audit: type=1804 audit(1583927171.251:195): pid=15851 uid=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 op="invalid_pcr" cause="open_writers" comm="syz-executor.4" name="/root/syzkaller-testdir108466871/syzkaller.kEOPuv/330/bus" dev="sda1" ino=17602 res=1
==================================================================
BUG: KASAN: use-after-free in memcpy include/linux/string.h:347 [inline]
BUG: KASAN: use-after-free in soft_cursor+0x445/0xa40 drivers/video/fbdev/core/softcursor.c:70
Read of size 7 at addr ffff88809a5d95d9 by task syz-executor.2/15845

CPU: 0 PID: 15845 Comm: syz-executor.2 Not tainted 4.14.172-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:1347
 hide_cursor+0x96/0x2d0 drivers/tty/vt/vt.c:589
 redraw_screen+0x2a1/0x770 drivers/tty/vt/vt.c:679
 vc_do_resize+0xbf8/0xe10 drivers/tty/vt/vt.c:954
 vt_ioctl+0x1a08/0x1f00 drivers/tty/vt/vt_ioctl.c:891
 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: 0033:0x45c6c9
RSP: 002b:00007fe944f7ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fe944f7f6d4 RCX: 000000000045c6c9
RDX: 00000000200002c0 RSI: 000000000000560a RDI: 0000000000000003
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000066b R14: 00000000004c926c R15: 000000000076bf2c

Allocated by task 14668:
 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_node mm/slab.c:3682 [inline]
 __kmalloc_node_track_caller+0x4c/0x70 mm/slab.c:3696
 __kmalloc_reserve.isra.0+0x35/0xd0 net/core/skbuff.c:137
 __alloc_skb+0xca/0x4c0 net/core/skbuff.c:205
 alloc_skb include/linux/skbuff.h:980 [inline]
 alloc_skb_with_frags+0x85/0x4f0 net/core/skbuff.c:5228
 sock_alloc_send_pskb+0x586/0x6d0 net/core/sock.c:2078
 unix_stream_sendmsg+0x502/0x820 net/unix/af_unix.c:1902
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xc5/0x100 net/socket.c:656
 ___sys_sendmsg+0x70a/0x840 net/socket.c:2062
 __sys_sendmsg+0xa3/0x120 net/socket.c:2096
 SYSC_sendmsg net/socket.c:2107 [inline]
 SyS_sendmsg+0x27/0x40 net/socket.c:2103
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

Freed by task 7285:
 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
 skb_release_all+0x46/0x60 net/core/skbuff.c:631
 __kfree_skb net/core/skbuff.c:645 [inline]
 consume_skb+0xa7/0x330 net/core/skbuff.c:705
 unix_stream_read_generic+0x1463/0x1920 net/unix/af_unix.c:2433
 unix_stream_recvmsg+0x9b/0xc0 net/unix/af_unix.c:2491
 sock_recvmsg_nosec net/socket.c:819 [inline]
 sock_recvmsg net/socket.c:826 [inline]
 sock_recvmsg+0xc0/0x100 net/socket.c:822
 sock_read_iter+0x252/0x360 net/socket.c:903
 call_read_iter include/linux/fs.h:1771 [inline]
 do_iter_readv_writev+0x4a0/0x600 fs/read_write.c:673
 do_iter_read+0x217/0x5a0 fs/read_write.c:917
 vfs_readv+0xd3/0x130 fs/read_write.c:981
 do_readv+0xfc/0x2c0 fs/read_write.c:1014
 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 ffff88809a5d9540
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 153 bytes inside of
 512-byte region [ffff88809a5d9540, ffff88809a5d9740)
The buggy address belongs to the page:
page:ffffea0002697640 count:1 mapcount:0 mapping:ffff88809a5d9040 index:0xffff88809a5d9540
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffff88809a5d9040 ffff88809a5d9540 0000000100000005
raw: ffffea0002634ea0 ffffea0002172920 ffff88812fe56940 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809a5d9480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88809a5d9500: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
>ffff88809a5d9580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                    ^
 ffff88809a5d9600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88809a5d9680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================