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CVE-2026-80798

nfc: llcp: reject PDUs shorter than the LLCP header

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 5.10.267, 5.15.218, 6.1.185, 6.6.154, 6.12.106, and 3 more
None on Exploit-DB, Metasploit or GitHub

Summary

In the Linux kernel, the following vulnerability has been resolved: nfc: llcp: reject PDUs shorter than the LLCP header Every LLCP PDU begins with a two-byte header (DSAP/SSAP + PTYPE), but the receive path never checked that a frame is at least LLCP_HEADER_SIZE bytes before parsing it. nfc_llcp_rx_skb() reads the header via nfc_llcp_ptype()/nfc_llcp_dsap()/ nfc_llcp_ssap(), which dereference pdu->data[0] and pdu->data[1], and a CONNECT or CC PDU then computes tlv_array_len = skb->len - LLCP_HEADER_SIZE; as a size_t and hands it to the TLV walk. When the frame is shorter than the header the subtraction wraps to a huge value and the walk runs far past the buffer, an out-of-bounds read. A nearby NFC device can reach this without authentication; LLCP link activation happens automatically after NFC-DEP. Guard the common receive choke point __nfc_llcp_recv(), shared by both the target (nfc_llcp_data_received()) and initiator (nfc_llcp_recv()) paths, so a short skb is dropped before the rx_work worker parses it. Use pskb_may_pull() rather than a skb->len test so the two header bytes are guaranteed to sit in the skb linear area even for a non-linear skb, matching how the sibling NCI and HCI receive paths validate their headers. Reproduced with a KFENCE out-of-bounds read via /dev/virtual_nci on linux-next. Found by 0sec automated security-research tooling (https://0sec.ai).

Timeline

  1. CVE published
  2. Record last updated

Affected versions

  • Linux Linux

    From d646960f7986fefb460a2b062d5ccc8ccfeacc3a · fixed in e6ec76a68dce04884dfeccfe5a5f0e9f67c0ec82; From d646960f7986fefb460a2b062d5ccc8ccfeacc3a · fixed in f36cffea24bf3e2cc29a00d4b51dbcadc087d810; From d646960f7986fefb460a2b062d5ccc8ccfeacc3a · fixed in a7b9b449f5a5132221fff6adc11a9431ab8cd914; From d646960f7986fefb460a2b062d5ccc8ccfeacc3a · fixed in 3793d768b40f38bb97265dd5b9a8b8655c4e1b1d; From d646960f7986fefb460a2b062d5ccc8ccfeacc3a · fixed in eab47618e282602197db287ecbd1b09d356a2515; From d646960f7986fefb460a2b062d5ccc8ccfeacc3a · fixed in e969e98410051b1ef8cc318bfe0c7e3f24ec766d; From d646960f7986fefb460a2b062d5ccc8ccfeacc3a · fixed in ae5f20f5842f440b72d030e3a34fe182dd8eae42; From d646960f7986fefb460a2b062d5ccc8ccfeacc3a · fixed in d3d90243393c48146911c67fd3792b549d21d9e6; From d646960f7986fefb460a2b062d5ccc8ccfeacc3a · fixed in 95674f506c6376d6722a23144c9acd26609771ed

  • Linux Linux

    3.3

  • KernelLinux

    From 3.3.0 · fixed in 5.10.267; From 5.11.0 · fixed in 5.15.218; From 5.16.0 · fixed in 6.1.185; From 6.2.0 · fixed in 6.6.154; From 6.7.0 · fixed in 6.12.106; From 6.13.0 · fixed in 6.18.47; From 6.19.0 · fixed in 7.1.11; From 7.2.0 · fixed in 7.2.1

References 9

git.kernel.org