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BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:426 [inline]
BUG: KASAN: slab-out-of-bounds in soft_cursor+0x439/0xa30 drivers/video/fbdev/core/softcursor.c:70
Read of size 16 at addr ffff8880a05ac740 by task syz-executor746/9794

CPU: 1 PID: 9794 Comm: syz-executor746 Not tainted 5.5.0-rc5-next-20200110-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+0x197/0x210 lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374
 __kasan_report.cold+0x1b/0x32 mm/kasan/report.c:506
 kasan_report+0x12/0x20 mm/kasan/common.c:641
 check_memory_region_inline mm/kasan/generic.c:185 [inline]
 check_memory_region+0x134/0x1a0 mm/kasan/generic.c:192
 memcpy+0x24/0x50 mm/kasan/common.c:127
 memcpy include/linux/string.h:426 [inline]
 soft_cursor+0x439/0xa30 drivers/video/fbdev/core/softcursor.c:70
 bit_cursor+0x12fc/0x1a60 drivers/video/fbdev/core/bitblit.c:386
 fbcon_cursor+0x487/0x660 drivers/video/fbdev/core/fbcon.c:1409
 hide_cursor+0x9d/0x2b0 drivers/tty/vt/vt.c:895
 redraw_screen+0x60b/0x7d0 drivers/tty/vt/vt.c:988
 vc_do_resize+0x10c9/0x1460 drivers/tty/vt/vt.c:1284
 vc_resize+0x4d/0x60 drivers/tty/vt/vt.c:1304
 vt_ioctl+0x2076/0x26d0 drivers/tty/vt/vt_ioctl.c:887
 tty_ioctl+0xa37/0x14f0 drivers/tty/tty_io.c:2660
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x123/0x180 fs/ioctl.c:760
 __do_sys_ioctl fs/ioctl.c:769 [inline]
 __se_sys_ioctl fs/ioctl.c:767 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:767
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x440249
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 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 5b 14 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffe0c9539d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440249
RDX: 0000000020000000 RSI: 000000000000560a RDI: 0000000000000004
RBP: 00000000006cb018 R08: 000000000000000d R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401b30
R13: 0000000000401bc0 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 9794:
 save_stack+0x23/0x90 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 __kasan_kmalloc mm/kasan/common.c:515 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:488
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:529
 __do_kmalloc mm/slab.c:3656 [inline]
 __kmalloc+0x163/0x770 mm/slab.c:3665
 kmalloc include/linux/slab.h:560 [inline]
 fbcon_set_font+0x32d/0x860 drivers/video/fbdev/core/fbcon.c:2670
 con_font_set drivers/tty/vt/vt.c:4538 [inline]
 con_font_op+0xe30/0x1270 drivers/tty/vt/vt.c:4603
 do_fontx_ioctl drivers/tty/vt/vt_ioctl.c:244 [inline]
 vt_ioctl+0x35a/0x26d0 drivers/tty/vt/vt_ioctl.c:930
 tty_ioctl+0xa37/0x14f0 drivers/tty/tty_io.c:2660
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x123/0x180 fs/ioctl.c:760
 __do_sys_ioctl fs/ioctl.c:769 [inline]
 __se_sys_ioctl fs/ioctl.c:767 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:767
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 9523:
 save_stack+0x23/0x90 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 kasan_set_free_info mm/kasan/common.c:337 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:476
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:485
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x10a/0x2c0 mm/slab.c:3757
 sk_prot_free net/core/sock.c:1640 [inline]
 __sk_destruct+0x5d8/0x7f0 net/core/sock.c:1724
 sk_destruct+0xd5/0x110 net/core/sock.c:1739
 __sk_free+0xfb/0x360 net/core/sock.c:1750
 sk_free+0x83/0xb0 net/core/sock.c:1761
 deferred_put_nlk_sk+0x163/0x300 net/netlink/af_netlink.c:729
 rcu_do_batch kernel/rcu/tree.c:2206 [inline]
 rcu_core+0x5e3/0x1440 kernel/rcu/tree.c:2433
 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2442
 __do_softirq+0x262/0x98c kernel/softirq.c:292

The buggy address belongs to the object at ffff8880a05ac000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1856 bytes inside of
 2048-byte region [ffff8880a05ac000, ffff8880a05ac800)
The buggy address belongs to the page:
page:ffffea0002816b00 refcount:1 mapcount:0 mapping:ffff8880aa400e00 index:0x0
raw: 00fffe0000000200 ffffea000292c088 ffffea0002a4e0c8 ffff8880aa400e00
raw: 0000000000000000 ffff8880a05ac000 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a05ac600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880a05ac680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880a05ac700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                           ^
 ffff8880a05ac780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880a05ac800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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