CVE-2026-90232 in Linux
摘要
由 VulDB • 2026-09-17
在 Linux 内核中，已修复以下漏洞：
amt：不支持跨网络命名空间（cross-netns）的设置。
当底层设备被注销时，`amt_device_event()` 会尝试注销其上层 AMT 设备，但存在两个问题：
1. `amt_lookup_upper_dev()` 仅在底层设备的网络命名空间内查找上层设备 2. `amt_device_event()` 仅注销单个上层设备
如果在另一个网络命名空间中的底层设备上创建 AMT 设备，移除该底层设备会触发以下崩溃（splat），并且直到所有上层设备被移除之前都会陷入停滞状态。[0]
考虑到第 1 点以及以下几点，跨网络命名空间的设置似乎是无意为之：
* `amt_link_setup()` 将 `dev->netns_immutable` 设置为 true * 快速路径中未调用 `skb_scrub_packet()` * iproute2 二进制文件无法通过 link-netns 找到跨网络命名空间的底层设备： # ip -n ns1 link add amt0 link-netns ns2 type amt dev veth1 Cannot find device "veth1"
与其支持它并准备针对每个网络命名空间（per-netns）的网络设备注销，不如禁止跨网络命名空间的设置。
请注意，问题 2 需要单独的修复方案。
[0]:
WARNING: net/core/dev.c:12518 at unregister_netdevice_many_notify+0x1cce/0x2250, CPU#48: ip/2031 Modules linked in: CPU: 48 UID: 0 PID: 2031 Comm: ip Not tainted 7.2.0-rc5+ #27 PREEMPT(full) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014 RIP: 0010:unregister_netdevice_many_notify (net/core/dev.c:12518) Code: 89 ef e8 d5 52 ae fe e9 d0 f4 ff ff 48 8d 3d f9 3b 9c 02 48 c7 c6 c0 0b 63 84 ba ab 1f 00 00 67 48 0f b9 3a e9 65 ff ff ff 90 <0f> 0b 90 eb 81 48 8d 3d f6 3b 9c 02 48 c7 c6 c0 0b 63 84 ba e2 1f RSP: 0018:ffffc90004abf160 EFLAGS: 00010212 RAX: ffff888104d38260 RBX: ffff88800b0911b8 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff85b9f880 RBP: ffffc90004abf2d0 R08: ffffffff85b9f887 R09: 1ffffffff0b73f10 R10: dffffc0000000000 R11: fffffbfff0b73f11 R12: ffff88800b091d08 R13: ffff88800b091178 R14: dffffc0000000000 R15: ffff88800b091000 FS: 00007f555b86c600(0000) GS:ffff8881942a0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000562107d489c0 CR3: 0000000109a40002 CR4: 0000000000372ef0 Call Trace: <TASK> rtnl_dellink (net/core/rtnetlink.c:3632 net/core/rtnetlink.c:3674) rtnetlink_rcv_msg (net/core/rtnetlink.c:7112) netlink_rcv_skb (net/netlink/af_netlink.c:2556) netlink_unicast (net/netlink/af_netlink.c:1319) netlink_sendmsg (net/netlink/af_netlink.c:1900) ____sys_sendmsg (net/socket.c:775) __sys_sendmsg (net/socket.c:2738) do_syscall_64 (arch/x86/entry/syscall_64.c:63) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) ... unregister_netdevice: waiting for veth0 to become free. Usage count = 7 ref_tracker: netdev@ffff88800d7496d8 has 3/3 users at __netdev_adjacent_dev_insert (./include/linux/netdevice.h:4525 ./include/linux/netdevice.h:4554 net/core/dev.c:8791) __netdev_upper_dev_link (net/core/dev.c:8879 net/core/dev.c:8963) netdev_upper_dev_link (net/core/dev.c:9009) amt_newlink (drivers/net/amt.c:3321)
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