In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
nfc: llcp: reject PDUs shorter than the LLCP header<\/p>\n
Every LLCP PDU begins with a two-byte header (DSAP\/SSAP + PTYPE), but the
\nreceive path never checked that a frame is at least LLCP_HEADER_SIZE bytes
\nbefore parsing it.<\/p>\n
nfc_llcp_rx_skb() reads the header via nfc_llcp_ptype()\/nfc_llcp_dsap()\/
\nnfc_llcp_ssap(), which dereference pdu->data[0] and pdu->data[1], and a
\nCONNECT or CC PDU then computes<\/p>\n
\ttlv_array_len = skb->len – LLCP_HEADER_SIZE;<\/p>\n
as a size_t and hands it to the TLV walk. When the frame is shorter than
\nthe header the subtraction wraps to a huge value and the walk runs far
\npast the buffer, an out-of-bounds read.<\/p>\n
A nearby NFC device can reach this without authentication; LLCP link
\nactivation happens automatically after NFC-DEP.<\/p>\n
Guard the common receive choke point __nfc_llcp_recv(), shared by both the
\ntarget (nfc_llcp_data_received()) and initiator (nfc_llcp_recv()) paths, so
\na short skb is dropped before the rx_work worker parses it. Use
\npskb_may_pull() rather than a skb->len test so the two header bytes are
\nguaranteed to sit in the skb linear area even for a non-linear skb,
\nmatching how the sibling NCI and HCI receive paths validate their headers.<\/p>\n
Reproduced with a KFENCE out-of-bounds read via \/dev\/virtual_nci on
\nlinux-next.<\/p>\n
Found by 0sec automated security-research tooling (https:\/\/0sec.ai).<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
nfc: llcp: reject PDUs shorter than the LLCP header<\/p>\n
Every LLCP PDU begins with a two-byte header (DSAP\/SSAP + PTYPE), but the
\nrece<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-17302","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/17302","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=17302"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=17302"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=17302"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}