git: 848a8bf3f40d - main - fb: Check for errors from copyin()

[Mark Johnston]

The branch main has been updated by markj:

URL: 
https://cgit.FreeBSD.org/src/commit/?id=848a8bf3f40d91bda0ae3ab67f22ed693f25f9c4

commit 848a8bf3f40d91bda0ae3ab67f22ed693f25f9c4
Author:     Mark Johnston <ma...@freebsd.org>
AuthorDate: 2024-01-12 15:09:22 +0000
Commit:     Mark Johnston <ma...@freebsd.org>
CommitDate: 2024-01-12 20:56:00 +0000

    fb: Check for errors from copyin()
    
    When compiling with gcc, a function annotated with __result_use_check
    cannot have its return value ignored with a void cast.  So, try to
    handle it.
    
    MFC after:      1 week
---
 sys/dev/fb/vesa.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/sys/dev/fb/vesa.c b/sys/dev/fb/vesa.c
index e1cca3a70725..dcd3d34076bf 100644
--- a/sys/dev/fb/vesa.c
+++ b/sys/dev/fb/vesa.c
@@ -1732,11 +1732,15 @@ set_palette(video_adapter_t *adp, int base, int count,
        r = malloc(count * 3, M_DEVBUF, M_WAITOK | M_ZERO);
        g = r + count;
        b = g + count;
-       (void)copyin(red, r, count);
-       (void)copyin(green, g, count);
-       (void)copyin(blue, b, count);
+       if (copyin(red, r, count) != 0 ||
+           copyin(green, g, count) != 0 ||
+           copyin(blue, b, count) != 0) {
+               error = 1;
+               goto out;
+       }
 
        error = vesa_bios_load_palette2(base, count, r, g, b, bits);
+out:
        free(r, M_DEVBUF);
 
        return (error);