==================================================================
BUG: KASAN: slab-use-after-free in scr_memcpyw include/linux/vt_buffer.h:38 [inline]
BUG: KASAN: slab-use-after-free in fbcon_prepare_logo+0xa03/0xc70 drivers/video/fbdev/core/fbcon.c:646
Read of size 256 at addr ffff888038e163c0 by task syz.2.1668/15002

CPU: 0 UID: 0 PID: 15002 Comm: syz.2.1668 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xcd/0x630 mm/kasan/report.c:482
 kasan_report+0xe0/0x110 mm/kasan/report.c:595
 check_region_inline mm/kasan/generic.c:194 [inline]
 kasan_check_range+0x100/0x1b0 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+0xa03/0xc70 drivers/video/fbdev/core/fbcon.c:646
 fbcon_init+0xda0/0x1930 drivers/video/fbdev/core/fbcon.c:1179
 visual_init+0x320/0x620 drivers/tty/vt/vt.c:1020
 do_bind_con_driver.isra.0+0x57a/0xbf0 drivers/tty/vt/vt.c:3960
 vt_bind drivers/tty/vt/vt.c:4116 [inline]
 store_bind+0x61d/0x760 drivers/tty/vt/vt.c:4188
 dev_attr_store+0x58/0x80 drivers/base/core.c:2437
 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:142
 kernfs_fop_write_iter+0x3af/0x570 fs/kernfs/file.c:352
 iter_file_splice_write+0xa24/0x12b0 fs/splice.c:738
 do_splice_from fs/splice.c:938 [inline]
 direct_splice_actor+0x192/0x6c0 fs/splice.c:1161
 splice_direct_to_actor+0x345/0xa30 fs/splice.c:1105
 do_splice_direct_actor fs/splice.c:1204 [inline]
 do_splice_direct+0x174/0x240 fs/splice.c:1230
 do_sendfile+0xb06/0xe50 fs/read_write.c:1370
 __do_sys_sendfile64 fs/read_write.c:1431 [inline]
 __se_sys_sendfile64 fs/read_write.c:1417 [inline]
 __x64_sys_sendfile64+0x1d8/0x220 fs/read_write.c:1417
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6583d8f7c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6584b5f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f6583fe5fa0 RCX: 00007f6583d8f7c9
RDX: 0000000000000000 RSI: 000000000000000a RDI: 0000000000000004
RBP: 00007f6583e13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6583fe6038 R14: 00007f6583fe5fa0 R15: 00007ffddebf9b98
 </TASK>

Allocated by task 14883:
 kasan_save_stack+0x33/0x60 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:4953 [inline]
 slab_alloc_node mm/slub.c:5263 [inline]
 kmem_cache_alloc_noprof+0x25e/0x770 mm/slub.c:5270
 skb_clone+0x190/0x3f0 net/core/skbuff.c:2087
 dev_queue_xmit_nit+0x25b/0xac0 net/core/dev.c:2555
 xmit_one net/core/dev.c:3849 [inline]
 dev_hard_start_xmit+0x56b/0x6e0 net/core/dev.c:3869
 sch_direct_xmit+0x1b2/0xcd0 net/sched/sch_generic.c:347
 __dev_xmit_skb net/core/dev.c:4169 [inline]
 __dev_queue_xmit+0x14a6/0x46b0 net/core/dev.c:4785
 dev_queue_xmit include/linux/netdevice.h:3381 [inline]
 neigh_hh_output include/net/neighbour.h:540 [inline]
 neigh_output include/net/neighbour.h:554 [inline]
 ip_finish_output2+0xc38/0x21a0 net/ipv4/ip_output.c:237
 __ip_finish_output.part.0+0x1b4/0x350 net/ipv4/ip_output.c:315
 __ip_finish_output net/ipv4/ip_output.c:303 [inline]
 ip_finish_output net/ipv4/ip_output.c:325 [inline]
 NF_HOOK_COND include/linux/netfilter.h:307 [inline]
 ip_output+0x35f/0xa90 net/ipv4/ip_output.c:438
 dst_output include/net/dst.h:464 [inline]
 ip_local_out net/ipv4/ip_output.c:131 [inline]
 __ip_queue_xmit+0x1bee/0x2330 net/ipv4/ip_output.c:534
 __tcp_transmit_skb+0x2cae/0x48b0 net/ipv4/tcp_output.c:1631
 __tcp_send_ack.part.0+0x4ca/0x910 net/ipv4/tcp_output.c:4464
 __tcp_send_ack net/ipv4/tcp_output.c:4470 [inline]
 tcp_send_ack+0x84/0xa0 net/ipv4/tcp_output.c:4470
 __tcp_ack_snd_check+0x1fe/0xa00 net/ipv4/tcp_input.c:5932
 tcp_ack_snd_check net/ipv4/tcp_input.c:5986 [inline]
 tcp_ack_snd_check net/ipv4/tcp_input.c:5980 [inline]
 tcp_rcv_established+0xb94/0x36e0 net/ipv4/tcp_input.c:6477
 tcp_v4_do_rcv+0xc65/0x10a0 net/ipv4/tcp_ipv4.c:1881
 tcp_v4_rcv+0x3077/0x4db0 net/ipv4/tcp_ipv4.c:2324
 ip_protocol_deliver_rcu+0xba/0x4c0 net/ipv4/ip_input.c:207
 ip_local_deliver_finish+0x3f2/0x720 net/ipv4/ip_input.c:241
 NF_HOOK include/linux/netfilter.h:318 [inline]
 NF_HOOK include/linux/netfilter.h:312 [inline]
 ip_local_deliver+0x18e/0x1f0 net/ipv4/ip_input.c:262
 dst_input include/net/dst.h:474 [inline]
 ip_sublist_rcv_finish+0x2ce/0x660 net/ipv4/ip_input.c:584
 ip_list_rcv_finish+0x590/0x780 net/ipv4/ip_input.c:636
 ip_sublist_rcv net/ipv4/ip_input.c:644 [inline]
 ip_list_rcv+0x335/0x450 net/ipv4/ip_input.c:678
 __netif_receive_skb_list_ptype net/core/dev.c:6182 [inline]
 __netif_receive_skb_list_core+0x752/0x950 net/core/dev.c:6229
 __netif_receive_skb_list net/core/dev.c:6281 [inline]
 netif_receive_skb_list_internal+0x75f/0xdc0 net/core/dev.c:6372
 gro_normal_list include/net/gro.h:524 [inline]
 gro_normal_list include/net/gro.h:520 [inline]
 gro_flush_normal include/net/gro.h:532 [inline]
 napi_complete_done+0x231/0x990 net/core/dev.c:6741
 virtqueue_napi_complete drivers/net/virtio_net.c:766 [inline]
 virtnet_poll+0x1cf5/0x3e00 drivers/net/virtio_net.c:3144
 __napi_poll.constprop.0+0xb3/0x540 net/core/dev.c:7668
 napi_poll net/core/dev.c:7731 [inline]
 net_rx_action+0x9f9/0xfa0 net/core/dev.c:7883
 handle_softirqs+0x219/0x950 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 common_interrupt+0xbf/0xe0 arch/x86/kernel/irq.c:319
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688

Freed by task 14883:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x60 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:2540 [inline]
 slab_free mm/slub.c:6670 [inline]
 kmem_cache_free+0x2d8/0x770 mm/slub.c:6781
 kfree_skbmem+0x1a4/0x1f0 net/core/skbuff.c:1130
 __kfree_skb net/core/skbuff.c:1197 [inline]
 sk_skb_reason_drop+0x136/0x1a0 net/core/skbuff.c:1234
 packet_rcv+0x16c/0x17a0 net/packet/af_packet.c:2223
 dev_queue_xmit_nit+0x75a/0xac0 net/core/dev.c:2587
 xmit_one net/core/dev.c:3849 [inline]
 dev_hard_start_xmit+0x56b/0x6e0 net/core/dev.c:3869
 sch_direct_xmit+0x1b2/0xcd0 net/sched/sch_generic.c:347
 __dev_xmit_skb net/core/dev.c:4169 [inline]
 __dev_queue_xmit+0x14a6/0x46b0 net/core/dev.c:4785
 dev_queue_xmit include/linux/netdevice.h:3381 [inline]
 neigh_hh_output include/net/neighbour.h:540 [inline]
 neigh_output include/net/neighbour.h:554 [inline]
 ip_finish_output2+0xc38/0x21a0 net/ipv4/ip_output.c:237
 __ip_finish_output.part.0+0x1b4/0x350 net/ipv4/ip_output.c:315
 __ip_finish_output net/ipv4/ip_output.c:303 [inline]
 ip_finish_output net/ipv4/ip_output.c:325 [inline]
 NF_HOOK_COND include/linux/netfilter.h:307 [inline]
 ip_output+0x35f/0xa90 net/ipv4/ip_output.c:438
 dst_output include/net/dst.h:464 [inline]
 ip_local_out net/ipv4/ip_output.c:131 [inline]
 __ip_queue_xmit+0x1bee/0x2330 net/ipv4/ip_output.c:534
 __tcp_transmit_skb+0x2cae/0x48b0 net/ipv4/tcp_output.c:1631
 __tcp_send_ack.part.0+0x4ca/0x910 net/ipv4/tcp_output.c:4464
 __tcp_send_ack net/ipv4/tcp_output.c:4470 [inline]
 tcp_send_ack+0x84/0xa0 net/ipv4/tcp_output.c:4470
 __tcp_ack_snd_check+0x1fe/0xa00 net/ipv4/tcp_input.c:5932
 tcp_ack_snd_check net/ipv4/tcp_input.c:5986 [inline]
 tcp_ack_snd_check net/ipv4/tcp_input.c:5980 [inline]
 tcp_rcv_established+0xb94/0x36e0 net/ipv4/tcp_input.c:6477
 tcp_v4_do_rcv+0xc65/0x10a0 net/ipv4/tcp_ipv4.c:1881
 tcp_v4_rcv+0x3077/0x4db0 net/ipv4/tcp_ipv4.c:2324
 ip_protocol_deliver_rcu+0xba/0x4c0 net/ipv4/ip_input.c:207
 ip_local_deliver_finish+0x3f2/0x720 net/ipv4/ip_input.c:241
 NF_HOOK include/linux/netfilter.h:318 [inline]
 NF_HOOK include/linux/netfilter.h:312 [inline]
 ip_local_deliver+0x18e/0x1f0 net/ipv4/ip_input.c:262
 dst_input include/net/dst.h:474 [inline]
 ip_sublist_rcv_finish+0x2ce/0x660 net/ipv4/ip_input.c:584
 ip_list_rcv_finish+0x590/0x780 net/ipv4/ip_input.c:636
 ip_sublist_rcv net/ipv4/ip_input.c:644 [inline]
 ip_list_rcv+0x335/0x450 net/ipv4/ip_input.c:678
 __netif_receive_skb_list_ptype net/core/dev.c:6182 [inline]
 __netif_receive_skb_list_core+0x752/0x950 net/core/dev.c:6229
 __netif_receive_skb_list net/core/dev.c:6281 [inline]
 netif_receive_skb_list_internal+0x75f/0xdc0 net/core/dev.c:6372
 gro_normal_list include/net/gro.h:524 [inline]
 gro_normal_list include/net/gro.h:520 [inline]
 gro_flush_normal include/net/gro.h:532 [inline]
 napi_complete_done+0x231/0x990 net/core/dev.c:6741
 virtqueue_napi_complete drivers/net/virtio_net.c:766 [inline]
 virtnet_poll+0x1cf5/0x3e00 drivers/net/virtio_net.c:3144
 __napi_poll.constprop.0+0xb3/0x540 net/core/dev.c:7668
 napi_poll net/core/dev.c:7731 [inline]
 net_rx_action+0x9f9/0xfa0 net/core/dev.c:7883
 handle_softirqs+0x219/0x950 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 common_interrupt+0xbf/0xe0 arch/x86/kernel/irq.c:319
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688

The buggy address belongs to the object at ffff888038e163c0
 which belongs to the cache skbuff_head_cache of size 240
The buggy address is located 0 bytes inside of
 freed 240-byte region [ffff888038e163c0, ffff888038e164b0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x38e16
memcg:ffff88803095ed81
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88823be08f00 ffffea0001efd480 dead000000000002
raw: 0000000000000000 00000000000c000c 00000000f5000000 ffff88803095ed81
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 10319, tgid 10317 (syz.2.789), ts 458870492491, free_ts 458829691688
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1857
 prep_new_page mm/page_alloc.c:1865 [inline]
 get_page_from_freelist+0xd0b/0x31a0 mm/page_alloc.c:3915
 __alloc_frozen_pages_noprof+0x25f/0x2430 mm/page_alloc.c:5210
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486
 alloc_slab_page mm/slub.c:3075 [inline]
 allocate_slab mm/slub.c:3248 [inline]
 new_slab+0x2c3/0x430 mm/slub.c:3302
 ___slab_alloc+0xe18/0x1c90 mm/slub.c:4656
 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4779
 __slab_alloc_node mm/slub.c:4855 [inline]
 slab_alloc_node mm/slub.c:5251 [inline]
 kmem_cache_alloc_node_noprof+0x44a/0x800 mm/slub.c:5315
 __alloc_skb+0x156/0x410 net/core/skbuff.c:679
 __pskb_copy_fclone+0xef/0xb50 net/core/skbuff.c:2201
 __pskb_copy include/linux/skbuff.h:1447 [inline]
 tipc_sk_mcast_rcv+0x52d/0xfa0 net/tipc/socket.c:1245
 tipc_mcast_xmit+0x711/0xfe0 net/tipc/bcast.c:424
 tipc_send_group_bcast+0x803/0xa50 net/tipc/socket.c:1130
 __tipc_sendmsg+0x4ab/0x1970 net/tipc/socket.c:1432
 tipc_sendmsg+0x4f/0x70 net/tipc/socket.c:1399
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 ____sys_sendmsg+0xa5d/0xc30 net/socket.c:2592
page last free pid 10336 tgid 10327 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1406 [inline]
 __free_frozen_pages+0x7df/0x1170 mm/page_alloc.c:2943
 vfree+0x1fd/0xb50 mm/vmalloc.c:3466
 snd_dma_free_pages+0xd2/0x130 sound/core/memalloc.c:132
 do_free_pages sound/core/pcm_memory.c:88 [inline]
 do_free_pages sound/core/pcm_memory.c:83 [inline]
 snd_pcm_lib_free_pages+0x172/0x390 sound/core/pcm_memory.c:495
 do_hw_free sound/core/pcm_native.c:911 [inline]
 snd_pcm_release_substream.part.0+0x2a8/0x340 sound/core/pcm_native.c:2735
 snd_pcm_release_substream+0x5b/0x70 sound/core/pcm_native.c:2729
 snd_pcm_oss_release_file sound/core/oss/pcm_oss.c:2396 [inline]
 snd_pcm_oss_release_file sound/core/oss/pcm_oss.c:2388 [inline]
 snd_pcm_oss_release+0x135/0x310 sound/core/oss/pcm_oss.c:2575
 __fput+0x402/0xb70 fs/file_table.c:468
 task_work_run+0x150/0x240 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
 exit_to_user_mode_loop+0xfb/0x540 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888038e16280: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888038e16300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
>ffff888038e16380: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
                                           ^
 ffff888038e16400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888038e16480: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
==================================================================