diff mbox

mmc: host: fix potential null pointer dereference

Message ID 20170523234227.GA13018@embeddedgus (mailing list archive)
State New, archived
Headers show

Commit Message

Gustavo A. R. Silva May 23, 2017, 11:42 p.m. UTC
Null check at line 1165: if (mrq->cmd), implies that mrq->cmd might
be NULL.
Add null checks before dereferencing pointer mrq->cmd in order to avoid
any potential NULL pointer dereference.

Addresses-Coverity-ID: 1408740
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
---
 drivers/mmc/host/bcm2835.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

Comments

Stefan Wahren May 25, 2017, 9:12 a.m. UTC | #1
Hi Gustavo,

> "Gustavo A. R. Silva" <garsilva@embeddedor.com> hat am 24. Mai 2017 um 01:42 geschrieben:
> 
> 
> Null check at line 1165: if (mrq->cmd), implies that mrq->cmd might
> be NULL.
> Add null checks before dereferencing pointer mrq->cmd in order to avoid
> any potential NULL pointer dereference.
> 
> Addresses-Coverity-ID: 1408740
> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>

Tested-by: Stefan Wahren <stefan.wahren@i2se.com>

with a Raspberry Pi Zero.

But please change the subject to make sure it's bcm2835 related:

mmc: bcm2835: fix potential null pointer dereferences

Thanks
Stefan
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Gustavo A. R. Silva May 25, 2017, 4:46 p.m. UTC | #2
Hi Stefan,

Quoting Stefan Wahren <stefan.wahren@i2se.com>:

> Hi Gustavo,
>
>> "Gustavo A. R. Silva" <garsilva@embeddedor.com> hat am 24. Mai 2017  
>> um 01:42 geschrieben:
>>
>>
>> Null check at line 1165: if (mrq->cmd), implies that mrq->cmd might
>> be NULL.
>> Add null checks before dereferencing pointer mrq->cmd in order to avoid
>> any potential NULL pointer dereference.
>>
>> Addresses-Coverity-ID: 1408740
>> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
>
> Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
>
> with a Raspberry Pi Zero.
>
> But please change the subject to make sure it's bcm2835 related:
>
> mmc: bcm2835: fix potential null pointer dereferences
>

OK, I'll send v2 shortly.

Thank you
--
Gustavo A. R. Silva





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diff mbox

Patch

diff --git a/drivers/mmc/host/bcm2835.c b/drivers/mmc/host/bcm2835.c
index 1f343a4..abba9a2 100644
--- a/drivers/mmc/host/bcm2835.c
+++ b/drivers/mmc/host/bcm2835.c
@@ -1172,7 +1172,10 @@  static void bcm2835_request(struct mmc_host *mmc, struct mmc_request *mrq)
 	if (mrq->data && !is_power_of_2(mrq->data->blksz)) {
 		dev_err(dev, "unsupported block size (%d bytes)\n",
 			mrq->data->blksz);
-		mrq->cmd->error = -EINVAL;
+
+		if (mrq->cmd)
+			mrq->cmd->error = -EINVAL;
+
 		mmc_request_done(mmc, mrq);
 		return;
 	}
@@ -1194,7 +1197,10 @@  static void bcm2835_request(struct mmc_host *mmc, struct mmc_request *mrq)
 			readl(host->ioaddr + SDCMD) & SDCMD_CMD_MASK,
 			edm);
 		bcm2835_dumpregs(host);
-		mrq->cmd->error = -EILSEQ;
+
+		if (mrq->cmd)
+			mrq->cmd->error = -EILSEQ;
+
 		bcm2835_finish_request(host);
 		mutex_unlock(&host->mutex);
 		return;
@@ -1207,7 +1213,7 @@  static void bcm2835_request(struct mmc_host *mmc, struct mmc_request *mrq)
 			if (!host->use_busy)
 				bcm2835_finish_command(host);
 		}
-	} else if (bcm2835_send_command(host, mrq->cmd)) {
+	} else if (mrq->cmd && bcm2835_send_command(host, mrq->cmd)) {
 		if (host->data && host->dma_desc) {
 			/* DMA transfer starts now, PIO starts after irq */
 			bcm2835_start_dma(host);