CVE-2026-98483: nfc: fix use-after-free in nfc_get_local_general_bytes

Severity: unknown
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-18 · updated 2026-10-19

Description

In the Linux kernel, the following vulnerability has been resolved: nfc: fix use-after-free in nfc_get_local_general_bytes Commit 6709d4b7bc2e ("net: nfc: Fix use-after-free caused by nfc_llcp_find_local") attempted to fix a use-after-free (UAF) issue by invoking nfc_llcp_local_put(local) after accessing local->gb. However, if the reference count drops to zero, local is freed immediately, leading to a use-after-free when callers access the returned pointer. Alternative approaches using dynamic allocation (e.g. kmemdup) introduced memory leaks because callers consistently treat the returned pointer as borrowed memory. Fix this properly by refactoring nfc_llcp_general_bytes() and nfc_get_local_general_bytes() to accept a caller-provided output buffer (out_gb) and its maximum length (gb_max_len). The general bytes are safely copied into out_gb before calling nfc_llcp_local_put(local), ensuring safe lifetime management without ownership transfer complications. Update all callers across drivers (microread, pn533, pn544, st21nfca, digital_dep, and nci) to provide their own destination buffers and pass them to nfc_get_local_general_bytes().

Affected products

Linux kernel: from 5.10.188 before 5.10.271; from 5.15.121 before 5.15.222; from 6.1.39 before 6.1.189; from 5.4.251 before 5.5; from 6.3.13 before 6.4; from 6.4.4 before 6.5 — fixed in 5.10.271, 5.15.222, 5.5, 6.1.189, 6.4, 6.5

How to fix

Upgrade to a fixed version: Linux kernel 5.10.271, 5.15.222, 5.5, 6.1.189. Check the vendor advisory for mitigations.

References

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