================================================================== BUG: KASAN: slab-out-of-bounds in fbcon_get_font+0x1de/0x910 drivers/video/fbdev/core/fbcon.c:2474 Read of size 5 at addr ffff888093c2220e by task syz-executor.3/12392 CPU: 0 PID: 12392 Comm: syz-executor.3 Not tainted 5.7.0-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+0x1e9/0x30e lib/dump_stack.c:118 print_address_description+0x66/0x5a0 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report+0x132/0x1d0 mm/kasan/report.c:530 check_memory_region_inline mm/kasan/generic.c:183 [inline] check_memory_region+0x2b5/0x2f0 mm/kasan/generic.c:192 memcpy+0x25/0x60 mm/kasan/common.c:105 fbcon_get_font+0x1de/0x910 drivers/video/fbdev/core/fbcon.c:2474 con_font_get drivers/tty/vt/vt.c:4479 [inline] con_font_op+0x664/0x1630 drivers/tty/vt/vt.c:4638 vt_ioctl+0x179d/0x3eb0 drivers/tty/vt/vt_ioctl.c:265 tty_ioctl+0xee4/0x15c0 drivers/tty/tty_io.c:2656 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl fs/ioctl.c:771 [inline] __do_sys_ioctl fs/ioctl.c:780 [inline] __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:778 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca69 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:00007f14b8c05c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e9d00 RCX: 000000000045ca69 RDX: 0000000020000640 RSI: 0000000000004b60 RDI: 0000000000000004 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000042c R14: 00000000004c6f3b R15: 00007f14b8c066d4 Allocated by task 10685: save_stack mm/kasan/common.c:48 [inline] set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc+0x103/0x140 mm/kasan/common.c:494 __do_kmalloc mm/slab.c:3656 [inline] __kmalloc+0x24b/0x330 mm/slab.c:3665 kmalloc include/linux/slab.h:560 [inline] fbcon_set_font+0x2c4/0x970 drivers/video/fbdev/core/fbcon.c:2672 con_font_set drivers/tty/vt/vt.c:4571 [inline] con_font_op+0xebc/0x1630 drivers/tty/vt/vt.c:4636 vt_ioctl+0x179d/0x3eb0 drivers/tty/vt/vt_ioctl.c:265 tty_ioctl+0xee4/0x15c0 drivers/tty/tty_io.c:2656 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl fs/ioctl.c:771 [inline] __do_sys_ioctl fs/ioctl.c:780 [inline] __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:778 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Freed by task 7395: save_stack mm/kasan/common.c:48 [inline] set_track mm/kasan/common.c:56 [inline] kasan_set_free_info mm/kasan/common.c:316 [inline] __kasan_slab_free+0x114/0x170 mm/kasan/common.c:455 __cache_free mm/slab.c:3426 [inline] kfree+0x10a/0x220 mm/slab.c:3757 skb_release_all net/core/skbuff.c:664 [inline] __kfree_skb+0x56/0x1c0 net/core/skbuff.c:678 tcp_rtx_queue_unlink_and_free include/net/tcp.h:1849 [inline] tcp_clean_rtx_queue net/ipv4/tcp_input.c:3151 [inline] tcp_ack+0x1fd3/0x66f0 net/ipv4/tcp_input.c:3678 tcp_rcv_established+0xc60/0x2040 net/ipv4/tcp_input.c:5652 tcp_v4_do_rcv+0x398/0x860 net/ipv4/tcp_ipv4.c:1629 tcp_v4_rcv+0x3c1c/0x49f0 net/ipv4/tcp_ipv4.c:2011 ip_protocol_deliver_rcu+0x390/0x750 net/ipv4/ip_input.c:204 ip_local_deliver_finish net/ipv4/ip_input.c:231 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] ip_local_deliver+0x311/0x490 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:441 [inline] ip_sublist_rcv_finish net/ipv4/ip_input.c:550 [inline] ip_list_rcv_finish net/ipv4/ip_input.c:600 [inline] ip_sublist_rcv+0xa0a/0xa60 net/ipv4/ip_input.c:608 ip_list_rcv+0x3af/0x3e0 net/ipv4/ip_input.c:643 __netif_receive_skb_list_ptype net/core/dev.c:5311 [inline] __netif_receive_skb_list_core+0x60b/0x7e0 net/core/dev.c:5359 __netif_receive_skb_list+0x482/0x530 net/core/dev.c:5411 netif_receive_skb_list_internal+0x44a/0x700 net/core/dev.c:5518 gro_normal_list net/core/dev.c:5629 [inline] napi_complete_done+0x2bc/0x770 net/core/dev.c:6354 virtqueue_napi_complete+0x28/0x90 drivers/net/virtio_net.c:329 virtnet_poll+0x947/0xc80 drivers/net/virtio_net.c:1455 napi_poll net/core/dev.c:6671 [inline] net_rx_action+0x62f/0x1140 net/core/dev.c:6739 __do_softirq+0x268/0x80c kernel/softirq.c:292 The buggy address belongs to the object at ffff888093c22000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 526 bytes inside of 1024-byte region [ffff888093c22000, ffff888093c22400) The buggy address belongs to the page: page:ffffea00024f0880 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea00025b2648 ffffea000242bd88 ffff8880aa400c40 raw: 0000000000000000 ffff888093c22000 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888093c22100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888093c22180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888093c22200: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888093c22280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888093c22300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================