[PATCH] mmc: meson-mx-sdio: check devm_kasprintf for failure

From: Nicholas Mc Guire <hofrat@osadl.org>
To: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Carlo Caione <carlo@caione.org>,
	Kevin Hilman <khilman@baylibre.com>,
	linux-mmc@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org,
	Nicholas Mc Guire <hofrat@osadl.org>
Subject: [PATCH] mmc: meson-mx-sdio: check devm_kasprintf for failure
Date: Thu, 22 Nov 2018 10:35:19 +0100	[thread overview]
Message-ID: <1542879319-2196-1-git-send-email-hofrat@osadl.org> (raw)

devm_kasprintf() may return NULL on failure of internal allocation thus
the assignments to  init.name  are not safe if not checked. On error
meson_mx_mmc_register_clks() returns negative values so -ENOMEM in the
(unlikely) failure case of devm_kasprintf() should be fine here.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Fixes: ed80a13bb4c4 ("mmc: meson-mx-sdio: Add a driver for the Amlogic Meson8 and Meson8b SoCs")
---

Problem located with an experimental coccinelle script

Patch was compile tested with: multi_v7_defconfig (implies ARCH_MESON=y &
MMC_MESON_MX_SDIO=y)

Patch is against 4.20-rc3 (localversion-next is next-20181122)

 drivers/mmc/host/meson-mx-sdio.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/mmc/host/meson-mx-sdio.c b/drivers/mmc/host/meson-mx-sdio.c
index abe253c..ec980bd 100644
--- a/drivers/mmc/host/meson-mx-sdio.c
+++ b/drivers/mmc/host/meson-mx-sdio.c
@@ -596,6 +596,9 @@ static int meson_mx_mmc_register_clks(struct meson_mx_mmc_host *host)
 	init.name = devm_kasprintf(host->controller_dev, GFP_KERNEL,
 				   "%s#fixed_factor",
 				   dev_name(host->controller_dev));
+	if (!init.name)
+		return -ENOMEM;
+
 	init.ops = &clk_fixed_factor_ops;
 	init.flags = 0;
 	init.parent_names = &clk_fixed_factor_parent;
@@ -612,6 +615,9 @@ static int meson_mx_mmc_register_clks(struct meson_mx_mmc_host *host)
 	clk_div_parent = __clk_get_name(host->fixed_factor_clk);
 	init.name = devm_kasprintf(host->controller_dev, GFP_KERNEL,
 				   "%s#div", dev_name(host->controller_dev));
+	if (!init.name)
+		return -ENOMEM;
+
 	init.ops = &clk_divider_ops;
 	init.flags = CLK_SET_RATE_PARENT;
 	init.parent_names = &clk_div_parent;
-- 
2.1.4

