CVE-2026-98483

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().