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| Started by | Maxime Ripard <maxime.ripard@free-electrons.com> |
|---|---|
| First post | 2016-10-19 16:20 +0200 |
| Last post | 2016-10-21 10:30 +0200 |
| Articles | 3 — 3 participants |
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[PATCH v2] mmc: sunxi: Prevent against null dereference for vmmc Maxime Ripard <maxime.ripard@free-electrons.com> - 2016-10-19 16:20 +0200
Re: [PATCH v2] mmc: sunxi: Prevent against null dereference for vmmc Chen-Yu Tsai <wens@csie.org> - 2016-10-21 05:00 +0200
Re: [PATCH v2] mmc: sunxi: Prevent against null dereference for vmmc Ulf Hansson <ulf.hansson@linaro.org> - 2016-10-21 10:30 +0200
| From | Maxime Ripard <maxime.ripard@free-electrons.com> |
|---|---|
| Date | 2016-10-19 16:20 +0200 |
| Subject | [PATCH v2] mmc: sunxi: Prevent against null dereference for vmmc |
| Message-ID | <stZSP-2nd-105@gated-at.bofh.it> |
VMMC is an optional regulator, which means that mmc_regulator_get_supply
will only return an error in case of a deferred probe, but not when the
regulator is not set in the DT.
However, the sunxi driver assumes that VMMC is always there, and doesn't
check the value of the regulator pointer before using it, which obviously
leads to a (close to) null pointer dereference.
Add proper checks to prevent that.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
Changes from v1:
- remove redundant error message
---
drivers/mmc/host/sunxi-mmc.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c
index c0a5c676d0e8..b1d1303389a7 100644
--- a/drivers/mmc/host/sunxi-mmc.c
+++ b/drivers/mmc/host/sunxi-mmc.c
@@ -822,10 +822,13 @@ static void sunxi_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
break;
case MMC_POWER_UP:
- host->ferror = mmc_regulator_set_ocr(mmc, mmc->supply.vmmc,
- ios->vdd);
- if (host->ferror)
- return;
+ if (!IS_ERR(mmc->supply.vmmc)) {
+ host->ferror = mmc_regulator_set_ocr(mmc,
+ mmc->supply.vmmc,
+ ios->vdd);
+ if (host->ferror)
+ return;
+ }
if (!IS_ERR(mmc->supply.vqmmc)) {
host->ferror = regulator_enable(mmc->supply.vqmmc);
@@ -847,7 +850,9 @@ static void sunxi_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
case MMC_POWER_OFF:
dev_dbg(mmc_dev(mmc), "power off!\n");
sunxi_mmc_reset_host(host);
- mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
+ if (!IS_ERR(mmc->supply.vmmc))
+ mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
+
if (!IS_ERR(mmc->supply.vqmmc) && host->vqmmc_enabled)
regulator_disable(mmc->supply.vqmmc);
host->vqmmc_enabled = false;
--
2.9.3
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| From | Chen-Yu Tsai <wens@csie.org> |
|---|---|
| Date | 2016-10-21 05:00 +0200 |
| Message-ID | <suydP-7Zt-7@gated-at.bofh.it> |
| In reply to | #1503625 |
On Wed, Oct 19, 2016 at 9:33 PM, Maxime Ripard <maxime.ripard@free-electrons.com> wrote: > VMMC is an optional regulator, which means that mmc_regulator_get_supply > will only return an error in case of a deferred probe, but not when the > regulator is not set in the DT. > > However, the sunxi driver assumes that VMMC is always there, and doesn't > check the value of the regulator pointer before using it, which obviously > leads to a (close to) null pointer dereference. > > Add proper checks to prevent that. > > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Acked-by: Chen-Yu Tsai <wens@csie.org>
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| From | Ulf Hansson <ulf.hansson@linaro.org> |
|---|---|
| Date | 2016-10-21 10:30 +0200 |
| Message-ID | <suDnb-30q-1@gated-at.bofh.it> |
| In reply to | #1503625 |
On 19 October 2016 at 15:33, Maxime Ripard
<maxime.ripard@free-electrons.com> wrote:
> VMMC is an optional regulator, which means that mmc_regulator_get_supply
> will only return an error in case of a deferred probe, but not when the
> regulator is not set in the DT.
>
> However, the sunxi driver assumes that VMMC is always there, and doesn't
> check the value of the regulator pointer before using it, which obviously
> leads to a (close to) null pointer dereference.
>
> Add proper checks to prevent that.
>
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Thanks, applied for next!
Kind regards
Uffe
>
> ---
> Changes from v1:
> - remove redundant error message
> ---
> drivers/mmc/host/sunxi-mmc.c | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c
> index c0a5c676d0e8..b1d1303389a7 100644
> --- a/drivers/mmc/host/sunxi-mmc.c
> +++ b/drivers/mmc/host/sunxi-mmc.c
> @@ -822,10 +822,13 @@ static void sunxi_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> break;
>
> case MMC_POWER_UP:
> - host->ferror = mmc_regulator_set_ocr(mmc, mmc->supply.vmmc,
> - ios->vdd);
> - if (host->ferror)
> - return;
> + if (!IS_ERR(mmc->supply.vmmc)) {
> + host->ferror = mmc_regulator_set_ocr(mmc,
> + mmc->supply.vmmc,
> + ios->vdd);
> + if (host->ferror)
> + return;
> + }
>
> if (!IS_ERR(mmc->supply.vqmmc)) {
> host->ferror = regulator_enable(mmc->supply.vqmmc);
> @@ -847,7 +850,9 @@ static void sunxi_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> case MMC_POWER_OFF:
> dev_dbg(mmc_dev(mmc), "power off!\n");
> sunxi_mmc_reset_host(host);
> - mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
> + if (!IS_ERR(mmc->supply.vmmc))
> + mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
> +
> if (!IS_ERR(mmc->supply.vqmmc) && host->vqmmc_enabled)
> regulator_disable(mmc->supply.vqmmc);
> host->vqmmc_enabled = false;
> --
> 2.9.3
>
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