================================================================== BUG: KASAN: use-after-free in memcpy include/linux/string.h:348 [inline] BUG: KASAN: use-after-free in soft_cursor+0x448/0xa20 drivers/video/fbdev/core/softcursor.c:70 Read of size 8 at addr ffff88809f9ace48 by task syz-executor.5/7025 CPU: 0 PID: 7025 Comm: syz-executor.5 Not tainted 4.19.120-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+0x188/0x20d lib/dump_stack.c:118 print_address_description.cold+0x7c/0x212 mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report mm/kasan/report.c:412 [inline] kasan_report.cold+0x88/0x2b9 mm/kasan/report.c:396 memcpy+0x20/0x50 mm/kasan/kasan.c:302 memcpy include/linux/string.h:348 [inline] soft_cursor+0x448/0xa20 drivers/video/fbdev/core/softcursor.c:70 bit_cursor+0x1230/0x1900 drivers/video/fbdev/core/bitblit.c:386 fbcon_cursor+0x572/0x760 drivers/video/fbdev/core/fbcon.c:1372 hide_cursor+0x85/0x2c0 drivers/tty/vt/vt.c:897 redraw_screen+0x2ed/0x870 drivers/tty/vt/vt.c:1001 vc_do_resize+0x108e/0x1380 drivers/tty/vt/vt.c:1312 vt_ioctl+0x1fa2/0x2500 drivers/tty/vt/vt_ioctl.c:901 tty_ioctl+0x7a1/0x1420 drivers/tty/tty_io.c:2669 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcda/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c829 Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fe9a6fb2c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004f28a0 RCX: 000000000045c829 RDX: 00000000200000c0 RSI: 000000000000560a RDI: 0000000000000005 RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000673 R14: 00000000004c9481 R15: 00007fe9a6fb36d4 Allocated by task 6573: set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc mm/kasan/kasan.c:553 [inline] kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:531 __do_kmalloc_node mm/slab.c:3689 [inline] __kmalloc_node_track_caller+0x4c/0x70 mm/slab.c:3703 __kmalloc_reserve.isra.0+0x39/0xe0 net/core/skbuff.c:137 __alloc_skb+0xef/0x5b0 net/core/skbuff.c:205 alloc_skb include/linux/skbuff.h:995 [inline] alloc_uevent_skb+0x7b/0x210 lib/kobject_uevent.c:288 uevent_net_broadcast_tagged lib/kobject_uevent.c:349 [inline] kobject_uevent_net_broadcast lib/kobject_uevent.c:409 [inline] kobject_uevent_env+0xe48/0x1160 lib/kobject_uevent.c:590 netdev_queue_add_kobject net/core/net-sysfs.c:1492 [inline] netdev_queue_update_kobjects+0x2ee/0x3c0 net/core/net-sysfs.c:1509 register_queue_kobjects net/core/net-sysfs.c:1551 [inline] netdev_register_kobject+0x29b/0x3b0 net/core/net-sysfs.c:1769 register_netdevice+0x7f7/0xf50 net/core/dev.c:8710 __ip_tunnel_create+0x349/0x510 net/ipv4/ip_tunnel.c:278 ip_tunnel_init_net+0x375/0x9e0 net/ipv4/ip_tunnel.c:1023 ops_init+0xaf/0x410 net/core/net_namespace.c:129 setup_net+0x2c2/0x6f0 net/core/net_namespace.c:315 copy_net_ns+0x1d9/0x331 net/core/net_namespace.c:438 create_new_namespaces+0x3fb/0x7c0 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xbd/0x1f0 kernel/nsproxy.c:206 ksys_unshare+0x439/0x8d0 kernel/fork.c:2530 __do_sys_unshare kernel/fork.c:2598 [inline] __se_sys_unshare kernel/fork.c:2596 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:2596 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 6573: set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0xf7/0x140 mm/kasan/kasan.c:521 __cache_free mm/slab.c:3503 [inline] kfree+0xce/0x220 mm/slab.c:3822 skb_free_head+0x91/0xb0 net/core/skbuff.c:554 skb_release_data+0x600/0x8c0 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 net/core/skbuff.c:705 [inline] consume_skb+0xda/0x380 net/core/skbuff.c:699 netlink_broadcast_filtered+0x314/0xb50 net/netlink/af_netlink.c:1520 netlink_broadcast+0x35/0x40 net/netlink/af_netlink.c:1542 uevent_net_broadcast_tagged lib/kobject_uevent.c:370 [inline] kobject_uevent_net_broadcast lib/kobject_uevent.c:409 [inline] kobject_uevent_env+0xf2f/0x1160 lib/kobject_uevent.c:590 netdev_queue_add_kobject net/core/net-sysfs.c:1492 [inline] netdev_queue_update_kobjects+0x2ee/0x3c0 net/core/net-sysfs.c:1509 register_queue_kobjects net/core/net-sysfs.c:1551 [inline] netdev_register_kobject+0x29b/0x3b0 net/core/net-sysfs.c:1769 register_netdevice+0x7f7/0xf50 net/core/dev.c:8710 __ip_tunnel_create+0x349/0x510 net/ipv4/ip_tunnel.c:278 ip_tunnel_init_net+0x375/0x9e0 net/ipv4/ip_tunnel.c:1023 ops_init+0xaf/0x410 net/core/net_namespace.c:129 setup_net+0x2c2/0x6f0 net/core/net_namespace.c:315 copy_net_ns+0x1d9/0x331 net/core/net_namespace.c:438 create_new_namespaces+0x3fb/0x7c0 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xbd/0x1f0 kernel/nsproxy.c:206 ksys_unshare+0x439/0x8d0 kernel/fork.c:2530 __do_sys_unshare kernel/fork.c:2598 [inline] __se_sys_unshare kernel/fork.c:2596 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:2596 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff88809f9acd40 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 264 bytes inside of 512-byte region [ffff88809f9acd40, ffff88809f9acf40) The buggy address belongs to the page: page:ffffea00027e6b00 count:1 mapcount:0 mapping:ffff88812c39c940 index:0x0 flags: 0xfffe0000000100(slab) raw: 00fffe0000000100 ffffea00029f23c8 ffffea0002a41888 ffff88812c39c940 raw: 0000000000000000 ffff88809f9ac0c0 0000000100000006 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88809f9acd00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff88809f9acd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88809f9ace00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88809f9ace80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88809f9acf00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ==================================================================