media: venus: venc: Fix potential null pointer dereference on pointer fmt

stable inclusion
from stable-5.10.65
commit eda4ccca906fa2b007d7e4a4f97fb53977633d3f
bugzilla: 182361 https://gitee.com/openeuler/kernel/issues/I4EH3U

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=eda4ccca906fa2b007d7e4a4f97fb53977633d3f

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

[ Upstream commit 09ea9719 ]

Currently the call to find_format can potentially return a NULL to
fmt and the nullpointer is later dereferenced on the assignment of
pixmp->num_planes = fmt->num_planes.  Fix this by adding a NULL pointer
check and returning NULL for the failure case.

Addresses-Coverity: ("Dereference null return")

Fixes: aaaa93ed ("[media] media: venus: venc: add video encoder files")
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NStanimir Varbanov <stanimir.varbanov@linaro.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/media/platform/qcom/venus/venc.c

@@ -183,6 +183,8 @@ venc_try_fmt_common(struct venus_inst *inst, struct v4l2_format *f)
 		else
 			return NULL;
 		fmt = find_format(inst, pixmp->pixelformat, f->type);
+		if (!fmt)
+			return NULL;
 	}
 
 	pixmp->width = clamp(pixmp->width, frame_width_min(inst),