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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 ffff88805c4a23c0 by task syz.1.487/8365

CPU: 0 UID: 0 PID: 8365 Comm: syz.1.487 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+0xa21/0x12e0 fs/splice.c:738
 do_splice_from fs/splice.c:938 [inline]
 direct_splice_actor+0x18f/0x6c0 fs/splice.c:1161
 splice_direct_to_actor+0x342/0xa30 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: 0033:0x7f4667b8eec9
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:00007f4668a07038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f4667de6180 RCX: 00007f4667b8eec9
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 0000000000000008
RBP: 00007f4667c11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4667de6218 R14: 00007f4667de6180 R15: 00007ffdac35ea38
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88805c4a2690 pfn:0x5c4a2
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f0(buddy)
raw: 00fff00000000000 ffffea0001a17f08 ffffea0001767588 0000000000000000
raw: ffff88805c4a2690 0000000000000001 00000000f0000000 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 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 7821, tgid 7813 (syz.0.381), ts 182115139315, free_ts 197739414349
 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_slab_page mm/slub.c:3030 [inline]
 allocate_slab mm/slub.c:3203 [inline]
 new_slab+0x24a/0x360 mm/slub.c:3257
 ___slab_alloc+0xdc4/0x1ae0 mm/slub.c:4627
 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4746
 __slab_alloc_node mm/slub.c:4822 [inline]
 slab_alloc_node mm/slub.c:5233 [inline]
 kmem_cache_alloc_noprof+0x43f/0x6e0 mm/slub.c:5252
 __kernfs_new_node+0xd2/0x8e0 fs/kernfs/dir.c:637
 kernfs_new_node+0x13c/0x1e0 fs/kernfs/dir.c:713
 __kernfs_create_file+0x53/0x350 fs/kernfs/file.c:1057
 sysfs_add_file_mode_ns+0x207/0x3c0 fs/sysfs/file.c:313
 create_files fs/sysfs/group.c:76 [inline]
 internal_create_group+0x578/0xf30 fs/sysfs/group.c:183
 internal_create_groups+0x9d/0x150 fs/sysfs/group.c:223
 device_add_groups drivers/base/core.c:2836 [inline]
 device_add_attrs drivers/base/core.c:2911 [inline]
 device_add+0xf30/0x1aa0 drivers/base/core.c:3643
 netdev_register_kobject+0x1a9/0x3d0 net/core/net-sysfs.c:2358
page last free pid 8149 tgid 8138 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
 discard_slab mm/slub.c:3301 [inline]
 __put_partials+0x130/0x170 mm/slub.c:3848
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:352
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4946 [inline]
 slab_alloc_node mm/slub.c:5245 [inline]
 kmem_cache_alloc_node_noprof+0x28a/0x770 mm/slub.c:5297
 zswap_entry_cache_alloc mm/zswap.c:702 [inline]
 zswap_store_page mm/zswap.c:1423 [inline]
 zswap_store+0x850/0x2830 mm/zswap.c:1540
 swap_writeout+0x3f4/0x1090 mm/page_io.c:275
 writeout mm/vmscan.c:662 [inline]
 pageout mm/vmscan.c:721 [inline]
 shrink_folio_list+0x3e50/0x4800 mm/vmscan.c:1453
 reclaim_folio_list+0xda/0x5d0 mm/vmscan.c:2233
 reclaim_pages+0x3ec/0x570 mm/vmscan.c:2270
 madvise_cold_or_pageout_pte_range+0x14e5/0x20d0 mm/madvise.c:565
 walk_pmd_range mm/pagewalk.c:130 [inline]
 walk_pud_range mm/pagewalk.c:224 [inline]
 walk_p4d_range mm/pagewalk.c:262 [inline]
 walk_pgd_range+0xc05/0x1f50 mm/pagewalk.c:303
 __walk_page_range+0x163/0x820 mm/pagewalk.c:410
 walk_page_range_vma+0x2c7/0xa20 mm/pagewalk.c:717
 madvise_pageout_page_range mm/madvise.c:624 [inline]
 madvise_pageout+0x257/0x540 mm/madvise.c:649

Memory state around the buggy address:
 ffff88805c4a2280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88805c4a2300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88805c4a2380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                           ^
 ffff88805c4a2400: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88805c4a2480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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