In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
ipv6: sr: enforce exact attribute length for SEG6_ATTR_DST<\/p>\n
In seg6_genl_policy, SEG6_ATTR_DST is defined with .type = NLA_BINARY and
\n.len = sizeof(struct in6_addr). For NLA_BINARY, .len only enforces the
\nmaximum payload length and permits shorter payloads (e.g., 0 bytes).
\nWhen seg6_genl_set_tunsrc() copies sizeof(struct in6_addr) bytes via
\nkmemdup(val, sizeof(*val), GFP_KERNEL), a short SEG6_ATTR_DST attribute
\ntriggers a 16-byte out-of-bounds read past skb->tail into uninitialized
\nskb->head memory, which is stored in sdata->tun_src and leaked back to
\nuserspace via SEG6_CMD_GET_TUNSRC.<\/p>\n
Switch SEG6_ATTR_DST in seg6_genl_policy to
\nNLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)) so that generic netlink
\nvalidation rejects any attribute whose length is not exactly
\nsizeof(struct in6_addr) with -ERANGE.<\/p>\n
Tested in QEMU against Linux 7.3.0-rc3 by sending a SEG6_CMD_SET_TUNSRC
\nGeneric Netlink message with a 0-byte SEG6_ATTR_DST attribute followed
\nby SEG6_CMD_GET_TUNSRC. On the unfixed kernel, SEG6_CMD_SET_TUNSRC
\nsucceeds (err = 0) and SEG6_CMD_GET_TUNSRC leaks 16 bytes of
\nuninitialized kernel heap memory (tun_src =
\n836a61ecc4d25a1042a8d60411cfb378); with this patch applied,
\nSEG6_CMD_SET_TUNSRC is rejected by netlink policy validation with
\n-ERANGE (-34) and tun_src remains zeroed.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
ipv6: sr: enforce exact attribute length for SEG6_ATTR_DST<\/p>\n
In seg6_genl_policy, SEG6_ATTR_DST is defined with .type = NLA_BINARY a<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-41003","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/41003","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=41003"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=41003"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=41003"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}