2018-11-23 07:58:37

by Nicholas Mc Guire

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

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 <[email protected]>
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

2018-11-24 07:43:15

by Martin Blumenstingl

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

On Thu, Nov 22, 2018 at 10:41 AM Nicholas Mc Guire <[email protected]> wrote:
>
> 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 <[email protected]>
> Fixes: ed80a13bb4c4 ("mmc: meson-mx-sdio: Add a driver for the Amlogic Meson8 and Meson8b SoCs")
Acked-by: Martin Blumenstingl <[email protected]>

thank you for the patch!
I tested the non-error case on my Odroid-C1 and it still works fine.


Regards
Martin

2018-12-05 14:26:50

by Ulf Hansson

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

On Thu, 22 Nov 2018 at 10:40, Nicholas Mc Guire <[email protected]> wrote:
>
> 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 <[email protected]>
> Fixes: ed80a13bb4c4 ("mmc: meson-mx-sdio: Add a driver for the Amlogic Meson8 and Meson8b SoCs")

Applied for next, thanks!

Kind regards
Uffe

> ---
>
> 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
>