CVEvulnerability
CVE-2026-98483
- Status
- Received
- Published
- 2026-10-18
- Last modified
- 2026-10-19
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
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().
References
- https://git.kernel.org/stable/c/19bcfc2a56d0b82919079b5424c5a9a0ac897dcf git.kernel.org
- https://git.kernel.org/stable/c/25bfa673adc70189c0bc872940421ae59f789cf6 git.kernel.org
- https://git.kernel.org/stable/c/2b31d0cc95856c856ada91f943fb14dfdf29a923 git.kernel.org
- https://git.kernel.org/stable/c/841af260ff477f6191872bc3b2e15488615c1827 git.kernel.org
- https://git.kernel.org/stable/c/9ede11e12f965ace97c4e0f606667f24fb41e7e1 git.kernel.org
- https://git.kernel.org/stable/c/c40f61a6a413f3eaf028e5fe367fd9749e503ab0 git.kernel.org
- https://git.kernel.org/stable/c/d8c929e9afdbc33b1876ecb97a517e850449b5bd git.kernel.org
- https://git.kernel.org/stable/c/dcab71a7011918f6fdba7adcec02d217dcb84b8d git.kernel.org