================================================================== 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+0xa03/0xc70 drivers/video/fbdev/core/fbcon.c:623 Read of size 256 at addr ffff8880599f9fc0 by task syz.0.714/9819 CPU: 0 UID: 0 PID: 9819 Comm: syz.0.714 Tainted: G U W L XTNJ syzkaller #0 PREEMPT(full) Tainted: [U]=USER, [W]=WARN, [L]=SOFTLOCKUP, [X]=AUX, [T]=RANDSTRUCT, [N]=TEST, [J]=FWCTL Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: __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:623 fbcon_init+0xd77/0x1900 drivers/video/fbdev/core/fbcon.c:1156 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+0xa24/0x12e0 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/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f990098eec9 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:00007f9901864038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f9900be6270 RCX: 00007f990098eec9 RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000003 RBP: 00007f9900a11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9900be6308 R14: 00007f9900be6270 R15: 00007ffc43bd14a8 Allocated by task 9783: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5627 [inline] __kmalloc_node_track_caller_noprof+0x345/0x8a0 mm/slub.c:5736 kmemdup_noprof+0x29/0x60 mm/util.c:138 kmemdup_noprof include/linux/fortify-string.h:765 [inline] neigh_sysctl_register+0xb2/0x670 net/core/neighbour.c:3826 addrconf_sysctl_register+0xb9/0x1f0 net/ipv6/addrconf.c:7367 ipv6_add_dev+0xb31/0x15f0 net/ipv6/addrconf.c:460 addrconf_notify+0x53e/0x19e0 net/ipv6/addrconf.c:3650 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2229 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline] call_netdevice_notifiers net/core/dev.c:2281 [inline] register_netdevice+0x182e/0x2270 net/core/dev.c:11332 register_netdev+0x34/0x50 net/core/dev.c:11410 ip6_tnl_init_net+0x2c7/0x4d0 net/ipv6/ip6_tunnel.c:2308 ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137 setup_net+0x100/0x390 net/core/net_namespace.c:445 copy_net_ns+0x2f8/0x690 net/core/net_namespace.c:580 create_new_namespaces+0x3ea/0xa90 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:218 ksys_unshare+0x45b/0xa40 kernel/fork.c:3129 __do_sys_unshare kernel/fork.c:3200 [inline] __se_sys_unshare kernel/fork.c:3198 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3198 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880599f9000 which belongs to the cache kmalloc-cg-2k of size 2048 The buggy address is located 2848 bytes to the right of allocated 1184-byte region [ffff8880599f9000, ffff8880599f94a0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x599f8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88805d1acc01 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813ffb03c0 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000080008 00000000f5000000 ffff88805d1acc01 head: 00fff00000000040 ffff88813ffb03c0 dead000000000122 0000000000000000 head: 0000000000000000 0000000000080008 00000000f5000000 ffff88805d1acc01 head: 00fff00000000003 ffffea0001667e01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 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 9783, tgid 9780 (syz.1.710), ts 396355173558, free_ts 387404259444 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1850 prep_new_page mm/page_alloc.c:1858 [inline] get_page_from_freelist+0x10a3/0x3a30 mm/page_alloc.c:3884 __alloc_frozen_pages_noprof+0x25f/0x2470 mm/page_alloc.c:5183 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3039 [inline] allocate_slab mm/slub.c:3212 [inline] new_slab+0x24a/0x360 mm/slub.c:3266 ___slab_alloc+0xdc4/0x1ae0 mm/slub.c:4636 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4755 __slab_alloc_node mm/slub.c:4831 [inline] slab_alloc_node mm/slub.c:5253 [inline] __kmalloc_cache_noprof+0x477/0x780 mm/slub.c:5743 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] ipv6_add_dev+0x1c9/0x15f0 net/ipv6/addrconf.c:388 addrconf_notify+0x53e/0x19e0 net/ipv6/addrconf.c:3650 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2229 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline] call_netdevice_notifiers net/core/dev.c:2281 [inline] register_netdevice+0x182e/0x2270 net/core/dev.c:11332 register_netdev+0x34/0x50 net/core/dev.c:11410 ip6_tnl_init_net+0x2c7/0x4d0 net/ipv6/ip6_tunnel.c:2308 ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137 page last free pid 5816 tgid 5816 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2906 __folio_put+0x329/0x450 mm/swap.c:112 folio_put include/linux/mm.h:1425 [inline] put_page include/linux/mm.h:1494 [inline] put_netmem net/core/skbuff.c:7375 [inline] skb_page_unref include/linux/skbuff_ref.h:43 [inline] __skb_frag_unref include/linux/skbuff_ref.h:56 [inline] skb_release_data+0x81a/0x9e0 net/core/skbuff.c:1081 skb_release_all net/core/skbuff.c:1152 [inline] __kfree_skb+0x4f/0x70 net/core/skbuff.c:1166 tcp_wmem_free_skb include/net/tcp.h:332 [inline] tcp_rtx_queue_unlink_and_free include/net/tcp.h:2205 [inline] tcp_clean_rtx_queue net/ipv4/tcp_input.c:3471 [inline] tcp_ack+0x1d37/0x5fc0 net/ipv4/tcp_input.c:4096 tcp_rcv_established+0x10ea/0x3700 net/ipv4/tcp_input.c:6341 tcp_v4_do_rcv+0x5ca/0xa90 net/ipv4/tcp_ipv4.c:1931 tcp_v4_rcv+0x3077/0x47d0 net/ipv4/tcp_ipv4.c:2374 ip_protocol_deliver_rcu+0xba/0x4c0 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x3f2/0x720 net/ipv4/ip_input.c:239 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:260 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:6122 [inline] __netif_receive_skb_list_core+0x752/0x950 net/core/dev.c:6169 __netif_receive_skb_list net/core/dev.c:6221 [inline] netif_receive_skb_list_internal+0x75f/0xdc0 net/core/dev.c:6312 Memory state around the buggy address: ffff8880599f9e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880599f9f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880599f9f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880599fa000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880599fa080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================