(release/25.2) xf86: prevent passing NULL pointer as strcpy destination

[metux]

Backport of #3567 (master)

Reported by gcc 16.1:
hw/xfree86/common/xf86Configure.c:463:9: warning: use of NULL where non-null
expected [CWE-476] [-Wanalyzer-null-argument]
463 | strcpy(ptr->mon_modelname, (char *) (det_mon->section.name));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
‘handle_detailed_input’: events 1-5
458 | switch (det_mon->type) {
| ^~~~~~
| |
| (1) following ‘case 252:’ branch... ─>─┐
| │
| │
|┌───────────────────────────────────────────┘
459 |│ case DS_NAME:
|│ ~~~~
|│ |
|└───>(2) ...to here
460 | ptr->mon_modelname = realloc(ptr->mon_modelname,
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| | |
| | (3) when ‘realloc’ fails
| (4) using NULL here
461 | strlen((char *) (det_mon->section.name)) +
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
462 | 1);
| ~~
463 | strcpy(ptr->mon_modelname, (char ) (det_mon->section.name));
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| |
| (5) ⚠ argument 1 (‘realloc((struct *)data.mon_modelname, strlen(&*det_mon.section.name) + 1)’) NULL where non-null expected

note: argument 1 of ‘strcpy’ must be non-null

Signed-off-by: Alan Coopersmith alan.coopersmith@oracle.com
Part-of: https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2272

[metux]

🤖 Automated review — generated by Starfleet ship Discovery on behalf of @metux. Not a human review.

Clean one-liner fix — no objections.

What it does: replaces bare realloc() with XNFrealloc() in the EDID monitor-name parsing path (handle_detailed_input, DS_NAME case). XNFrealloc is the standard X pattern for non-recoverable allocations — it aborts the server cleanly on OOM instead of returning NULL and crashing on the subsequent strcpy.

ABI impact: none. No struct layout changes, no export changes. NVIDIA blobs unaffected.

Backport candidate: yes — NULL-dereference / crash fix (CWE-476). Likely applies to release/25.1 and release/25.0 as well. Applicability per branch to be confirmed — maintainer decides.

Verdict: passes review.