From 6080a89357cc46f3450839a84af75c3d18f57772 Mon Sep 17 00:00:00 2001 From: Tomi Valkeinen Date: Thu, 15 Jan 2015 13:47:19 +0200 Subject: [PATCH] fbdev: fix cea_modes array size CEA defines 64 modes, indexed from 1 to 64. modedb has cea_modes arrays, which contains 64 entries. However, the code uses the CEA indices directly, i.e. the first mode is at cea_modes[1]. This means the array is one too short. This does not cause references to uninitialized memory as the code in fbmon only allows indexes up to 63, and the cea_modes does not contain an entry for the mode 64 so it could not be used in any case. However, the code contains a check 'if (idx > ARRAY_SIZE(cea_modes)', and while that check is a no-op as at that point idx cannot be >= 63, it upsets static checkers. Fix this by increasing the cea_array size to be 65, and change the code to allow mode 64. Signed-off-by: Tomi Valkeinen Reported-by: Dan Carpenter --- drivers/video/fbdev/core/fbmon.c | 4 ++-- drivers/video/fbdev/core/modedb.c | 2 +- include/linux/fb.h | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/video/fbdev/core/fbmon.c b/drivers/video/fbdev/core/fbmon.c index d787533d9c8b..47c3191ec313 100644 --- a/drivers/video/fbdev/core/fbmon.c +++ b/drivers/video/fbdev/core/fbmon.c @@ -1072,9 +1072,9 @@ void fb_edid_add_monspecs(unsigned char *edid, struct fb_monspecs *specs) for (i = specs->modedb_len + num; i < specs->modedb_len + num + svd_n; i++) { int idx = svd[i - specs->modedb_len - num]; - if (!idx || idx > 63) { + if (!idx || idx >= ARRAY_SIZE(cea_modes)) { pr_warning("Reserved SVD code %d\n", idx); - } else if (idx > ARRAY_SIZE(cea_modes) || !cea_modes[idx].xres) { + } else if (!cea_modes[idx].xres) { pr_warning("Unimplemented SVD code %d\n", idx); } else { memcpy(&m[i], cea_modes + idx, sizeof(m[i])); diff --git a/drivers/video/fbdev/core/modedb.c b/drivers/video/fbdev/core/modedb.c index 7d07cf824b64..2510fa728d77 100644 --- a/drivers/video/fbdev/core/modedb.c +++ b/drivers/video/fbdev/core/modedb.c @@ -289,7 +289,7 @@ static const struct fb_videomode modedb[] = { }; #ifdef CONFIG_FB_MODE_HELPERS -const struct fb_videomode cea_modes[64] = { +const struct fb_videomode cea_modes[65] = { /* #1: 640x480p@59.94/60Hz */ [1] = { NULL, 60, 640, 480, 39722, 48, 16, 33, 10, 96, 2, 0, diff --git a/include/linux/fb.h b/include/linux/fb.h index 043f3283b71c..bc9afa74ee11 100644 --- a/include/linux/fb.h +++ b/include/linux/fb.h @@ -788,7 +788,7 @@ struct dmt_videomode { extern const char *fb_mode_option; extern const struct fb_videomode vesa_modes[]; -extern const struct fb_videomode cea_modes[64]; +extern const struct fb_videomode cea_modes[65]; extern const struct dmt_videomode dmt_modes[]; struct fb_modelist { -- 2.39.5