From: Sebastian Reichel <sre@kernel.org>
To: Yizhuo <yzhai003@ucr.edu>
Cc: csong@cs.ucr.edu, zhiyunq@cs.ucr.edu, linux-pm@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] power: supply: max17042_battery: fix the potential uninitialized use in max17042_write_verify_reg()
Date: Mon, 14 Oct 2019 05:31:08 +0200 [thread overview]
Message-ID: <20191014033108.jgb2c7yy3y46l6tp@earth.universe> (raw)
In-Reply-To: <20191002154406.8875-1-yzhai003@ucr.edu>
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Hi,
On Wed, Oct 02, 2019 at 08:44:06AM -0700, Yizhuo wrote:
> In function max17042_write_verify_reg(), variable "read_value"
> could be uninitialized if regmap_read() fails. However,
> "read_value" is used to decide the control flow later in the if
> statement, which is potentially unsafe.
>
> Signed-off-by: Yizhuo <yzhai003@ucr.edu>
> ---
Instead of directly failing, integrate this into
the retry loop. Also the Signed-off-by and patch
author name looks incomplete.
Thanks,
-- Sebastian
> drivers/power/supply/max17042_battery.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/power/supply/max17042_battery.c b/drivers/power/supply/max17042_battery.c
> index 0dfad2cf13fe..e6a2dacaa730 100644
> --- a/drivers/power/supply/max17042_battery.c
> +++ b/drivers/power/supply/max17042_battery.c
> @@ -486,12 +486,15 @@ static void max17042_external_power_changed(struct power_supply *psy)
> static int max17042_write_verify_reg(struct regmap *map, u8 reg, u32 value)
> {
> int retries = 8;
> - int ret;
> + int ret, err;
> u32 read_value;
>
> do {
> ret = regmap_write(map, reg, value);
> - regmap_read(map, reg, &read_value);
> + err = regmap_read(map, reg, &read_value);
> + if (err)
> + return err;
> +
> if (read_value != value) {
> ret = -EIO;
> retries--;
> --
> 2.17.1
>
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prev parent reply other threads:[~2019-10-14 3:31 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-02 15:44 [PATCH] power: supply: max17042_battery: fix the potential uninitialized use in max17042_write_verify_reg() Yizhuo
2019-10-14 3:31 ` Sebastian Reichel [this message]
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