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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 ffff8880371623c0 by task syz.0.945/9746

CPU: 1 UID: 0 PID: 9746 Comm: syz.0.945 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <TASK>
 __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: 0033:0x7f6b7278efc9
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:00007f6b736fd038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f6b729e5fa0 RCX: 00007f6b7278efc9
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000003
RBP: 00007f6b72811f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6b729e6038 R14: 00007f6b729e5fa0 R15: 00007ffcbe5ccf18
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x37162
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 0000000000000000 ffffea0000dc5890 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 5, migratetype Unmovable, gfp_mask 0x152c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 8461, tgid 8459 (syz.3.560), ts 274820916354, free_ts 275354432053
 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_mpol+0x1fb/0x550 mm/mempolicy.c:2416
 alloc_pages_noprof mm/mempolicy.c:2507 [inline]
 folio_alloc_noprof+0x20/0x2d0 mm/mempolicy.c:2517
 filemap_alloc_folio_noprof+0x3a1/0x470 mm/filemap.c:1020
 ractl_alloc_folio mm/readahead.c:189 [inline]
 ra_alloc_folio mm/readahead.c:446 [inline]
 page_cache_ra_order+0x56f/0xf20 mm/readahead.c:512
 page_cache_async_ra+0x74b/0xc70 mm/readahead.c:697
 do_async_mmap_readahead mm/filemap.c:3376 [inline]
 filemap_fault+0xda5/0x29a0 mm/filemap.c:3475
 __do_fault+0x10d/0x490 mm/memory.c:5280
 do_read_fault mm/memory.c:5698 [inline]
 do_fault mm/memory.c:5832 [inline]
 do_pte_missing+0xf4a/0x3ba0 mm/memory.c:4361
 handle_pte_fault mm/memory.c:6177 [inline]
 __handle_mm_fault+0x1556/0x2aa0 mm/memory.c:6318
 handle_mm_fault+0x589/0xd10 mm/memory.c:6487
 faultin_page mm/gup.c:1126 [inline]
 __get_user_pages+0x54e/0x3530 mm/gup.c:1428
 populate_vma_page_range+0x267/0x3f0 mm/gup.c:1860
 __mm_populate+0x1d8/0x380 mm/gup.c:1963
page last free pid 8465 tgid 8459 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 free_unref_folios+0xa31/0x1610 mm/page_alloc.c:2963
 folios_put_refs+0x4be/0x750 mm/swap.c:1002
 folio_batch_release include/linux/pagevec.h:101 [inline]
 truncate_inode_pages_range+0x311/0xe50 mm/truncate.c:383
 kill_bdev block/bdev.c:91 [inline]
 blkdev_flush_mapping+0xfb/0x290 block/bdev.c:712
 blkdev_put_whole+0xc4/0xf0 block/bdev.c:719
 bdev_release+0x47e/0x6d0 block/bdev.c:1144
 blkdev_release+0x15/0x20 block/fops.c:709
 __fput+0x402/0xb70 fs/file_table.c:468
 task_work_run+0x150/0x240 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x86f/0x2bf0 kernel/exit.c:966
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1107
 get_signal+0x2671/0x26d0 kernel/signal.c:3034
 arch_do_signal_or_restart+0x8f/0x790 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x85/0x130 kernel/entry/common.c:40
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x426/0xfa0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888037162280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888037162300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888037162380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                           ^
 ffff888037162400: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888037162480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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