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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Colin Ian King <colin.king@canonical.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.7 155/393] staging: most: avoid null pointer dereference when iface is null
Date:   Mon, 17 Aug 2020 17:13:25 +0200
Message-Id: <20200817143827.135155225@linuxfoundation.org>
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From: Colin Ian King <colin.king@canonical.com>

[ Upstream commit e4463e49e29f43eecec86e2e2b2e2ab4feb7d867 ]

In the case where the pointer iface is null then the reporting of this
error will dereference iface when printing an error message causing which
is not ideal.  Since the majority of callers to most_register_interface
report an error when -EINVAL is returned a simple fix is to just remove
the error message, I doubt it will be missed.

Addresses-Coverity: ("Dereference after null check")
Fixes: 57562a72414c ("Staging: most: add MOST driver's core module")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20200624163957.11676-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/most/core.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/most/core.c b/drivers/most/core.c
index f781c46cd4af9..353ab277cbc6b 100644
--- a/drivers/most/core.c
+++ b/drivers/most/core.c
@@ -1283,10 +1283,8 @@ int most_register_interface(struct most_interface *iface)
 	struct most_channel *c;
 
 	if (!iface || !iface->enqueue || !iface->configure ||
-	    !iface->poison_channel || (iface->num_channels > MAX_CHANNELS)) {
-		dev_err(iface->dev, "Bad interface or channel overflow\n");
+	    !iface->poison_channel || (iface->num_channels > MAX_CHANNELS))
 		return -EINVAL;
-	}
 
 	id = ida_simple_get(&mdev_id, 0, 0, GFP_KERNEL);
 	if (id < 0) {
-- 
2.25.1