From 9c6f19421c935db05c414bdbb3645375cd600f8d Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Sat, 15 May 2021 12:53:15 +0300 Subject: [PATCH] drm: simpledrm: fix a potential NULL dereference The drm_format_info() function returns NULL if the format is unsupported, but the simplefb_get_validated_format() is expected to return error pointers. If we propagate the NULL return then it will lead to a NULL dereference in the callers. Swap the NULL and trade it in for an ERR_PTR(-EINVAL). Fixes: 11e8f5fd223b ("drm: Add simpledrm driver") Signed-off-by: Dan Carpenter Signed-off-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/YJ+aC47XX58ICXax@mwanda --- drivers/gpu/drm/tiny/simpledrm.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/tiny/simpledrm.c b/drivers/gpu/drm/tiny/simpledrm.c index f72ca3a..4f605c5 100644 --- a/drivers/gpu/drm/tiny/simpledrm.c +++ b/drivers/gpu/drm/tiny/simpledrm.c @@ -72,6 +72,7 @@ simplefb_get_validated_format(struct drm_device *dev, const char *format_name) static const struct simplefb_format formats[] = SIMPLEFB_FORMATS; const struct simplefb_format *fmt = formats; const struct simplefb_format *end = fmt + ARRAY_SIZE(formats); + const struct drm_format_info *info; if (!format_name) { drm_err(dev, "simplefb: missing framebuffer format\n"); @@ -79,8 +80,12 @@ simplefb_get_validated_format(struct drm_device *dev, const char *format_name) } while (fmt < end) { - if (!strcmp(format_name, fmt->name)) - return drm_format_info(fmt->fourcc); + if (!strcmp(format_name, fmt->name)) { + info = drm_format_info(fmt->fourcc); + if (!info) + return ERR_PTR(-EINVAL); + return info; + } ++fmt; } -- 2.7.4