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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, Arnaud Pouliquen <arnaud.pouliquen@st.com>,
        Suman Anna <s-anna@ti.com>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.19 136/220] remoteproc: Check for NULL firmwares in sysfs interface
Date:   Fri, 22 Nov 2019 11:28:21 +0100
Message-Id: <20191122100922.594417540@linuxfoundation.org>
In-Reply-To: <20191122100912.732983531@linuxfoundation.org>
References: <20191122100912.732983531@linuxfoundation.org>
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From: Suman Anna <s-anna@ti.com>

[ Upstream commit faeadbb64094757150a8c2a3175ca418dbdd472c ]

The remoteproc framework provides a sysfs file 'firmware'
for modifying the firmware image name from userspace. Add
an additional check to ensure NULL firmwares are errored
out right away, rather than getting a delayed error while
requesting a firmware during the start of a remoteproc
later on.

Tested-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/remoteproc/remoteproc_sysfs.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c
index 47be411400e56..3a4c3d7cafca3 100644
--- a/drivers/remoteproc/remoteproc_sysfs.c
+++ b/drivers/remoteproc/remoteproc_sysfs.c
@@ -48,6 +48,11 @@ static ssize_t firmware_store(struct device *dev,
 	}
 
 	len = strcspn(buf, "\n");
+	if (!len) {
+		dev_err(dev, "can't provide a NULL firmware\n");
+		err = -EINVAL;
+		goto out;
+	}
 
 	p = kstrndup(buf, len, GFP_KERNEL);
 	if (!p) {
-- 
2.20.1