In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
vxlan: initialize _md in vxlan_xmit_one()<\/p>\n
If a VXLAN device is configured with both VXLAN_F_COLLECT_METADATA and
\nVXLAN_F_GBP, and a packet is transmitted through it using an external
\nip_tunnel_info that lacks the IP_TUNNEL_VXLAN_OPT_BIT flag, md is left
\npointing to the uninitialized _md stack variable:<\/p>\n
if (test_bit(IP_TUNNEL_VXLAN_OPT_BIT, info->key.tun_flags)) {
\n if (info->options_len gbp is read:<\/p>\n
if (!md->gbp)
\n return;
\n gbp = (struct vxlanhdr_gbp *)vxh;
\n …
\n if (md->gbp & VXLAN_GBP_DONT_LEARN)
\n gbp->dont_learn = 1;<\/p>\n
If the stack contains garbage, this causes:
\n1) VXLAN_HF_GBP flag to be spuriously set in the VXLAN header.
\n2) gbp->dont_learn and gbp->policy_applied to be set from stack bits.
\n3) gbp->policy_id to receive 16 bits of uninitialized kernel stack data,
\n leaking it onto the wire.<\/p>\n
Fix this by zero-initializing _md. If IP_TUNNEL_VXLAN_OPT_BIT is not
\npresent, md->gbp remains 0, and vxlan_build_gbp_hdr() returns early
\nwithout modifying the VXLAN header.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
vxlan: initialize _md in vxlan_xmit_one()<\/p>\n
If a VXLAN device is configured with both VXLAN_F_COLLECT_METADATA and
\nVXLAN_F_GBP, and <\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-29121","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/29121","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=29121"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=29121"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=29121"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}