* [PATCH] mmc: host: fix a possible null pointer access.
@ 2019-12-17 3:17 Pan Zhang
2019-12-18 11:52 ` Ulf Hansson
0 siblings, 1 reply; 4+ messages in thread
From: Pan Zhang @ 2019-12-17 3:17 UTC (permalink / raw)
To: zhangpan26, hushiyuan, jh80.chung, ulf.hansson, p.zabel
Cc: linux-mmc, linux-kernel
3419 if (host->slot &&
3420 (mmc_can_gpio_cd(host->slot->mmc) ||
3421 !mmc_card_is_removable(host->slot->mmc))) {
3422 ret = clk_prepare_enable(host->biu_clk);
3423 if (ret)
3424 return ret;
3425 }
We previously assumed 'host->slot' could be null (see line 3419).
The following situation is similar, so add a judgement.
Signed-off-by: Pan Zhang <zhangpan26@huawei.com>
---
drivers/mmc/host/dw_mmc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index fc9d4d0..8e27c52 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -3454,7 +3454,7 @@ int dw_mci_runtime_resume(struct device *dev)
mci_writel(host, CTRL, SDMMC_CTRL_INT_ENABLE);
- if (host->slot->mmc->pm_flags & MMC_PM_KEEP_POWER)
+ if (host->slot && (host->slot->mmc->pm_flags & MMC_PM_KEEP_POWER))
dw_mci_set_ios(host->slot->mmc, &host->slot->mmc->ios);
/* Force setup bus to guarantee available clock output */
--
2.7.4
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] mmc: host: fix a possible null pointer access.
2019-12-17 3:17 [PATCH] mmc: host: fix a possible null pointer access Pan Zhang
@ 2019-12-18 11:52 ` Ulf Hansson
2019-12-19 6:28 ` Pan Zhang
0 siblings, 1 reply; 4+ messages in thread
From: Ulf Hansson @ 2019-12-18 11:52 UTC (permalink / raw)
To: Pan Zhang
Cc: hushiyuan, Jaehoon Chung, Philipp Zabel, linux-mmc,
Linux Kernel Mailing List
On Tue, 17 Dec 2019 at 04:18, Pan Zhang <zhangpan26@huawei.com> wrote:
>
> 3419 if (host->slot &&
> 3420 (mmc_can_gpio_cd(host->slot->mmc) ||
> 3421 !mmc_card_is_removable(host->slot->mmc))) {
> 3422 ret = clk_prepare_enable(host->biu_clk);
> 3423 if (ret)
> 3424 return ret;
> 3425 }
>
> We previously assumed 'host->slot' could be null (see line 3419).
>
> The following situation is similar, so add a judgement.
>
> Signed-off-by: Pan Zhang <zhangpan26@huawei.com>
> ---
> drivers/mmc/host/dw_mmc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index fc9d4d0..8e27c52 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -3454,7 +3454,7 @@ int dw_mci_runtime_resume(struct device *dev)
> mci_writel(host, CTRL, SDMMC_CTRL_INT_ENABLE);
>
>
> - if (host->slot->mmc->pm_flags & MMC_PM_KEEP_POWER)
> + if (host->slot && (host->slot->mmc->pm_flags & MMC_PM_KEEP_POWER))
> dw_mci_set_ios(host->slot->mmc, &host->slot->mmc->ios);
This shouldn't be a problem as the ->runtime_resume() callback can't
be invoked, unless there is a slot.
>
> /* Force setup bus to guarantee available clock output */
> --
> 2.7.4
>
Kind regards
Uffe
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: Re: [PATCH] mmc: host: fix a possible null pointer access.
2019-12-18 11:52 ` Ulf Hansson
@ 2019-12-19 6:28 ` Pan Zhang
2019-12-19 7:07 ` Ulf Hansson
0 siblings, 1 reply; 4+ messages in thread
From: Pan Zhang @ 2019-12-19 6:28 UTC (permalink / raw)
To: ulf.hansson, p.zabel, jh80.chung, zhangpan26, hushiyuan
Cc: linux-mmc, linux-kernel
On Wed, 18 Dec 2019 at 7:52 p.m., Ulf Hansson <ulf.hansson@linaro.org> wrote:
>>
>> 3419 if (host->slot &&
>> 3420 (mmc_can_gpio_cd(host->slot->mmc) ||
>> 3421 !mmc_card_is_removable(host->slot->mmc))) {
>> 3422 ret = clk_prepare_enable(host->biu_clk);
>> 3423 if (ret)
>> 3424 return ret;
>> 3425 }
>>
>> We previously assumed 'host->slot' could be null (see line 3419).
>>
>> The following situation is similar, so add a judgement.
>>
>> Signed-off-by: Pan Zhang <zhangpan26@huawei.com>
>> ---
>> drivers/mmc/host/dw_mmc.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>> index fc9d4d0..8e27c52 100644
>> --- a/drivers/mmc/host/dw_mmc.c
>> +++ b/drivers/mmc/host/dw_mmc.c
>> @@ -3454,7 +3454,7 @@ int dw_mci_runtime_resume(struct device *dev)
>> mci_writel(host, CTRL, SDMMC_CTRL_INT_ENABLE);
>>
>>
>> - if (host->slot->mmc->pm_flags & MMC_PM_KEEP_POWER)
>> + if (host->slot && (host->slot->mmc->pm_flags &
>> + MMC_PM_KEEP_POWER))
>> dw_mci_set_ios(host->slot->mmc,
>> &host->slot->mmc->ios);
>This shouldn't be a problem as the ->runtime_resume() callback can't be invoked, unless there is a slot.
>>
>> /* Force setup bus to guarantee available clock output */
>> --
>> 2.7.4
>>
If so, there is no need to assume host->slot pointer previously(line 3419)?
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: Re: [PATCH] mmc: host: fix a possible null pointer access.
2019-12-19 6:28 ` Pan Zhang
@ 2019-12-19 7:07 ` Ulf Hansson
0 siblings, 0 replies; 4+ messages in thread
From: Ulf Hansson @ 2019-12-19 7:07 UTC (permalink / raw)
To: Pan Zhang
Cc: Philipp Zabel, Jaehoon Chung, hushiyuan, linux-mmc,
Linux Kernel Mailing List
On Thu, 19 Dec 2019 at 07:28, Pan Zhang <zhangpan26@huawei.com> wrote:
>
> On Wed, 18 Dec 2019 at 7:52 p.m., Ulf Hansson <ulf.hansson@linaro.org> wrote:
> >>
> >> 3419 if (host->slot &&
> >> 3420 (mmc_can_gpio_cd(host->slot->mmc) ||
> >> 3421 !mmc_card_is_removable(host->slot->mmc))) {
> >> 3422 ret = clk_prepare_enable(host->biu_clk);
> >> 3423 if (ret)
> >> 3424 return ret;
> >> 3425 }
> >>
> >> We previously assumed 'host->slot' could be null (see line 3419).
> >>
> >> The following situation is similar, so add a judgement.
> >>
> >> Signed-off-by: Pan Zhang <zhangpan26@huawei.com>
> >> ---
> >> drivers/mmc/host/dw_mmc.c | 2 +-
> >> 1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> >> index fc9d4d0..8e27c52 100644
> >> --- a/drivers/mmc/host/dw_mmc.c
> >> +++ b/drivers/mmc/host/dw_mmc.c
> >> @@ -3454,7 +3454,7 @@ int dw_mci_runtime_resume(struct device *dev)
> >> mci_writel(host, CTRL, SDMMC_CTRL_INT_ENABLE);
> >>
> >>
> >> - if (host->slot->mmc->pm_flags & MMC_PM_KEEP_POWER)
> >> + if (host->slot && (host->slot->mmc->pm_flags &
> >> + MMC_PM_KEEP_POWER))
> >> dw_mci_set_ios(host->slot->mmc,
> >> &host->slot->mmc->ios);
>
> >This shouldn't be a problem as the ->runtime_resume() callback can't be invoked, unless there is a slot.
>
> >>
> >> /* Force setup bus to guarantee available clock output */
> >> --
> >> 2.7.4
> >>
>
> If so, there is no need to assume host->slot pointer previously(line 3419)?
>
Yeah, there is probably more cases that has unnecessary "protection".
Kind regards
Uffe
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2019-12-19 7:08 UTC | newest]
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2019-12-17 3:17 [PATCH] mmc: host: fix a possible null pointer access Pan Zhang
2019-12-18 11:52 ` Ulf Hansson
2019-12-19 6:28 ` Pan Zhang
2019-12-19 7:07 ` Ulf Hansson
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