================================================================== BUG: KASAN: use-after-free in __fb_pad_aligned_buffer include/linux/fb.h:674 [inline] BUG: KASAN: use-after-free in bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline] BUG: KASAN: use-after-free in bit_putcs+0xc74/0xe10 drivers/video/fbdev/core/bitblit.c:185 Read of size 1 at addr ffff88809571978c by task syz-executor.5/29520 CPU: 0 PID: 29520 Comm: syz-executor.5 Not tainted 4.19.121-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 __fb_pad_aligned_buffer include/linux/fb.h:674 [inline] bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline] bit_putcs+0xc74/0xe10 drivers/video/fbdev/core/bitblit.c:185 fbcon_putcs+0x434/0x4f0 drivers/video/fbdev/core/fbcon.c:1323 con_flush drivers/tty/vt/vt.c:2547 [inline] do_con_write.part.0+0xe40/0x1db0 drivers/tty/vt/vt.c:2800 do_con_write drivers/tty/vt/vt.c:2566 [inline] con_write+0x41/0xe0 drivers/tty/vt/vt.c:3133 process_output_block drivers/tty/n_tty.c:593 [inline] n_tty_write+0x3ee/0x1080 drivers/tty/n_tty.c:2331 do_tty_write drivers/tty/tty_io.c:960 [inline] tty_write+0x452/0x790 drivers/tty/tty_io.c:1044 do_loop_readv_writev fs/read_write.c:704 [inline] do_loop_readv_writev fs/read_write.c:688 [inline] do_iter_write fs/read_write.c:962 [inline] do_iter_write+0x460/0x5e0 fs/read_write.c:941 vfs_writev+0x1b3/0x2f0 fs/read_write.c:1005 do_writev+0x136/0x330 fs/read_write.c:1040 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:00007f03e632bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 000000000050d3e0 RCX: 000000000045c829 RDX: 0000000000000001 RSI: 00000000200005c0 RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000d20 R14: 00000000004cb269 R15: 00007f03e632c6d4 Allocated by task 26905: 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 rx_queue_add_kobject net/core/net-sysfs.c:948 [inline] net_rx_queue_update_kobjects+0xf2/0x450 net/core/net-sysfs.c:970 register_queue_kobjects net/core/net-sysfs.c:1546 [inline] netdev_register_kobject+0x278/0x3b0 net/core/net-sysfs.c:1769 register_netdevice+0x7f7/0xf50 net/core/dev.c:8710 ieee80211_if_add+0xfdb/0x1920 net/mac80211/iface.c:1888 ieee80211_register_hw+0x2bf4/0x34e0 net/mac80211/main.c:1160 mac80211_hwsim_new_radio+0x1cb9/0x3bb0 drivers/net/wireless/mac80211_hwsim.c:2896 hwsim_new_radio_nl+0x5df/0x86c drivers/net/wireless/mac80211_hwsim.c:3374 genl_family_rcv_msg+0x627/0xc10 net/netlink/genetlink.c:602 genl_rcv_msg+0xbf/0x160 net/netlink/genetlink.c:627 netlink_rcv_skb+0x160/0x410 net/netlink/af_netlink.c:2455 genl_rcv+0x24/0x40 net/netlink/genetlink.c:638 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x4d7/0x6a0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x80b/0xcd0 net/netlink/af_netlink.c:1909 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:632 ___sys_sendmsg+0x803/0x920 net/socket.c:2115 __sys_sendmsg+0xec/0x1b0 net/socket.c:2153 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 26905: 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 rx_queue_add_kobject net/core/net-sysfs.c:948 [inline] net_rx_queue_update_kobjects+0xf2/0x450 net/core/net-sysfs.c:970 register_queue_kobjects net/core/net-sysfs.c:1546 [inline] netdev_register_kobject+0x278/0x3b0 net/core/net-sysfs.c:1769 register_netdevice+0x7f7/0xf50 net/core/dev.c:8710 ieee80211_if_add+0xfdb/0x1920 net/mac80211/iface.c:1888 ieee80211_register_hw+0x2bf4/0x34e0 net/mac80211/main.c:1160 mac80211_hwsim_new_radio+0x1cb9/0x3bb0 drivers/net/wireless/mac80211_hwsim.c:2896 hwsim_new_radio_nl+0x5df/0x86c drivers/net/wireless/mac80211_hwsim.c:3374 genl_family_rcv_msg+0x627/0xc10 net/netlink/genetlink.c:602 genl_rcv_msg+0xbf/0x160 net/netlink/genetlink.c:627 netlink_rcv_skb+0x160/0x410 net/netlink/af_netlink.c:2455 genl_rcv+0x24/0x40 net/netlink/genetlink.c:638 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x4d7/0x6a0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x80b/0xcd0 net/netlink/af_netlink.c:1909 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:632 ___sys_sendmsg+0x803/0x920 net/socket.c:2115 __sys_sendmsg+0xec/0x1b0 net/socket.c:2153 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 ffff888095719780 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 12 bytes inside of 512-byte region [ffff888095719780, ffff888095719980) The buggy address belongs to the page: page:ffffea000255c640 count:1 mapcount:0 mapping:ffff88812c39c940 index:0xffff888095719000 flags: 0xfffe0000000100(slab) raw: 00fffe0000000100 ffffea000211d608 ffffea000228d208 ffff88812c39c940 raw: ffff888095719000 ffff888095719000 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888095719680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888095719700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888095719780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888095719800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888095719880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================