================================================================== 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 ffff8880614163c0 by task syz.2.2631/18527 CPU: 1 UID: 0 PID: 18527 Comm: syz.2.2631 Tainted: G U syzkaller #0 PREEMPT(full) Tainted: [U]=USER Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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+0xef/0x150 fs/sysfs/file.c:142 kernfs_fop_write_iter+0x3ac/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: 0033:0x7f7a94b8eec9 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:00007f7a95b06038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f7a94de5fa0 RCX: 00007f7a94b8eec9 RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000007 RBP: 00007f7a94c11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7a94de6038 R14: 00007f7a94de5fa0 R15: 00007fff35dd6ee8 The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888061416000 pfn:0x61416 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea0001ed6f48 ffffea000157a0c8 0000000000000000 raw: ffff888061416000 ffff88823be18e00 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 0x2cc2(GFP_KERNEL|__GFP_HIGHMEM|__GFP_NOWARN), pid 18469, tgid 18468 (syz.0.2617), ts 822928298237, free_ts 823442001553 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+0xb/0x1b0 mm/page_alloc.c:5217 __alloc_pages_node_noprof include/linux/gfp.h:284 [inline] alloc_pages_node_noprof include/linux/gfp.h:311 [inline] pcpu_alloc_pages mm/percpu-vm.c:95 [inline] pcpu_populate_chunk+0x110/0xb00 mm/percpu-vm.c:285 pcpu_alloc_noprof+0x86a/0x14c0 mm/percpu.c:1870 bpf_map_alloc_percpu+0x9a/0x4b0 kernel/bpf/syscall.c:560 prealloc_init kernel/bpf/hashtab.c:344 [inline] htab_map_alloc+0x10ca/0x1570 kernel/bpf/hashtab.c:569 map_create+0x65c/0x27e0 kernel/bpf/syscall.c:1497 __sys_bpf+0x3d9d/0x4980 kernel/bpf/syscall.c:6116 __do_sys_bpf kernel/bpf/syscall.c:6244 [inline] __se_sys_bpf kernel/bpf/syscall.c:6242 [inline] __x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:6242 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 17106 tgid 17106 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 pcpu_free_pages.constprop.0+0x126/0x210 mm/percpu-vm.c:65 pcpu_reclaim_populated mm/percpu.c:2152 [inline] pcpu_balance_workfn+0x26b/0xe00 mm/percpu.c:2208 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+0x3c2/0x780 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: ffff888061416280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888061416300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff888061416380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff888061416400: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888061416480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================