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BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:406 [inline]
BUG: KASAN: slab-out-of-bounds in scr_memcpyw include/linux/vt_buffer.h:49 [inline]
BUG: KASAN: slab-out-of-bounds in vc_do_resize+0x9d8/0x1180 drivers/tty/vt/vt.c:1291
Read of size 4 at addr ffff88809367dd20 by task syz-executor.2/14404

CPU: 1 PID: 14404 Comm: syz-executor.2 Not tainted 5.8.0-rc7-next-20200731-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+0x18f/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
 check_memory_region_inline mm/kasan/generic.c:186 [inline]
 check_memory_region+0x13d/0x180 mm/kasan/generic.c:192
 memcpy+0x20/0x60 mm/kasan/common.c:105
 memcpy include/linux/string.h:406 [inline]
 scr_memcpyw include/linux/vt_buffer.h:49 [inline]
 vc_do_resize+0x9d8/0x1180 drivers/tty/vt/vt.c:1291
 fbcon_modechanged+0x36c/0x710 drivers/video/fbdev/core/fbcon.c:2990
 fbcon_update_vcs+0x3a/0x50 drivers/video/fbdev/core/fbcon.c:3048
 fb_set_var+0xae8/0xd60 drivers/video/fbdev/core/fbmem.c:1056
 do_fb_ioctl+0x33f/0x6c0 drivers/video/fbdev/core/fbmem.c:1109
 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1185
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl fs/ioctl.c:739 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45cc79
Code: 2d b6 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 fb b5 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f90fcd35c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000000d540 RCX: 000000000045cc79
RDX: 0000000020000200 RSI: 0000000000004601 RDI: 0000000000000003
RBP: 000000000078bf40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c
R13: 00007fff0a61abaf R14: 00007f90fcd369c0 R15: 000000000078bf0c

Allocated by task 14404:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461
 __do_kmalloc mm/slab.c:3655 [inline]
 __kmalloc+0x1a8/0x320 mm/slab.c:3664
 kmalloc include/linux/slab.h:559 [inline]
 kzalloc include/linux/slab.h:666 [inline]
 vc_do_resize+0x2f6/0x1180 drivers/tty/vt/vt.c:1228
 fbcon_modechanged+0x36c/0x710 drivers/video/fbdev/core/fbcon.c:2990
 fbcon_update_vcs+0x3a/0x50 drivers/video/fbdev/core/fbcon.c:3048
 fb_set_var+0xae8/0xd60 drivers/video/fbdev/core/fbmem.c:1056
 fbcon_resize+0x575/0x610 drivers/video/fbdev/core/fbcon.c:2231
 resize_screen drivers/tty/vt/vt.c:1175 [inline]
 vc_do_resize+0x535/0x1180 drivers/tty/vt/vt.c:1246
 fbcon_modechanged+0x36c/0x710 drivers/video/fbdev/core/fbcon.c:2990
 fbcon_update_vcs+0x3a/0x50 drivers/video/fbdev/core/fbcon.c:3048
 fb_set_var+0xae8/0xd60 drivers/video/fbdev/core/fbmem.c:1056
 do_fb_ioctl+0x33f/0x6c0 drivers/video/fbdev/core/fbmem.c:1109
 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1185
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl fs/ioctl.c:739 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff88809367dc00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 288 bytes inside of
 512-byte region [ffff88809367dc00, ffff88809367de00)
The buggy address belongs to the page:
page:00000000c2208310 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88809367d800 pfn:0x9367d
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea00029fe388 ffffea0002a2d248 ffff8880aa000600
raw: ffff88809367d800 ffff88809367d000 0000000100000003 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809367dc00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88809367dc80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88809367dd00: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
                               ^
 ffff88809367dd80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88809367de00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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