* [PATCH] mmc: sdhci-msm: Fix possible NULL pointer exception
@ 2020-12-22 8:48 Md Sadre Alam
2020-12-31 6:41 ` Veerabhadrarao Badiganti
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Md Sadre Alam @ 2020-12-22 8:48 UTC (permalink / raw)
To: bjorn.andersson, adrian.hunter, ulf.hansson, linux-arm-msm,
linux-mmc, linux-kernel
Cc: mdalam, sricharan
of_device_get_match_data returns NULL when no match.
So add the NULL pointer check to avoid dereference.
Signed-off-by: Md Sadre Alam <mdalam@codeaurora.org>
---
drivers/mmc/host/sdhci-msm.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index 9c7927b..f20e424 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -2235,6 +2235,8 @@ static int sdhci_msm_probe(struct platform_device *pdev)
* the data associated with the version info.
*/
var_info = of_device_get_match_data(&pdev->dev);
+ if (!var_info)
+ goto pltfm_free;
msm_host->mci_removed = var_info->mci_removed;
msm_host->restore_dll_config = var_info->restore_dll_config;
--
2.7.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] mmc: sdhci-msm: Fix possible NULL pointer exception
2020-12-22 8:48 [PATCH] mmc: sdhci-msm: Fix possible NULL pointer exception Md Sadre Alam
@ 2020-12-31 6:41 ` Veerabhadrarao Badiganti
2021-01-05 14:39 ` Adrian Hunter
2021-01-05 19:20 ` Bjorn Andersson
2 siblings, 0 replies; 4+ messages in thread
From: Veerabhadrarao Badiganti @ 2020-12-31 6:41 UTC (permalink / raw)
To: Md Sadre Alam, bjorn.andersson, adrian.hunter, ulf.hansson,
linux-arm-msm, linux-mmc, linux-kernel
Cc: sricharan
On 12/22/2020 2:18 PM, Md Sadre Alam wrote:
> of_device_get_match_data returns NULL when no match.
> So add the NULL pointer check to avoid dereference.
>
> Signed-off-by: Md Sadre Alam <mdalam@codeaurora.org>
> ---
Reviewed-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
> drivers/mmc/host/sdhci-msm.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index 9c7927b..f20e424 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -2235,6 +2235,8 @@ static int sdhci_msm_probe(struct platform_device *pdev)
> * the data associated with the version info.
> */
> var_info = of_device_get_match_data(&pdev->dev);
> + if (!var_info)
> + goto pltfm_free;
>
> msm_host->mci_removed = var_info->mci_removed;
> msm_host->restore_dll_config = var_info->restore_dll_config;
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] mmc: sdhci-msm: Fix possible NULL pointer exception
2020-12-22 8:48 [PATCH] mmc: sdhci-msm: Fix possible NULL pointer exception Md Sadre Alam
2020-12-31 6:41 ` Veerabhadrarao Badiganti
@ 2021-01-05 14:39 ` Adrian Hunter
2021-01-05 19:20 ` Bjorn Andersson
2 siblings, 0 replies; 4+ messages in thread
From: Adrian Hunter @ 2021-01-05 14:39 UTC (permalink / raw)
To: Md Sadre Alam, bjorn.andersson, ulf.hansson, linux-arm-msm,
linux-mmc, linux-kernel
Cc: sricharan
On 22/12/20 10:48 am, Md Sadre Alam wrote:
> of_device_get_match_data returns NULL when no match.
> So add the NULL pointer check to avoid dereference.
>
> Signed-off-by: Md Sadre Alam <mdalam@codeaurora.org>
> ---
> drivers/mmc/host/sdhci-msm.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index 9c7927b..f20e424 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -2235,6 +2235,8 @@ static int sdhci_msm_probe(struct platform_device *pdev)
> * the data associated with the version info.
> */
> var_info = of_device_get_match_data(&pdev->dev);
> + if (!var_info)
Shouldn't you set ret to -ENODEV here?
> + goto pltfm_free;
>
> msm_host->mci_removed = var_info->mci_removed;
> msm_host->restore_dll_config = var_info->restore_dll_config;
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] mmc: sdhci-msm: Fix possible NULL pointer exception
2020-12-22 8:48 [PATCH] mmc: sdhci-msm: Fix possible NULL pointer exception Md Sadre Alam
2020-12-31 6:41 ` Veerabhadrarao Badiganti
2021-01-05 14:39 ` Adrian Hunter
@ 2021-01-05 19:20 ` Bjorn Andersson
2 siblings, 0 replies; 4+ messages in thread
From: Bjorn Andersson @ 2021-01-05 19:20 UTC (permalink / raw)
To: Md Sadre Alam
Cc: adrian.hunter, ulf.hansson, linux-arm-msm, linux-mmc,
linux-kernel, sricharan
On Tue 22 Dec 02:48 CST 2020, Md Sadre Alam wrote:
> of_device_get_match_data returns NULL when no match.
> So add the NULL pointer check to avoid dereference.
>
> Signed-off-by: Md Sadre Alam <mdalam@codeaurora.org>
> ---
> drivers/mmc/host/sdhci-msm.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index 9c7927b..f20e424 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -2235,6 +2235,8 @@ static int sdhci_msm_probe(struct platform_device *pdev)
> * the data associated with the version info.
> */
> var_info = of_device_get_match_data(&pdev->dev);
> + if (!var_info)
To get this you (the SDHCI driver developer) needs to add an entry in
sdhci_msm_dt_match[] without a .data specified.
> + goto pltfm_free;
And this will cause sdhci_msm_probe() to return 0, giving no hint to
said developer that they screwed up. Given that this can only be caused
by a developer working on this driver you should provide feedback
suitable for such developer, e.g. by:
if (WARN_ON(!var_info))
return -EINVAL;
But given that this is only for the developer himself, I don't see that
this adds any value over just reading the callstack you get from the
panic when the next line dereferences var_info (NULL).
Regards,
Bjorn
>
> msm_host->mci_removed = var_info->mci_removed;
> msm_host->restore_dll_config = var_info->restore_dll_config;
> --
> 2.7.4
>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-01-05 19:21 UTC | newest]
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2020-12-22 8:48 [PATCH] mmc: sdhci-msm: Fix possible NULL pointer exception Md Sadre Alam
2020-12-31 6:41 ` Veerabhadrarao Badiganti
2021-01-05 14:39 ` Adrian Hunter
2021-01-05 19:20 ` Bjorn Andersson
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