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BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:347 [inline]
BUG: KASAN: slab-out-of-bounds in soft_cursor+0x43d/0xa50 drivers/video/fbdev/core/softcursor.c:70
Read of size 2 at addr ffff888097c7ee0e by task kworker/0:3/7312

CPU: 0 PID: 7312 Comm: kworker/0:3 Not tainted 4.14.169-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_power_efficient fb_flashcursor
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x142/0x197 lib/dump_stack.c:58
 print_address_description.cold+0x7c/0x1dc mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0xa9/0x2af mm/kasan/report.c:393
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x123/0x190 mm/kasan/kasan.c:267
 memcpy+0x24/0x50 mm/kasan/kasan.c:302
 memcpy include/linux/string.h:347 [inline]
 soft_cursor+0x43d/0xa50 drivers/video/fbdev/core/softcursor.c:70
 bit_cursor+0x11be/0x1830 drivers/video/fbdev/core/bitblit.c:386
 fb_flashcursor+0x36d/0x410 drivers/video/fbdev/core/fbcon.c:393
 process_one_work+0x863/0x1600 kernel/workqueue.c:2114
 worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248
 kthread+0x319/0x430 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404

Allocated by task 10539:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x45/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc mm/kasan/kasan.c:551 [inline]
 kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:529
 __do_kmalloc mm/slab.c:3720 [inline]
 __kmalloc+0x15d/0x7a0 mm/slab.c:3729
 kmalloc include/linux/slab.h:493 [inline]
 fbcon_set_font+0x2f8/0x7b0 drivers/video/fbdev/core/fbcon.c:2618
 con_font_set drivers/tty/vt/vt.c:4162 [inline]
 con_font_op+0xc0f/0x1060 drivers/tty/vt/vt.c:4227
 vt_ioctl+0xb80/0x2170 drivers/tty/vt/vt_ioctl.c:927
 tty_ioctl+0x841/0x1320 drivers/tty/tty_io.c:2661
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x7ae/0x1060 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

Freed by task 8643:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x45/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x75/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kfree+0xcc/0x270 mm/slab.c:3815
 ep_free+0x1cd/0x220 fs/eventpoll.c:870
 ep_eventpoll_release+0x46/0x60 fs/eventpoll.c:878
 __fput+0x275/0x7a0 fs/file_table.c:210
 ____fput+0x16/0x20 fs/file_table.c:244
 task_work_run+0x114/0x190 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x1da/0x220 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4bc/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

The buggy address belongs to the object at ffff888097c7ecc0
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 334 bytes inside of
 512-byte region [ffff888097c7ecc0, ffff888097c7eec0)
The buggy address belongs to the page:
page:ffffea00025f1f80 count:1 mapcount:0 mapping:ffff888097c7e040 index:0x0
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffff888097c7e040 0000000000000000 0000000100000006
raw: ffffea0002655c20 ffffea00023d7860 ffff8880aa800940 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888097c7ed00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888097c7ed80: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
>ffff888097c7ee00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                      ^
 ffff888097c7ee80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888097c7ef00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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