CVE-2026-90226
nfc: llcp: avoid userspace overflow on invalid optlen
Description
In the Linux kernel, the following vulnerability has been resolved: nfc: llcp: avoid userspace overflow on invalid optlen nfc_llcp_getsockopt() casts optval to (u32 __user *) for put_user(), so the kernel always stores 4 bytes regardless of the caller-supplied optlen. The existing min_t(u32, len, sizeof(u32)) only clamps the length reported back to userspace; it does not constrain the store. A call with optlen < 4 therefore writes past the user buffer, violating the getsockopt(2) contract for all five supported optnames. Reject any call with optlen < sizeof(u32) up front. 'len' is int, so a plain size comparison would promote a negative optlen to size_t and slip past the check; an explicit 'len < 0' test is added first to catch negative values before the size compare.
INFO
Published Date :
Sept. 17, 2026, 5:17 p.m.
Last Modified :
Sept. 17, 2026, 5:17 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Validate optlen is not less than 4 bytes.
- Check for negative optlen values.
- Apply the patch to the Linux kernel.
References to Advisories, Solutions, and Tools
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information, practical solutions, and valuable tools related to
CVE-2026-90226.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-90226 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-90226
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-90226 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-90226 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 17, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: nfc: llcp: avoid userspace overflow on invalid optlen nfc_llcp_getsockopt() casts optval to (u32 __user *) for put_user(), so the kernel always stores 4 bytes regardless of the caller-supplied optlen. The existing min_t(u32, len, sizeof(u32)) only clamps the length reported back to userspace; it does not constrain the store. A call with optlen < 4 therefore writes past the user buffer, violating the getsockopt(2) contract for all five supported optnames. Reject any call with optlen < sizeof(u32) up front. 'len' is int, so a plain size comparison would promote a negative optlen to size_t and slip past the check; an explicit 'len < 0' test is added first to catch negative values before the size compare. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/90xxx/CVE-2026-90226.json">CVE-2026-90226</a> Added Reference https://git.kernel.org/stable/c/35573c6cb081af2f4a7caeea291302aca5484526 Added Reference https://git.kernel.org/stable/c/42859562b7cc4313a84a584f338118edb7087066 Added Reference https://git.kernel.org/stable/c/598dcd53c52f8eeb9dd5382198c03960d5d40fcd Added Reference https://git.kernel.org/stable/c/7e40f2f5e7bc06c3ddef781180ce4f7994176547 Added Reference https://git.kernel.org/stable/c/8bf228fa02b1ed8ce622fb81fa8edc42be9aeb67 Added Reference https://git.kernel.org/stable/c/99985bfa8336fadcc69190ba2dcbd5386af3d661 Added Reference https://git.kernel.org/stable/c/b4c5abaea06292e1dddb70eac1b51589b32c77a3 Added Reference https://git.kernel.org/stable/c/bd6f1277b62bc1df348ca21739df2bc546fcd493