audit: type=1804 audit(1589413647.295:35347): pid=14226 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op="invalid_pcr" cause="ToMToU" comm="syz-executor.1" name="/root/syzkaller-testdir222037023/syzkaller.uHUPmu/176/bus" dev="sda1" ino=16545 res=1
==================================================================
BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:347 [inline]
BUG: KASAN: slab-out-of-bounds in soft_cursor+0x445/0xa40 drivers/video/fbdev/core/softcursor.c:70
Read of size 8 at addr ffff88808d385190 by task syz-executor.2/14220

CPU: 0 PID: 14220 Comm: syz-executor.2 Not tainted 4.14.180-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x13e/0x194 lib/dump_stack.c:58
 print_address_description.cold+0x7c/0x1e2 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+0xa9/0x2ae mm/kasan/report.c:393
 memcpy+0x20/0x50 mm/kasan/kasan.c:302
 memcpy include/linux/string.h:347 [inline]
 soft_cursor+0x445/0xa40 drivers/video/fbdev/core/softcursor.c:70
 bit_cursor+0x10d9/0x1700 drivers/video/fbdev/core/bitblit.c:386
 fbcon_cursor+0x4be/0x690 drivers/video/fbdev/core/fbcon.c:1350
 hide_cursor+0x7a/0x2a0 drivers/tty/vt/vt.c:590
 redraw_screen+0x2a1/0x770 drivers/tty/vt/vt.c:680
 vc_do_resize+0xbe0/0xde0 drivers/tty/vt/vt.c:967
 vt_ioctl+0x1a64/0x1f20 drivers/tty/vt/vt_ioctl.c:901
 tty_ioctl+0x6c5/0x1220 drivers/tty/tty_io.c:2661
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c829
RSP: 002b:00007f1b3d480c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004f28a0 RCX: 000000000045c829
RDX: 00000000200000c0 RSI: 000000000000560a RDI: 0000000000000005
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000673 R14: 00000000004c9481 R15: 00007f1b3d4816d4

Allocated by task 10182:
 save_stack+0x32/0xa0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc mm/kasan/kasan.c:551 [inline]
 kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:529
 __do_kmalloc mm/slab.c:3720 [inline]
 __kmalloc+0x15b/0x7c0 mm/slab.c:3729
 kmalloc include/linux/slab.h:493 [inline]
 fbcon_set_font+0x2f8/0x7c0 drivers/video/fbdev/core/fbcon.c:2621
 con_font_set drivers/tty/vt/vt.c:4182 [inline]
 con_font_op+0xb73/0xf70 drivers/tty/vt/vt.c:4247
 vt_ioctl+0x736/0x1f20 drivers/tty/vt/vt_ioctl.c:928
 tty_ioctl+0x6c5/0x1220 drivers/tty/tty_io.c:2661
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

Freed by task 9045:
 save_stack+0x32/0xa0 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+0xcb/0x260 mm/slab.c:3815
 skb_free_head+0x83/0xa0 net/core/skbuff.c:554
 skb_release_data+0x528/0x7b0 net/core/skbuff.c:574
 __consume_stateless_skb+0x4f/0x2b0 net/core/skbuff.c:719
 skb_consume_udp net/ipv4/udp.c:1426 [inline]
 skb_consume_udp+0xfc/0x240 net/ipv4/udp.c:1409
 udpv6_recvmsg+0xf45/0x1750 net/ipv6/udp.c:468
 inet_recvmsg+0xef/0x4c0 net/ipv4/af_inet.c:793
 ___sys_recvmsg+0x21f/0x4d0 net/socket.c:2221
 __sys_recvmmsg+0x1f3/0x620 net/socket.c:2329
 SYSC_recvmmsg net/socket.c:2405 [inline]
 SyS_recvmmsg+0x125/0x140 net/socket.c:2394
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

The buggy address belongs to the object at ffff88808d385080
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 272 bytes inside of
 512-byte region [ffff88808d385080, ffff88808d385280)
The buggy address belongs to the page:
page:ffffea000234e140 count:1 mapcount:0 mapping:ffff88808d385080 index:0xffff88808d385580
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffff88808d385080 ffff88808d385580 0000000100000005
raw: ffffea00025ca360 ffffea00023273a0 ffff88812fe54940 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808d385080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88808d385100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88808d385180: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                         ^
 ffff88808d385200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88808d385280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================