Bug 2536562 (CVE-2026-90223)

Summary: CVE-2026-90223 kernel: nfc: llcp: bound SNL TLV parsing to the skb and add length checks
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Near Field Communication (NFC) Logical Link Control Protocol (LLCP) in the Linux kernel. This vulnerability allows a nearby unauthenticated NFC device to trigger an out-of-bounds read during the parsing of Service Name List (SNL) Type-Length-Value (TLV) lists. This can occur due to insufficient length checks, potentially leading to information disclosure or a denial of service.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-09-17 18:24:53 UTC
In the Linux kernel, the following vulnerability has been resolved:

nfc: llcp: bound SNL TLV parsing to the skb and add length checks

nfc_llcp_recv_snl() walked the SNL TLV list using a u16 offset/length
pair derived from skb->len, without bounding reads to the actual skb
data. Three problems followed:

  - For a short frame (skb->len < LLCP_HEADER_SIZE), tlv_len underflowed.
  - The per-TLV header (type, length) was read without checking that two
    bytes remained.
  - A declared TLV length could run past the end of the buffer, and an
    SDREQ with length == 0 made "service_name_len = length - 1" underflow
    (size_t), driving an out-of-bounds read in the following strncmp() /
    nfc_llcp_sock_from_sn(). The SDRES case likewise read tlv[2]/tlv[3]
    without a length check.

A nearby NFC device can reach this without authentication; LLCP link
activation happens automatically after NFC-DEP.

Walk the TLV list by pointer, bounded by skb_tail_pointer() over the
linear skb data, and validate each TLV declared length before use. Add
explicit length checks for SDREQ (>= 1) and SDRES (exactly 2).

Found by 0sec automated security-research tooling (https://0sec.ai).