================================================================== BUG: KASAN: use-after-free in scr_memcpyw include/linux/vt_buffer.h:38 [inline] BUG: KASAN: use-after-free in fbcon_prepare_logo+0xa03/0xc70 drivers/video/fbdev/core/fbcon.c:623 Read of size 256 at addr ffff8880b26423c0 by task syz.2.2408/18330 CPU: 0 UID: 0 PID: 18330 Comm: syz.2.2408 Not tainted syzkaller #0 PREEMPT(full) 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: 0033:0x7fd44538f6c9 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:00007fd446242038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fd4455e5fa0 RCX: 00007fd44538f6c9 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000003 RBP: 00007fd445411f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd4455e6038 R14: 00007fd4455e5fa0 R15: 00007ffe5bc71ca8 The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xb2642 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 dead000000000100 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 0, migratetype Unmovable, gfp_mask 0xcc0(GFP_KERNEL), pid 18035, tgid 18033 (syz.2.2332), ts 1023553229504, free_ts 1023687379445 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_noprof mm/page_alloc.c:5217 [inline] alloc_pages_bulk_noprof+0x71c/0x1410 mm/page_alloc.c:5137 ___alloc_pages_bulk mm/kasan/shadow.c:345 [inline] __kasan_populate_vmalloc mm/kasan/shadow.c:370 [inline] kasan_populate_vmalloc+0x112/0x2d0 mm/kasan/shadow.c:435 alloc_vmap_area+0x960/0x29e0 mm/vmalloc.c:2098 __get_vm_area_node+0x1ca/0x330 mm/vmalloc.c:3193 __vmalloc_node_range_noprof+0x271/0x1480 mm/vmalloc.c:3857 __kvmalloc_node_noprof+0x431/0x9c0 mm/slub.c:7122 kvmalloc_array_node_noprof include/linux/slab.h:1122 [inline] prepare_klistmount fs/namespace.c:5925 [inline] __do_sys_listmount+0x280/0xeb0 fs/namespace.c:5964 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 page last free pid 5823 tgid 5823 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 kasan_depopulate_vmalloc_pte+0x5b/0x80 mm/kasan/shadow.c:495 apply_to_pte_range mm/memory.c:3142 [inline] apply_to_pmd_range mm/memory.c:3186 [inline] apply_to_pud_range mm/memory.c:3222 [inline] apply_to_p4d_range mm/memory.c:3258 [inline] __apply_to_page_range+0xac1/0x13f0 mm/memory.c:3294 kasan_release_vmalloc+0xd1/0xe0 mm/kasan/shadow.c:616 kasan_release_vmalloc_node mm/vmalloc.c:2255 [inline] purge_vmap_node+0x1c4/0xa30 mm/vmalloc.c:2272 __purge_vmap_area_lazy+0xa06/0xc60 mm/vmalloc.c:2362 drain_vmap_area_work+0x27/0x40 mm/vmalloc.c:2396 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 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: ffff8880b2642280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8880b2642300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8880b2642380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8880b2642400: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8880b2642480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================