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BUG: KASAN: use-after-free in memcpy include/linux/string.h:348 [inline]
BUG: KASAN: use-after-free in soft_cursor+0x448/0xa20 drivers/video/fbdev/core/softcursor.c:70
Read of size 16 at addr ffff88808921c7d0 by task syz-executor.3/20061

CPU: 0 PID: 20061 Comm: syz-executor.3 Not tainted 4.19.123-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x188/0x20d lib/dump_stack.c:118
 print_address_description.cold+0x7c/0x212 mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report mm/kasan/report.c:412 [inline]
 kasan_report.cold+0x88/0x2b9 mm/kasan/report.c:396
 memcpy+0x20/0x50 mm/kasan/kasan.c:302
 memcpy include/linux/string.h:348 [inline]
 soft_cursor+0x448/0xa20 drivers/video/fbdev/core/softcursor.c:70
 bit_cursor+0x1230/0x1900 drivers/video/fbdev/core/bitblit.c:386
 fbcon_cursor+0x572/0x760 drivers/video/fbdev/core/fbcon.c:1372
 hide_cursor+0x85/0x2c0 drivers/tty/vt/vt.c:902
 redraw_screen+0x2ed/0x870 drivers/tty/vt/vt.c:1006
 vc_do_resize+0x108e/0x1380 drivers/tty/vt/vt.c:1317
 vt_ioctl+0x1fa2/0x2500 drivers/tty/vt/vt_ioctl.c:901
 tty_ioctl+0x7a1/0x1420 drivers/tty/tty_io.c:2669
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xcda/0x12e0 fs/ioctl.c:688
 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45ca29
Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f35468ffc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004f2b00 RCX: 000000000045ca29
RDX: 0000000020000000 RSI: 000000000000560a RDI: 0000000000000003
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000673 R14: 00000000004c9681 R15: 00007f35469006d4

Allocated by task 19967:
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc mm/kasan/kasan.c:553 [inline]
 kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:531
 kmem_cache_alloc_trace+0x14d/0x7a0 mm/slab.c:3625
 kmalloc include/linux/slab.h:515 [inline]
 kzalloc include/linux/slab.h:709 [inline]
 ep_alloc fs/eventpoll.c:1021 [inline]
 do_epoll_create+0xcd/0x380 fs/eventpoll.c:1960
 __do_sys_epoll_create1 fs/eventpoll.c:1991 [inline]
 __se_sys_epoll_create1 fs/eventpoll.c:1989 [inline]
 __x64_sys_epoll_create1+0x2d/0x40 fs/eventpoll.c:1989
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 19967:
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0xf7/0x140 mm/kasan/kasan.c:521
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xce/0x220 mm/slab.c:3822
 ep_eventpoll_release+0x41/0x60 fs/eventpoll.c:869
 __fput+0x2cd/0x890 fs/file_table.c:278
 task_work_run+0x13f/0x1b0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0xbcd/0x2f30 kernel/exit.c:880
 do_group_exit+0x125/0x350 kernel/exit.c:983
 __do_sys_exit_group kernel/exit.c:994 [inline]
 __se_sys_exit_group kernel/exit.c:992 [inline]
 __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:992
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff88808921c780
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 80 bytes inside of
 512-byte region [ffff88808921c780, ffff88808921c980)
The buggy address belongs to the page:
page:ffffea0002248700 count:1 mapcount:0 mapping:ffff88812c39c940 index:0x0
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffffea0002930e48 ffffea0002246cc8 ffff88812c39c940
raw: 0000000000000000 ffff88808921c000 0000000100000006 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808921c680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88808921c700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88808921c780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                 ^
 ffff88808921c800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88808921c880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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