================================================================== 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 26 at addr ffff888034e0a3ea by task syz.6.2782/20264 CPU: 0 UID: 0 PID: 20264 Comm: syz.6.2782 Tainted: G U I L syzkaller #0 PREEMPT(full) Tainted: [U]=USER, [I]=FIRMWARE_WORKAROUND, [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 iter_file_splice_write+0x830/0x10a0 fs/splice.c:736 do_splice_from fs/splice.c:936 [inline] direct_splice_actor+0x192/0x6c0 fs/splice.c:1159 splice_direct_to_actor+0x345/0xa30 fs/splice.c:1103 do_splice_direct_actor fs/splice.c:1202 [inline] do_splice_direct+0x174/0x240 fs/splice.c:1228 do_sendfile+0xadc/0xe20 fs/read_write.c:1372 __do_sys_sendfile64 fs/read_write.c:1433 [inline] __se_sys_sendfile64 fs/read_write.c:1419 [inline] __x64_sys_sendfile64+0x1d8/0x220 fs/read_write.c:1419 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: 0033:0x7ff668b9c629 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:00007ff669a7a028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007ff668e16090 RCX: 00007ff668b9c629 RDX: 0000000000000000 RSI: 000000000000000c RDI: 0000000000000006 RBP: 00007ff668c32b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff668e16128 R14: 00007ff668e16090 R15: 00007ffd04ea5818 Allocated by task 20269: 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 kmalloc_noprof include/linux/slab.h:962 [inline] kzalloc_noprof include/linux/slab.h:1200 [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:11411 __ip_tunnel_create+0x52b/0x670 net/ipv4/ip_tunnel.c:268 ip_tunnel_init_net+0x230/0x780 net/ipv4/ip_tunnel.c:1147 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+0x455/0xab0 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 ffff888034e0a300 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 82 bytes to the right of allocated 152-byte region [ffff888034e0a300, ffff888034e0a398) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x34e0a flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88813fe373c0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000100010 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 0xd2c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6184, tgid 6183 (syz.3.51), ts 124562804243, free_ts 124561101537 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:3255 [inline] allocate_slab mm/slub.c:3444 [inline] new_slab+0xa6/0x6d0 mm/slub.c:3502 refill_objects+0x26b/0x400 mm/slub.c:7134 refill_sheaf mm/slub.c:2804 [inline] alloc_full_sheaf mm/slub.c:2825 [inline] __pcs_replace_empty_main+0x19f/0x600 mm/slub.c:4588 alloc_from_pcs mm/slub.c:4681 [inline] slab_alloc_node mm/slub.c:4815 [inline] __do_kmalloc_node mm/slub.c:5218 [inline] __kmalloc_node_noprof+0x69a/0x850 mm/slub.c:5225 kmalloc_node_noprof include/linux/slab.h:1093 [inline] alloc_slab_obj_exts+0x4e/0x190 mm/slub.c:2174 __memcg_slab_post_alloc_hook+0x24a/0x9a0 mm/memcontrol.c:3234 memcg_slab_post_alloc_hook mm/slub.c:2459 [inline] slab_post_alloc_hook mm/slub.c:4512 [inline] slab_alloc_node mm/slub.c:4830 [inline] kmem_cache_alloc_noprof+0x58a/0x6e0 mm/slub.c:4837 alloc_buffer_head+0x21/0x140 fs/buffer.c:3026 folio_alloc_buffers+0x2a0/0x8f0 fs/buffer.c:932 create_empty_buffers+0x3a/0x660 fs/buffer.c:1688 folio_create_buffers+0x13b/0x1a0 fs/buffer.c:1799 __block_write_begin_int+0x393/0x19c0 fs/buffer.c:2123 iomap_write_begin+0x1664/0x2340 fs/iomap/buffered-io.c:999 page last free pid 6183 tgid 6183 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 __kasan_populate_vmalloc_do mm/kasan/shadow.c:393 [inline] __kasan_populate_vmalloc+0x1ea/0x210 mm/kasan/shadow.c:424 kasan_populate_vmalloc include/linux/kasan.h:580 [inline] alloc_vmap_area+0x95d/0x2bd0 mm/vmalloc.c:2129 __get_vm_area_node+0x1ca/0x330 mm/vmalloc.c:3232 __vmalloc_node_range_noprof+0x213/0x1530 mm/vmalloc.c:4024 __vmalloc_node_noprof+0xad/0xf0 mm/vmalloc.c:4124 alloc_thread_stack_node kernel/fork.c:355 [inline] dup_task_struct kernel/fork.c:924 [inline] copy_process+0x5ec/0x7a10 kernel/fork.c:2050 kernel_clone+0xfc/0x9a0 kernel/fork.c:2654 __do_sys_clone3+0x214/0x290 kernel/fork.c:2956 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 Memory state around the buggy address: ffff888034e0a280: 00 00 00 04 fc fc fc fc fc fc fc fc fc fc fc fc ffff888034e0a300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888034e0a380: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888034e0a400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888034e0a480: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ==================================================================