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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:686
Read of size 2 at addr ffff888034075208 by task syz.9.4262/28747

CPU: 0 UID: 0 PID: 28747 Comm: syz.9.4262 Tainted: G     U       L      syzkaller #0 PREEMPT(full) 
Tainted: [U]=USER, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 __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+0x13d/0x4b0 mm/kasan/report.c:482
 kasan_report+0xdf/0x1d0 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:686
 fbcon_init+0x1065/0x1830 drivers/video/fbdev/core/fbcon.c:1228
 visual_init+0x320/0x620 drivers/tty/vt/vt.c:1048
 do_bind_con_driver.isra.0+0x636/0x9c0 drivers/tty/vt/vt.c:4056
 vt_bind drivers/tty/vt/vt.c:4212 [inline]
 store_bind+0x609/0x730 drivers/tty/vt/vt.c:4284
 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+0x115/0x840 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f94b099ce59
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:00007f94b18ee028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f94b0c16090 RCX: 00007f94b099ce59
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000005
RBP: 00007f94b0a32d6f R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000000a R11: 0000000000000246 R12: 0000000000000000
R13: 00007f94b0c16128 R14: 00007f94b0c16090 R15: 00007ffd3e45aa48
 </TASK>

Allocated by task 1:
 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
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5296 [inline]
 __kmalloc_node_track_caller_noprof+0x304/0x850 mm/slub.c:5408
 __kmemdup_nul mm/util.c:64 [inline]
 kstrdup+0x51/0xe0 mm/util.c:84
 kstrdup_const+0x63/0x80 mm/util.c:104
 __kernfs_new_node+0x9b/0x9f0 fs/kernfs/dir.c:660
 kernfs_new_node+0x11b/0x1a0 fs/kernfs/dir.c:748
 kernfs_create_dir_ns+0x4c/0x1a0 fs/kernfs/dir.c:1121
 sysfs_create_dir_ns+0x13a/0x2b0 fs/sysfs/dir.c:59
 create_dir lib/kobject.c:73 [inline]
 kobject_add_internal+0x2c8/0x930 lib/kobject.c:240
 kobject_add_varg lib/kobject.c:374 [inline]
 kobject_init_and_add+0x121/0x180 lib/kobject.c:457
 lookup_or_create_module_kobject kernel/params.c:765 [inline]
 lookup_or_create_module_kobject+0xf3/0x1a0 kernel/params.c:749
 kernel_add_sysfs_param kernel/params.c:788 [inline]
 param_sysfs_builtin kernel/params.c:836 [inline]
 param_sysfs_builtin_init+0x298/0x3f0 kernel/params.c:972
 do_one_initcall+0x121/0x750 init/main.c:1392
 do_initcall_level init/main.c:1454 [inline]
 do_initcalls init/main.c:1470 [inline]
 do_basic_setup init/main.c:1490 [inline]
 kernel_init_freeable+0x6ea/0x7b0 init/main.c:1703
 kernel_init+0x1f/0x1e0 init/main.c:1593
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff888034075200
 which belongs to the cache kmalloc-16 of size 16
The buggy address is located 8 bytes inside of
 allocated 9-byte region [ffff888034075200, ffff888034075209)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888034075ac0 pfn:0x34075
flags: 0xfff00000000200(workingset|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000200 ffff88813fe30640 ffff88813fe2b408 ffffea00015f7850
raw: ffff888034075ac0 000000080080007f 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 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 23370513076, free_ts 23365043484
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1853
 prep_new_page mm/page_alloc.c:1861 [inline]
 get_page_from_freelist+0x11a6/0x3410 mm/page_alloc.c:3941
 __alloc_frozen_pages_noprof+0x27c/0x2bc0 mm/page_alloc.c:5221
 alloc_slab_page mm/slub.c:3278 [inline]
 allocate_slab mm/slub.c:3467 [inline]
 new_slab+0xa6/0x6c0 mm/slub.c:3525
 refill_objects+0x277/0x420 mm/slub.c:7272
 refill_sheaf mm/slub.c:2816 [inline]
 __pcs_replace_empty_main+0x375/0x650 mm/slub.c:4652
 alloc_from_pcs mm/slub.c:4750 [inline]
 slab_alloc_node mm/slub.c:4884 [inline]
 __do_kmalloc_node mm/slub.c:5295 [inline]
 __kmalloc_node_track_caller_noprof+0x694/0x850 mm/slub.c:5408
 __do_krealloc mm/slub.c:6711 [inline]
 krealloc_node_align_noprof+0x1f9/0x3e0 mm/slub.c:6770
 krealloc_array_noprof include/linux/slab.h:1128 [inline]
 add_sysfs_param+0x196/0x970 kernel/params.c:656
 kernel_add_sysfs_param kernel/params.c:797 [inline]
 param_sysfs_builtin kernel/params.c:836 [inline]
 param_sysfs_builtin_init+0x313/0x3f0 kernel/params.c:972
 do_one_initcall+0x121/0x750 init/main.c:1392
 do_initcall_level init/main.c:1454 [inline]
 do_initcalls init/main.c:1470 [inline]
 do_basic_setup init/main.c:1490 [inline]
 kernel_init_freeable+0x6ea/0x7b0 init/main.c:1703
 kernel_init+0x1f/0x1e0 init/main.c:1593
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
page last free pid 29 tgid 29 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1397 [inline]
 __free_frozen_pages+0x794/0x10a0 mm/page_alloc.c:2938
 vfree mm/vmalloc.c:3472 [inline]
 vfree+0x15f/0x8d0 mm/vmalloc.c:3436
 delayed_vfree_work+0x56/0x80 mm/vmalloc.c:3392
 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314
 process_scheduled_works kernel/workqueue.c:3397 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 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:
 ffff888034075100: 00 00 fc fc 00 00 fc fc 00 07 fc fc 00 07 fc fc
 ffff888034075180: 00 00 fc fc 00 02 fc fc 00 02 fc fc 00 00 fc fc
>ffff888034075200: 00 01 fc fc 00 01 fc fc 00 00 fc fc 00 00 fc fc
                      ^
 ffff888034075280: 00 00 fc fc 00 00 fc fc fa fb fc fc 00 05 fc fc
 ffff888034075300: 00 06 fc fc fa fb fc fc 00 04 fc fc 00 00 fc fc
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