ALSA: hda/ca0132 - fix possible NULL pointer use

[ Upstream commit 46a049dae771b95e77ac6c823330f4a60f600236 ]

gcc-7 caught what it considers a NULL pointer dereference:

sound/pci/hda/patch_ca0132.c: In function 'dspio_scp.constprop':
sound/pci/hda/patch_ca0132.c:1487:4: error: argument 1 null where non-null expected [-Werror=nonnull]

This is plausible from looking at the function, as we compare 'reply'
to NULL earlier in it. I have not tried to analyze if there are constraints
that make it impossible to hit the bug, but adding another NULL check in
the end kills the warning and makes the function more robust.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>

diff --git a/sound/pci/hda/patch_ca0132.c b/sound/pci/hda/patch_ca0132.c
index 0374bd5b61c82e42064d5020dc0879bb8588fda5..1fb9512253189423371291525201e34d332adb94 100644 (file)
--- a/sound/pci/hda/patch_ca0132.c
+++ b/sound/pci/hda/patch_ca0132.c
@@ -1452,6 +1452,9 @@ static int dspio_scp(struct hda_codec *codec,
                } else if (ret_size != reply_data_size) {
                        codec_dbg(codec, "RetLen and HdrLen .NE.\n");
                        return -EINVAL;
+               } else if (!reply) {
+                       codec_dbg(codec, "NULL reply\n");
+                       return -EINVAL;
                } else {
                        *reply_len = ret_size*sizeof(unsigned int);
                        memcpy(reply, scp_reply.data, *reply_len);