Re: [PATCH] drivers: thermal: qcom: tsens: Fix memory leak from qfprom read

[Amit Kucheria]

On Fri, Aug 23, 2019 at 3:08 PM Srinivas Kandagatla
<srinivas.kandagatla@xxxxxxxxxx> wrote:
>
> memory returned as part of nvmem_read via qfprom_read should be
> freed by the consumer once done.
> Existing code is not doing it so fix it.
>
> Below memory leak detected by kmemleak
>    [<ffffff80088b7658>] kmemleak_alloc+0x50/0x84
>     [<ffffff80081df120>] __kmalloc+0xe8/0x168
>     [<ffffff80086db350>] nvmem_cell_read+0x30/0x80
>     [<ffffff8008632790>] qfprom_read+0x4c/0x7c
>     [<ffffff80086335a4>] calibrate_v1+0x34/0x204
>     [<ffffff8008632518>] tsens_probe+0x164/0x258
>     [<ffffff80084e0a1c>] platform_drv_probe+0x80/0xa0
>     [<ffffff80084de4f4>] really_probe+0x208/0x248
>     [<ffffff80084de2c4>] driver_probe_device+0x98/0xc0
>     [<ffffff80084dec54>] __device_attach_driver+0x9c/0xac
>     [<ffffff80084dca74>] bus_for_each_drv+0x60/0x8c
>     [<ffffff80084de634>] __device_attach+0x8c/0x100
>     [<ffffff80084de6c8>] device_initial_probe+0x20/0x28
>     [<ffffff80084dcbb8>] bus_probe_device+0x34/0x7c
>     [<ffffff80084deb08>] deferred_probe_work_func+0x6c/0x98
>     [<ffffff80080c3da8>] process_one_work+0x160/0x2f8
>
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>

Acked-by: Amit Kucheria <amit.kucheria@xxxxxxxxxx>

> ---
>  drivers/thermal/qcom/tsens-8960.c |  2 ++
>  drivers/thermal/qcom/tsens-v0_1.c | 12 ++++++++++--
>  drivers/thermal/qcom/tsens-v1.c   |  1 +
>  drivers/thermal/qcom/tsens.h      |  1 +
>  4 files changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/thermal/qcom/tsens-8960.c b/drivers/thermal/qcom/tsens-8960.c
> index 8d9b721dadb6..e46a4e3f25c4 100644
> --- a/drivers/thermal/qcom/tsens-8960.c
> +++ b/drivers/thermal/qcom/tsens-8960.c
> @@ -229,6 +229,8 @@ static int calibrate_8960(struct tsens_priv *priv)
>         for (i = 0; i < num_read; i++, s++)
>                 s->offset = data[i];
>
> +       kfree(data);
> +
>         return 0;
>  }
>
> diff --git a/drivers/thermal/qcom/tsens-v0_1.c b/drivers/thermal/qcom/tsens-v0_1.c
> index 6f26fadf4c27..055647bcee67 100644
> --- a/drivers/thermal/qcom/tsens-v0_1.c
> +++ b/drivers/thermal/qcom/tsens-v0_1.c
> @@ -145,8 +145,10 @@ static int calibrate_8916(struct tsens_priv *priv)
>                 return PTR_ERR(qfprom_cdata);
>
>         qfprom_csel = (u32 *)qfprom_read(priv->dev, "calib_sel");
> -       if (IS_ERR(qfprom_csel))
> +       if (IS_ERR(qfprom_csel)) {
> +               kfree(qfprom_cdata);
>                 return PTR_ERR(qfprom_csel);
> +       }
>
>         mode = (qfprom_csel[0] & MSM8916_CAL_SEL_MASK) >> MSM8916_CAL_SEL_SHIFT;
>         dev_dbg(priv->dev, "calibration mode is %d\n", mode);
> @@ -181,6 +183,8 @@ static int calibrate_8916(struct tsens_priv *priv)
>         }
>
>         compute_intercept_slope(priv, p1, p2, mode);
> +       kfree(qfprom_cdata);
> +       kfree(qfprom_csel);
>
>         return 0;
>  }
> @@ -198,8 +202,10 @@ static int calibrate_8974(struct tsens_priv *priv)
>                 return PTR_ERR(calib);
>
>         bkp = (u32 *)qfprom_read(priv->dev, "calib_backup");
> -       if (IS_ERR(bkp))
> +       if (IS_ERR(bkp)) {
> +               kfree(calib);
>                 return PTR_ERR(bkp);
> +       }
>
>         calib_redun_sel =  bkp[1] & BKP_REDUN_SEL;
>         calib_redun_sel >>= BKP_REDUN_SHIFT;
> @@ -313,6 +319,8 @@ static int calibrate_8974(struct tsens_priv *priv)
>         }
>
>         compute_intercept_slope(priv, p1, p2, mode);
> +       kfree(calib);
> +       kfree(bkp);
>
>         return 0;
>  }
> diff --git a/drivers/thermal/qcom/tsens-v1.c b/drivers/thermal/qcom/tsens-v1.c
> index 10b595d4f619..870f502f2cb6 100644
> --- a/drivers/thermal/qcom/tsens-v1.c
> +++ b/drivers/thermal/qcom/tsens-v1.c
> @@ -138,6 +138,7 @@ static int calibrate_v1(struct tsens_priv *priv)
>         }
>
>         compute_intercept_slope(priv, p1, p2, mode);
> +       kfree(qfprom_cdata);
>
>         return 0;
>  }
> diff --git a/drivers/thermal/qcom/tsens.h b/drivers/thermal/qcom/tsens.h
> index 2fd94997245b..b89083b61c38 100644
> --- a/drivers/thermal/qcom/tsens.h
> +++ b/drivers/thermal/qcom/tsens.h
> @@ -17,6 +17,7 @@
>
>  #include <linux/thermal.h>
>  #include <linux/regmap.h>
> +#include <linux/slab.h>
>
>  struct tsens_priv;
>
> --
> 2.21.0
>