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BUG: KASAN: use-after-free in memcpy include/linux/string.h:406 [inline]
BUG: KASAN: use-after-free in soft_cursor+0x44b/0xa30 drivers/video/fbdev/core/softcursor.c:70
Read of size 6 at addr ffff88808f52e890 by task syz-executor.5/27232

CPU: 1 PID: 27232 Comm: syz-executor.5 Not tainted 5.8.0-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]
 soft_cursor+0x44b/0xa30 drivers/video/fbdev/core/softcursor.c:70
 bit_cursor+0x1166/0x17d0 drivers/video/fbdev/core/bitblit.c:386
 fbcon_cursor+0x537/0x660 drivers/video/fbdev/core/fbcon.c:1411
 hide_cursor+0x85/0x280 drivers/tty/vt/vt.c:906
 redraw_screen+0x5e3/0x770 drivers/tty/vt/vt.c:1011
 vc_do_resize+0xef0/0x1180 drivers/tty/vt/vt.c:1325
 vt_resizex drivers/tty/vt/vt_ioctl.c:814 [inline]
 vt_ioctl+0xeba/0x2c20 drivers/tty/vt/vt_ioctl.c:1026
 tty_ioctl+0x1019/0x15f0 drivers/tty/tty_io.c:2656
 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: 0033:0x45ce69
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:00007f620657cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000001c340 RCX: 000000000045ce69
RDX: 0000000020000000 RSI: 000000000000560a RDI: 0000000000000007
RBP: 000000000118c000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bfcc
R13: 00007ffe9673a99f R14: 00007f620657d9c0 R15: 000000000118bfcc

Allocated by task 1:
 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]
 __seq_open_private+0x20/0xd0 fs/seq_file.c:607
 seq_open_private+0x21/0x40 fs/seq_file.c:629
 mounts_open_common+0x260/0x670 fs/proc_namespace.c:271
 do_dentry_open+0x501/0x1290 fs/open.c:823
 do_open fs/namei.c:3243 [inline]
 path_openat+0x1b9a/0x2730 fs/namei.c:3360
 do_filp_open+0x17e/0x3c0 fs/namei.c:3387
 do_sys_openat2+0x16d/0x420 fs/open.c:1174
 do_sys_open fs/open.c:1190 [inline]
 __do_sys_open fs/open.c:1198 [inline]
 __se_sys_open fs/open.c:1194 [inline]
 __x64_sys_open+0x119/0x1c0 fs/open.c:1194
 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 ffff88808f52e800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 144 bytes inside of
 512-byte region [ffff88808f52e800, ffff88808f52ea00)
The buggy address belongs to the page:
page:000000001614cc9b refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x8f52e
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea0002760e88 ffffea00027ba3c8 ffff8880aa040600
raw: 0000000000000000 ffff88808f52e000 0000000100000004 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808f52e780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88808f52e800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88808f52e880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff88808f52e900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88808f52e980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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