kobject: 'loop1' (ffff8880a40a83e0): fill_kobj_path: path = '/devices/virtual/block/loop1'
kobject: 'loop1' (ffff8880a40a83e0): kobject_uevent_env
kobject: 'loop1' (ffff8880a40a83e0): fill_kobj_path: path = '/devices/virtual/block/loop1'
==================================================================
BUG: KASAN: use-after-free in memcpy include/linux/string.h:347 [inline]
BUG: KASAN: use-after-free in soft_cursor+0x43d/0xa50 drivers/video/fbdev/core/softcursor.c:70
Read of size 4 at addr ffff8880a1bf32cc by task syz-executor.2/17270

CPU: 0 PID: 17270 Comm: syz-executor.2 Not tainted 4.14.158-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: 0033:0x45a909
RSP: 002b:00007fce247fec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a909
RDX: 0000000020000080 RSI: 000000000000560a RDI: 0000000000000005
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fce247ff6d4
R13: 00000000004c7019 R14: 00000000004dd688 R15: 00000000ffffffff

Allocated by task 15263:
 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_node mm/slab.c:3682 [inline]
 __kmalloc_node_track_caller+0x51/0x80 mm/slab.c:3696
 __kmalloc_reserve.isra.0+0x40/0xe0 net/core/skbuff.c:137
 __alloc_skb+0xcf/0x500 net/core/skbuff.c:205
 alloc_skb include/linux/skbuff.h:980 [inline]
 kobject_uevent_env+0x781/0xc23 lib/kobject_uevent.c:479
 kobject_uevent+0x20/0x26 lib/kobject_uevent.c:553
 netdev_queue_add_kobject net/core/net-sysfs.c:1341 [inline]
 netdev_queue_update_kobjects+0x295/0x360 net/core/net-sysfs.c:1355
 register_queue_kobjects net/core/net-sysfs.c:1397 [inline]
 netdev_register_kobject+0x28a/0x3a0 net/core/net-sysfs.c:1603
 register_netdevice+0x814/0xca0 net/core/dev.c:7668
 bond_newlink drivers/net/bonding/bond_netlink.c:453 [inline]
 bond_newlink+0x41/0x80 drivers/net/bonding/bond_netlink.c:443
 rtnl_newlink+0xecb/0x1700 net/core/rtnetlink.c:2719
 rtnetlink_rcv_msg+0x3da/0xb70 net/core/rtnetlink.c:4306
 netlink_rcv_skb+0x14f/0x3c0 net/netlink/af_netlink.c:2432
 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:4318
 netlink_unicast_kernel net/netlink/af_netlink.c:1286 [inline]
 netlink_unicast+0x44d/0x650 net/netlink/af_netlink.c:1312
 netlink_sendmsg+0x7c4/0xc60 net/netlink/af_netlink.c:1877
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xce/0x110 net/socket.c:656
 ___sys_sendmsg+0x70a/0x840 net/socket.c:2062
 __sys_sendmsg+0xb9/0x140 net/socket.c:2096
 SYSC_sendmsg net/socket.c:2107 [inline]
 SyS_sendmsg+0x2d/0x50 net/socket.c:2103
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

Freed by task 15263:
 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]
 consume_skb+0xaf/0x340 net/core/skbuff.c:705
 netlink_broadcast_filtered+0x2ae/0x9e0 net/netlink/af_netlink.c:1488
 kobject_uevent_env+0x8da/0xc23 lib/kobject_uevent.c:495
 kobject_uevent+0x20/0x26 lib/kobject_uevent.c:553
 netdev_queue_add_kobject net/core/net-sysfs.c:1341 [inline]
 netdev_queue_update_kobjects+0x295/0x360 net/core/net-sysfs.c:1355
 register_queue_kobjects net/core/net-sysfs.c:1397 [inline]
 netdev_register_kobject+0x28a/0x3a0 net/core/net-sysfs.c:1603
 register_netdevice+0x814/0xca0 net/core/dev.c:7668
 bond_newlink drivers/net/bonding/bond_netlink.c:453 [inline]
 bond_newlink+0x41/0x80 drivers/net/bonding/bond_netlink.c:443
 rtnl_newlink+0xecb/0x1700 net/core/rtnetlink.c:2719
 rtnetlink_rcv_msg+0x3da/0xb70 net/core/rtnetlink.c:4306
 netlink_rcv_skb+0x14f/0x3c0 net/netlink/af_netlink.c:2432
 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:4318
 netlink_unicast_kernel net/netlink/af_netlink.c:1286 [inline]
 netlink_unicast+0x44d/0x650 net/netlink/af_netlink.c:1312
 netlink_sendmsg+0x7c4/0xc60 net/netlink/af_netlink.c:1877
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xce/0x110 net/socket.c:656
 ___sys_sendmsg+0x70a/0x840 net/socket.c:2062
 __sys_sendmsg+0xb9/0x140 net/socket.c:2096
 SYSC_sendmsg net/socket.c:2107 [inline]
 SyS_sendmsg+0x2d/0x50 net/socket.c:2103
 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 ffff8880a1bf32c0
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 12 bytes inside of
 512-byte region [ffff8880a1bf32c0, ffff8880a1bf34c0)
The buggy address belongs to the page:
page:ffffea000286fcc0 count:1 mapcount:0 mapping:ffff8880a1bf3040 index:0xffff8880a1bf3540
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffff8880a1bf3040 ffff8880a1bf3540 0000000100000002
raw: ffffea0002251060 ffffea000238ad20 ffff8880aa800940 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a1bf3180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880a1bf3200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880a1bf3280: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
                                              ^
 ffff8880a1bf3300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880a1bf3380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================