Bug 2554891 (CVE-2026-98483) - CVE-2026-98483 kernel: nfc: fix use-after-free in nfc_get_local_general_bytes
Summary: CVE-2026-98483 kernel: nfc: fix use-after-free in nfc_get_local_general_bytes
Keywords:
Status: NEW
Alias: CVE-2026-98483
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-10-18 15:25 UTC by OSIDB Bzimport
Modified: 2026-10-20 11:13 UTC (History)
17 users (show)

Fixed In Version:
Clone Of:
Environment:
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Description OSIDB Bzimport 2026-10-18 15:25:55 UTC
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().


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