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BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:347 [inline]
BUG: KASAN: slab-out-of-bounds in soft_cursor+0x43d/0xa50 drivers/video/fbdev/core/softcursor.c:70
Read of size 8 at addr ffff88808c7d8e10 by task syz-executor.4/29494

CPU: 1 PID: 29494 Comm: syz-executor.4 Not tainted 4.14.167-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+0x142/0x197 lib/dump_stack.c:58
 print_address_description.cold+0x7c/0x1dc 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+0xa9/0x2af mm/kasan/report.c:393
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x123/0x190 mm/kasan/kasan.c:267
 memcpy+0x24/0x50 mm/kasan/kasan.c:302
 memcpy include/linux/string.h:347 [inline]
 soft_cursor+0x43d/0xa50 drivers/video/fbdev/core/softcursor.c:70
 bit_cursor+0x11be/0x1830 drivers/video/fbdev/core/bitblit.c:386
 fbcon_cursor+0x4e3/0x6f0 drivers/video/fbdev/core/fbcon.c:1347
 hide_cursor+0x9d/0x2e0 drivers/tty/vt/vt.c:589
 redraw_screen+0x2a5/0x7c0 drivers/tty/vt/vt.c:679
 vc_do_resize+0xc8a/0xec0 drivers/tty/vt/vt.c:954
 vc_resize+0x4d/0x60 drivers/tty/vt/vt.c:974
 vt_ioctl+0x10a8/0x2170 drivers/tty/vt/vt_ioctl.c:901
 tty_ioctl+0x841/0x1320 drivers/tty/tty_io.c:2661
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x7ae/0x1060 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45b349
RSP: 002b:00007f73c7195c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f73c71966d4 RCX: 000000000045b349
RDX: 0000000020000080 RSI: 000000000000560a RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000647 R14: 00000000004c7d12 R15: 000000000075bf2c

Allocated by task 24966:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x45/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc mm/kasan/kasan.c:551 [inline]
 kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:529
 __do_kmalloc mm/slab.c:3720 [inline]
 __kmalloc+0x15d/0x7a0 mm/slab.c:3729
 kmalloc include/linux/slab.h:493 [inline]
 fbcon_set_font+0x2f8/0x7b0 drivers/video/fbdev/core/fbcon.c:2618
 con_font_set drivers/tty/vt/vt.c:4162 [inline]
 con_font_op+0xc0f/0x1060 drivers/tty/vt/vt.c:4227
 vt_ioctl+0xb80/0x2170 drivers/tty/vt/vt_ioctl.c:927
 tty_ioctl+0x841/0x1320 drivers/tty/tty_io.c:2661
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x7ae/0x1060 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

Freed by task 23968:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x45/0xd0 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+0xcc/0x270 mm/slab.c:3815
 skb_free_head+0x8b/0xb0 net/core/skbuff.c:554
 skb_release_data+0x543/0x7c0 net/core/skbuff.c:574
 skb_release_all+0x4d/0x60 net/core/skbuff.c:631
 __kfree_skb net/core/skbuff.c:645 [inline]
 kfree_skb+0xb5/0x350 net/core/skbuff.c:663
 sctp_ulpevent_free+0x238/0x320 net/sctp/ulpevent.c:1130
 sctp_ulpq_tail_event+0x5e2/0xa80 net/sctp/ulpqueue.c:278
 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1457 [inline]
 sctp_side_effects net/sctp/sm_sideeffect.c:1179 [inline]
 sctp_do_sm+0x22eb/0x50d0 net/sctp/sm_sideeffect.c:1150
 sctp_assoc_bh_rcv+0x2a0/0x5d0 net/sctp/associola.c:1096
 sctp_inq_push+0x1c9/0x260 net/sctp/inqueue.c:95
 sctp_backlog_rcv+0x116/0x860 net/sctp/input.c:350
 sk_backlog_rcv include/net/sock.h:917 [inline]
 __release_sock+0x12d/0x350 net/core/sock.c:2264
 release_sock+0x59/0x1b0 net/core/sock.c:2779
 sctp_connect net/sctp/socket.c:4183 [inline]
 sctp_inet_connect+0x13a/0x190 net/sctp/socket.c:4196
 SYSC_connect+0x1f6/0x2d0 net/socket.c:1655
 SyS_connect+0x24/0x30 net/socket.c:1636
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

The buggy address belongs to the object at ffff88808c7d8d00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 272 bytes inside of
 512-byte region [ffff88808c7d8d00, ffff88808c7d8f00)
The buggy address belongs to the page:
page:ffffea000231f600 count:1 mapcount:0 mapping:ffff88808c7d8080 index:0x0
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffff88808c7d8080 0000000000000000 0000000100000006
raw: ffffea0002172a20 ffffea0002560860 ffff8880aa800940 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808c7d8d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88808c7d8d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88808c7d8e00: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                         ^
 ffff88808c7d8e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88808c7d8f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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