================================================================== 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:686 Read of size 26 at addr ffff8880892b4cea by task syz.4.4609/27274 CPU: 0 UID: 0 PID: 27274 Comm: syz.4.4609 Tainted: G U L syzkaller #0 PREEMPT(full) Tainted: [U]=USER, [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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+0x13d/0x4b0 mm/kasan/report.c:482 kasan_report+0xdf/0x1d0 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:686 fbcon_init+0x1065/0x1830 drivers/video/fbdev/core/fbcon.c:1228 visual_init+0x320/0x620 drivers/tty/vt/vt.c:1048 do_bind_con_driver.isra.0+0x636/0x9c0 drivers/tty/vt/vt.c:4056 vt_bind drivers/tty/vt/vt.c:4212 [inline] store_bind+0x609/0x730 drivers/tty/vt/vt.c:4284 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+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3e0259cdd9 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:00007f3e03440028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f3e02816180 RCX: 00007f3e0259cdd9 RDX: 000000000008083a RSI: 00002000000000c0 RDI: 0000000000000002 RBP: 00007f3e02632d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3e02816218 R14: 00007f3e02816180 R15: 00007ffc8b0a2778 Allocated by task 15430: 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:5295 [inline] __kmalloc_noprof+0x301/0x850 mm/slub.c:5307 kmalloc_noprof include/linux/slab.h:954 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] new_dir fs/proc/proc_sysctl.c:966 [inline] get_subdir fs/proc/proc_sysctl.c:1010 [inline] sysctl_mkdir_p fs/proc/proc_sysctl.c:1320 [inline] __register_sysctl_table+0xbe4/0x1650 fs/proc/proc_sysctl.c:1395 __addrconf_sysctl_register+0x1a2/0x360 net/ipv6/addrconf.c:7335 addrconf_sysctl_register net/ipv6/addrconf.c:7383 [inline] addrconf_sysctl_register+0x163/0x200 net/ipv6/addrconf.c:7372 ipv6_add_dev+0xaf2/0x1520 net/ipv6/addrconf.c:460 addrconf_notify+0x5db/0x1ba0 net/ipv6/addrconf.c:3662 notifier_call_chain+0x99/0x400 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+0x18fe/0x24b0 net/core/dev.c:11458 cfg80211_register_netdevice+0x149/0x310 net/wireless/core.c:1635 ieee80211_if_add+0x103d/0x1920 net/mac80211/iface.c:2417 ieee80211_register_hw+0x3c42/0x4570 net/mac80211/main.c:1641 mac80211_hwsim_new_radio+0x2a01/0x5aa0 drivers/net/wireless/virtual/mac80211_hwsim.c:6019 hwsim_new_radio_nl+0xc5f/0x1370 drivers/net/wireless/virtual/mac80211_hwsim.c:6726 genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] __sys_sendto+0x468/0x4b0 net/socket.c:2265 __do_sys_sendto net/socket.c:2272 [inline] __se_sys_sendto net/socket.c:2268 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2268 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880892b4c00 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 44 bytes to the right of allocated 190-byte region [ffff8880892b4c00, ffff8880892b4cbe) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x892b4 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88813fe2e3c0 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 15372, tgid 15365 (syz.0.2141), ts 632281299157, free_ts 632219765853 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x153/0x170 mm/page_alloc.c:1858 prep_new_page mm/page_alloc.c:1866 [inline] get_page_from_freelist+0x11a6/0x33b0 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x27c/0x2bc0 mm/page_alloc.c:5226 alloc_slab_page mm/slub.c:3278 [inline] allocate_slab mm/slub.c:3467 [inline] new_slab+0xa6/0x6c0 mm/slub.c:3525 refill_objects+0x277/0x420 mm/slub.c:7251 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x375/0x650 mm/slub.c:4651 alloc_from_pcs mm/slub.c:4749 [inline] slab_alloc_node mm/slub.c:4883 [inline] __do_kmalloc_node mm/slub.c:5294 [inline] __kmalloc_noprof+0x688/0x850 mm/slub.c:5307 kmalloc_noprof include/linux/slab.h:954 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] new_dir fs/proc/proc_sysctl.c:966 [inline] get_subdir fs/proc/proc_sysctl.c:1010 [inline] sysctl_mkdir_p fs/proc/proc_sysctl.c:1320 [inline] __register_sysctl_table+0xbe4/0x1650 fs/proc/proc_sysctl.c:1395 neigh_sysctl_register+0x326/0x660 net/core/neighbour.c:3922 addrconf_sysctl_register+0xb9/0x200 net/ipv6/addrconf.c:7379 ipv6_add_dev+0xaf2/0x1520 net/ipv6/addrconf.c:460 addrconf_notify+0x5db/0x1ba0 net/ipv6/addrconf.c:3662 notifier_call_chain+0x99/0x400 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+0x18fe/0x24b0 net/core/dev.c:11458 register_netdev+0x34/0x50 net/core/dev.c:11536 page last free pid 15 tgid 15 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1402 [inline] __free_frozen_pages+0x747/0x1040 mm/page_alloc.c:2943 __pagetable_free include/linux/mm.h:3661 [inline] pagetable_free include/linux/mm.h:3685 [inline] pagetable_dtor_free include/linux/mm.h:3784 [inline] __tlb_remove_table include/asm-generic/tlb.h:221 [inline] __tlb_remove_table_free mm/mmu_gather.c:228 [inline] tlb_remove_table_rcu+0x2cf/0x380 mm/mmu_gather.c:291 rcu_do_batch kernel/rcu/tree.c:2617 [inline] rcu_core+0x5a2/0x10d0 kernel/rcu/tree.c:2869 handle_softirqs+0x1ea/0xa00 kernel/softirq.c:622 run_ksoftirqd kernel/softirq.c:1076 [inline] run_ksoftirqd+0x38/0x60 kernel/softirq.c:1068 smpboot_thread_fn+0x3d3/0xaa0 kernel/smpboot.c:160 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 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: ffff8880892b4b80: 00 00 00 04 fc fc fc fc fc fc fc fc fc fc fc fc ffff8880892b4c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880892b4c80: 00 00 00 00 00 00 00 06 fc fc fc fc fc fc fc fc ^ ffff8880892b4d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880892b4d80: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================