Linux/Unix 主机中安装的一个或多个程序包受到一个漏洞影响，而供应商没有提供补丁程序。

  - net：netlink：af_netlink：通过在 len 上添加检查防止空 skb。添加对 len 参数的检查以避免空 skb。这可防止 netem_enqueue 函数中如下所示在随机化损坏步骤中的 skb->len=0 且 skb->data_len=0 时导致。 skb->data[prandom_u32() % skb_headlen(skb)] ^= 1<<(prandom_u32() % 8);崩溃报告[ 343.170349] netdevsim netdevsim0 netdevsim3
    set [1, 0] 类型 2 系列 0 端口 6081 - 0 [ 343.216110] netem: 版本 1.3 [ 343.235841] 除法错误0000 [#1] PREEMPT SMP KASAN NOPTI [ 343.236680] CPU: 3 PID: 4288 Comm repeater Not tainted 5.16.0-rc1+ [343.237569] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014 [343.238707] RIP: 0010:netem_enqueue+ 0x1590/0x33c0 [sch_netem] [ 343.239499] 代码89 85 58 ff ff ff e8 5f 5d e9 d3 48 8b b5 48 ff ff ff 8b 8d 50 ff ff ff 8b 85 58 ff ff ff 48 8b bd 70 ff ff ff 31 d2 2b 4f 74 <f7> f1 48 b8 00 00 00 00 00 fc ff df 49 01 d5 4c 89 e9 48 c1 e9 03 [ 343.241883] RSP: 0018:ffff88800bcd7368 EFLAGS: 00010246 [ 343.242589] RAX: 00000000ba7c0a9c RBX: 0000000000000001 RCX 0000000000000000 [343.243542] RDX: 0000000000000000 RSI: ffff88800f8edb10 RDI: ffff88800f8eda40 [ 343.244474] RBP
    ffff88800bcd7458 R080000000000000000 R09ffffffff94fb8445 [ 343.245403] R10ffffffff94fb8336 R11
    ffffffff94fb8445 R120000000000000000 [ 343.246355] R13ffff88800a5a7000 R14ffff88800a5b5800 R15
    0000000000000020 [ 343.247291] FS: 00007fdde2bd7700(0000) GS:ffff888109780000(0000) knlGS:0000000000000000 [ 343.248350] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 343.249120] CR2: 00000000200000c0 CR3:
    000000000ef4c000 CR4: 00000000000006e0 [ 343.250076] 调用跟踪[ 343.250423] <TASK> [ 343.250713] ? memcpy+0x4d/0x60 [ 343.251162] ? netem_init+0xa0/0xa0 [sch_netem] [ 343.251795] ?
    __sanitizer_cov_trace_pc+0x21/0x60 [ 343.252443] netem_enqueue+0xe28/0x33c0 [sch_netem] [ 343.253102] ? stack_trace_save+0x87/0xb0 [ 343.253655] ? filter_irq_stacks+0xb0/0xb0 [ 343.254220] netem_init+0xa0/0xa0 [sch_netem] [ 343.254837] ? __kasan_check_write+0x14/0x20 [ 343.255418] ?
    _raw_spin_lock+0x88/0xd6 [ 343.255953] dev_qdisc_enqueue+0x50/0x180 [ 343.256508]
    __dev_queue_xmit+0x1a7e/0x3090 [ 343.257083] netdev_core_pick_tx+0x300/0x300 [ 343.257690] ? check_kcov_mode+0x10/0x40 [ 343.258219] ? _raw_spin_unlock_irqrestore+0x29/0x40 [ 343.258899] ?
    __kasan_init_slab_obj+0x24/0x30 [ 343.259529] ? setup_object.isra.71+0x23/0x90 [ 343.260121] new_slab+0x26e/0x4b0 [ 343.260609] kasan_poison+0x3a/0x50 [ 343.261118] ? kasan_unpoison+0x28/0x50 [343.261637] ? __kasan_slab_alloc+0x71/0x90 [ 343.262214] memcpy+0x4d/0x60 [ 343.262674] ? write_comp_data+0x2f/0x90 [ 343.263209] ? __kasan_check_write+0x14/0x20 [ 343.263802] ?
    __skb_clone+0x5d6/0x840 [ 343.264329] ? __sanitizer_cov_trace_pc+0x21/0x60 [ 343.264958] dev_queue_xmit+0x1c/0x20 [ 343.265470] netlink_deliver_tap+0x652/0x9c0 [ 343.266067] netlink_unicast+0x5a0/0x7f0 [ 343.266608] ? netlink_attachskb+0x860/0x860 [ 343.267183] ?
    __sanitizer_cov_trace_pc+0x21/0x60 [ 343.267820] write_comp_data+0x2f/0x90 [ 343.268367] netlink_sendmsg+0x922/0xe80 [ 343.268899] ? netlink_unicast+0x7f0/0x7f0 [ 343.269472]
    __sanitizer_cov_trace_pc+0x21/0x60 [ 343.270099] write_comp_data+0x2f/0x90 [ 343.270644] ? netlink_unicast+0x7f0/0x7f0 [ 343.271210] sock_sendmsg+0x155/0x190 [ 343.271721]
    ____sys_sendmsg+0x75f/0x8f0 [ 343.272262] ? kernel_sendmsg+0x60/0x60 [ 343.272788] ? write_comp_data+0x2f/0x90 [ 343.273332] ? write_comp_data+0x2f/0x90 [ 343.273869]
    ___sys_sendmsg+0x10f/0x190 [ 343.274405] sendmsg_copy_msghdr+0x80/0x80 [ 343.274984] ? slab_post_alloc_hook+0x70/0x230 [ 343.275597] ? futex_wait_setup+0x240/0x240 [ 343.276175] ? security_file_alloc+0x3e/0x170 [ 343.276779] ? write_comp_d ---truncated--- (CVE-2021-47606)

请注意，Nessus 依赖供应商报告的程序包是否存在进行判断。

检测

Linux Distros 未修补的漏洞：CVE-2021-47606

medium Nessus 插件 ID 224436

版本 1.15