================================================================== BUG: KASAN: slab-out-of-bounds in scr_memcpyw include/linux/vt_buffer.h:49 [inline] BUG: KASAN: slab-out-of-bounds in fbcon_prepare_logo+0x48a/0xb50 drivers/video/fbdev/core/fbcon.c:600 Read of size 218 at addr ffff888073e874aa by task syz.4.349/5569 CPU: 0 PID: 5569 Comm: syz.4.349 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0xa8/0x210 mm/kasan/report.c:420 kasan_report+0x10b/0x140 mm/kasan/report.c:524 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x235/0x290 mm/kasan/generic.c:189 memcpy+0x25/0x60 mm/kasan/shadow.c:65 scr_memcpyw include/linux/vt_buffer.h:49 [inline] fbcon_prepare_logo+0x48a/0xb50 drivers/video/fbdev/core/fbcon.c:600 fbcon_init+0x137c/0x2460 drivers/video/fbdev/core/fbcon.c:1135 visual_init+0x2dd/0x650 drivers/tty/vt/vt.c:1074 do_bind_con_driver+0x859/0x1030 drivers/tty/vt/vt.c:3704 vt_bind drivers/tty/vt/vt.c:3860 [inline] store_bind+0x794/0xa20 drivers/tty/vt/vt.c:3932 kernfs_fop_write_iter+0x3a0/0x520 fs/kernfs/file.c:352 call_write_iter include/linux/fs.h:2271 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x482/0x9a0 fs/read_write.c:584 ksys_write+0x14d/0x260 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f23df99e559 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:00007f23e07a8028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f23dfc26090 RCX: 00007f23df99e559 RDX: 0000000000000001 RSI: 0000200000000e80 RDI: 0000000000000003 RBP: 00007f23dfa35ab8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f23dfc26128 R14: 00007f23dfc26090 R15: 00007ffc4ec46428 Allocated by task 5569: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:384 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slab_common.c:936 [inline] __kmalloc+0xb3/0x240 mm/slab_common.c:949 kmalloc include/linux/slab.h:568 [inline] kzalloc include/linux/slab.h:699 [inline] vc_do_resize+0x36e/0x17b0 drivers/tty/vt/vt.c:1244 fbcon_init+0x1395/0x2460 drivers/video/fbdev/core/fbcon.c:1132 visual_init+0x2dd/0x650 drivers/tty/vt/vt.c:1074 do_bind_con_driver+0x859/0x1030 drivers/tty/vt/vt.c:3704 vt_bind drivers/tty/vt/vt.c:3860 [inline] store_bind+0x794/0xa20 drivers/tty/vt/vt.c:3932 kernfs_fop_write_iter+0x3a0/0x520 fs/kernfs/file.c:352 call_write_iter include/linux/fs.h:2271 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x482/0x9a0 fs/read_write.c:584 ksys_write+0x14d/0x260 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff888073e86000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1194 bytes to the right of 4096-byte region [ffff888073e86000, ffff888073e87000) The buggy address belongs to the physical page: page:ffffea0001cfa000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x73e80 head:ffffea0001cfa000 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001da4e00 dead000000000002 ffff888018442140 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 4715, tgid 4714 (syz.2.103), ts 101062466467, free_ts 99273393830 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2560 prep_new_page mm/page_alloc.c:2567 [inline] get_page_from_freelist+0x206b/0x2180 mm/page_alloc.c:4358 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5658 alloc_slab_page+0x5d/0x180 mm/slub.c:1799 allocate_slab mm/slub.c:1944 [inline] new_slab+0x87/0x2d0 mm/slub.c:1997 ___slab_alloc+0xbc5/0x1240 mm/slub.c:3154 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] __kmem_cache_alloc_node+0x126/0x270 mm/slub.c:3398 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc+0xa3/0x240 mm/slab_common.c:949 kmalloc include/linux/slab.h:568 [inline] sk_prot_alloc+0xe7/0x210 net/core/sock.c:2056 sk_alloc+0x36/0x330 net/core/sock.c:2112 packet_create+0xfb/0x770 net/packet/af_packet.c:3435 __sock_create+0x49a/0x940 net/socket.c:1550 sock_create net/socket.c:1606 [inline] __sys_socket_create net/socket.c:1643 [inline] __sys_socket+0xc4/0x190 net/socket.c:1671 __do_sys_socket net/socket.c:1684 [inline] __se_sys_socket net/socket.c:1682 [inline] __x64_sys_socket+0x76/0x80 net/socket.c:1682 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1487 [inline] free_pcp_prepare mm/page_alloc.c:1537 [inline] free_unref_page_prepare+0x8e5/0x9e0 mm/page_alloc.c:3414 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3509 free_slab mm/slub.c:2036 [inline] discard_slab mm/slub.c:2042 [inline] __unfreeze_partials+0x188/0x1e0 mm/slub.c:2591 put_cpu_partial+0x17c/0x250 mm/slub.c:2667 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x490 mm/slab.h:737 slab_alloc_node mm/slub.c:3359 [inline] kmem_cache_alloc_node+0x1ad/0x310 mm/slub.c:3404 __alloc_skb+0xf9/0x7d0 net/core/skbuff.c:505 alloc_skb include/linux/skbuff.h:1303 [inline] nlmsg_new include/net/netlink.h:998 [inline] inet_netconf_notify_devconf+0x16f/0x230 net/ipv4/devinet.c:2128 __devinet_sysctl_unregister net/ipv4/devinet.c:2639 [inline] devinet_sysctl_unregister net/ipv4/devinet.c:2663 [inline] inetdev_destroy net/ipv4/devinet.c:329 [inline] inetdev_event+0x6fa/0x13f0 net/ipv4/devinet.c:1615 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455 call_netdevice_notifiers_extack net/core/dev.c:2052 [inline] call_netdevice_notifiers net/core/dev.c:2066 [inline] unregister_netdevice_many_notify+0x10b1/0x1990 net/core/dev.c:11024 unregister_netdevice_many net/core/dev.c:11078 [inline] default_device_exit_batch+0x95e/0x9f0 net/core/dev.c:11550 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x78e/0xba0 net/core/net_namespace.c:640 Memory state around the buggy address: ffff888073e87380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888073e87400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888073e87480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888073e87500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888073e87580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================