 0033:0x7f6ea2b9c799 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:00007f6ea3af8028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f6ea2e16180 RCX: 00007f6ea2b9c799 RDX: 0000000000000084 RSI: 0000200000000040 RDI: 0000000000000003 RBP: 00007f6ea2c32c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6ea2e16218 R14: 00007f6ea2e16180 R15: 00007ffe1004dc18 Allocated by task 26155: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4538 [inline] slab_alloc_node mm/slub.c:4866 [inline] kmem_cache_alloc_node_noprof+0x25a/0x6f0 mm/slub.c:4918 kmalloc_reserve+0x148/0x350 net/core/skbuff.c:613 __alloc_skb+0x185/0x710 net/core/skbuff.c:713 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_uevent_skb+0x7d/0x210 lib/kobject_uevent.c:289 uevent_net_broadcast_tagged lib/kobject_uevent.c:352 [inline] kobject_uevent_net_broadcast lib/kobject_uevent.c:413 [inline] kobject_uevent_env+0x122c/0x18b0 lib/kobject_uevent.c:608 netdev_queue_add_kobject net/core/net-sysfs.c:2013 [inline] netdev_queue_update_kobjects+0x1a7/0x6f0 net/core/net-sysfs.c:2056 register_queue_kobjects net/core/net-sysfs.c:2119 [inline] netdev_register_kobject+0x2b3/0x3d0 net/core/net-sysfs.c:2362 register_netdevice+0x12e0/0x2210 net/core/dev.c:11424 __ip_tunnel_create+0x52b/0x670 net/ipv4/ip_tunnel.c:268 ip_tunnel_init_net+0x230/0x780 net/ipv4/ip_tunnel.c:1147 vti_init_net+0x2e/0x140 net/ipv4/ip_vti.c:517 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 unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x473/0xad0 kernel/fork.c:3174 __do_sys_unshare kernel/fork.c:3245 [inline] __se_sys_unshare kernel/fork.c:3243 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3243 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 26155: 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:2685 [inline] slab_free mm/slub.c:6165 [inline] kmem_cache_free+0x124/0x6a0 mm/slub.c:6295 skb_kfree_head net/core/skbuff.c:1087 [inline] skb_kfree_head net/core/skbuff.c:1084 [inline] skb_free_head+0x1c6/0x220 net/core/skbuff.c:1101 skb_release_data+0x79b/0x9d0 net/core/skbuff.c:1128 skb_release_all net/core/skbuff.c:1203 [inline] __kfree_skb net/core/skbuff.c:1217 [inline] consume_skb net/core/skbuff.c:1450 [inline] consume_skb+0xc4/0x110 net/core/skbuff.c:1444 netlink_broadcast_filtered+0x3cc/0xf50 net/netlink/af_netlink.c:1535 netlink_broadcast+0x39/0x50 net/netlink/af_netlink.c:1557 uevent_net_broadcast_tagged lib/kobject_uevent.c:373 [inline] kobject_uevent_net_broadcast lib/kobject_uevent.c:413 [inline] kobject_uevent_env+0x1313/0x18b0 lib/kobject_uevent.c:608 netdev_queue_add_kobject net/core/net-sysfs.c:2013 [inline] netdev_queue_update_kobjects+0x1a7/0x6f0 net/core/net-sysfs.c:2056 register_queue_kobjects net/core/net-sysfs.c:2119 [inline] netdev_register_kobject+0x2b3/0x3d0 net/core/net-sysfs.c:2362 register_netdevice+0x12e0/0x2210 net/core/dev.c:11424 __ip_tunnel_create+0x52b/0x670 net/ipv4/ip_tunnel.c:268 ip_tunnel_init_net+0x230/0x780 net/ipv4/ip_tunnel.c:1147 vti_init_net+0x2e/0x140 net/ipv4/ip_vti.c:517 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 unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x473/0xad0 kernel/fork.c:3174 __do_sys_unshare kernel/fork.c:3245 [inline] __se_sys_unshare kernel/fork.c:3243 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3243 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 ffff888076746080 which belongs to the cache skbuff_small_head of size 704 The buggy address is located 64 bytes to the right of allocated 704-byte region [ffff888076746080, ffff888076746340) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x76744 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801eab8dc0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800130013 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801eab8dc0 dead000000000100 dead000000000122 head: 0000000000000000 0000000800130013 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea0001d9d101 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 13211, tgid 13210 (syz.0.1265), ts 660644397942, free_ts 656149329790 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:3292 [inline] allocate_slab mm/slub.c:3481 [inline] new_slab+0xa6/0x6b0 mm/slub.c:3539 refill_objects+0x26b/0x400 mm/slub.c:7175 refill_sheaf mm/slub.c:2812 [inline] __pcs_replace_empty_main+0x1ab/0x660 mm/slub.c:4615 alloc_from_pcs mm/slub.c:4717 [inline] slab_alloc_node mm/slub.c:4851 [inline] kmem_cache_alloc_node_noprof+0x569/0x6f0 mm/slub.c:4918 kmalloc_reserve+0x148/0x350 net/core/skbuff.c:613 __alloc_skb+0x185/0x710 net/core/skbuff.c:713 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0xe0/0x810 net/core/skbuff.c:6763 sock_alloc_send_pskb+0x801/0x980 net/core/sock.c:2995 sock_alloc_send_skb include/net/sock.h:1894 [inline] __ip_append_data+0x227d/0x4690 net/ipv4/ip_output.c:1127 ip_append_data net/ipv4/ip_output.c:1378 [inline] ip_append_data+0x10f/0x1a0 net/ipv4/ip_output.c:1357 icmp_push_reply+0xab/0x450 net/ipv4/icmp.c:388 __icmp_send+0x1184/0x2c30 net/ipv4/icmp.c:1000 icmp_send include/net/icmp.h:43 [inline] ip_protocol_deliver_rcu+0x421/0x4d0 net/ipv4/ip_input.c:218 page last free pid 13149 tgid 13148 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 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4538 [inline] slab_alloc_node mm/slub.c:4866 [inline] __kmalloc_cache_noprof+0x243/0x6f0 mm/slub.c:5375 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:11424 register_netdev+0x34/0x50 net/core/dev.c:11540 sit_init_net+0x2c0/0x5f0 net/ipv6/sit.c:1859 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 unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x473/0xad0 kernel/fork.c:3174 Memory state around the buggy address: ffff888076746280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888076746300: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff888076746380: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ^ ffff888076746400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888076746480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================