[PATCH 3.18 25/85] drm/omap: fix possible NULL ref issue in tiler_reserve_2d

[Greg Kroah-Hartman]

3.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Tomi Valkeinen <tomi.valkeinen@xxxxxx>

[ Upstream commit 6a0f0c55619f0b82a677cab72e77c3444a5eee58 ]

tiler_reserve_2d allocates memory but does not check if it got the
memory. Add the check and return ENOMEM on failure.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20180329104038.29154-2-tomi.valkeinen@xxxxxx
Reviewed-by: Emil Velikov <emil.velikov@xxxxxxxxxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Signed-off-by: Sean Paul <seanpaul@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/gpu/drm/omapdrm/omap_dmm_tiler.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/omapdrm/omap_dmm_tiler.c
+++ b/drivers/gpu/drm/omapdrm/omap_dmm_tiler.c
@@ -356,11 +356,15 @@ int tiler_unpin(struct tiler_block *bloc
 struct tiler_block *tiler_reserve_2d(enum tiler_fmt fmt, uint16_t w,
 		uint16_t h, uint16_t align)
 {
-	struct tiler_block *block = kzalloc(sizeof(*block), GFP_KERNEL);
+	struct tiler_block *block;
 	u32 min_align = 128;
 	int ret;
 	unsigned long flags;
 
+	block = kzalloc(sizeof(*block), GFP_KERNEL);
+	if (!block)
+		return ERR_PTR(-ENOMEM);
+
 	BUG_ON(!validfmt(fmt));
 
 	/* convert width/height to slots */