diff mbox series

[v3,02/11] coresight: etm4x: Fix input validation for sysfs.

Message ID 20191015212004.24748-3-mike.leach@linaro.org
State Accepted
Commit 2fe6899e36aa174abefd017887f9cfe0cb60c43a
Headers show
Series None | expand

Commit Message

Mike Leach Oct. 15, 2019, 9:19 p.m. UTC
A number of issues are fixed relating to sysfs input validation:-

1) bb_ctrl_store() - incorrect compare of bit select field to absolute
value. Reworked per ETMv4 specification.
2) seq_event_store() - incorrect mask value - register has two
event values.
3) cyc_threshold_store() - must mask with max before checking min
otherwise wrapped values can set illegal value below min.
4) res_ctrl_store() - update to mask off all res0 bits.

Reviewed-by: Leo Yan <leo.yan@linaro.org>

Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>

Signed-off-by: Mike Leach <mike.leach@linaro.org>

Fixes: a77de2637c9eb ("coresight: etm4x: moving sysFS entries to a dedicated file")
Cc: stable <stable@vger.kernel.org> # 4.9+
---
 .../coresight/coresight-etm4x-sysfs.c         | 21 ++++++++++++-------
 1 file changed, 13 insertions(+), 8 deletions(-)

-- 
2.17.1

Comments

Mathieu Poirier Oct. 17, 2019, 5:56 p.m. UTC | #1
On Tue, Oct 15, 2019 at 10:19:55PM +0100, Mike Leach wrote:
> A number of issues are fixed relating to sysfs input validation:-

> 

> 1) bb_ctrl_store() - incorrect compare of bit select field to absolute

> value. Reworked per ETMv4 specification.

> 2) seq_event_store() - incorrect mask value - register has two

> event values.

> 3) cyc_threshold_store() - must mask with max before checking min

> otherwise wrapped values can set illegal value below min.

> 4) res_ctrl_store() - update to mask off all res0 bits.

> 

> Reviewed-by: Leo Yan <leo.yan@linaro.org>

> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>

> Signed-off-by: Mike Leach <mike.leach@linaro.org>

> Fixes: a77de2637c9eb ("coresight: etm4x: moving sysFS entries to a dedicated file")

> Cc: stable <stable@vger.kernel.org> # 4.9+

> ---

>  .../coresight/coresight-etm4x-sysfs.c         | 21 ++++++++++++-------

>  1 file changed, 13 insertions(+), 8 deletions(-)

> 

> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c

> index b6984be0c515..cc8156318018 100644

> --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c

> +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c

> @@ -652,10 +652,13 @@ static ssize_t cyc_threshold_store(struct device *dev,

>  

>  	if (kstrtoul(buf, 16, &val))

>  		return -EINVAL;

> +

> +	/* mask off max threshold before checking min value */

> +	val &= ETM_CYC_THRESHOLD_MASK;

>  	if (val < drvdata->ccitmin)

>  		return -EINVAL;

>  

> -	config->ccctlr = val & ETM_CYC_THRESHOLD_MASK;

> +	config->ccctlr = val;

>  	return size;

>  }

>  static DEVICE_ATTR_RW(cyc_threshold);

> @@ -686,14 +689,16 @@ static ssize_t bb_ctrl_store(struct device *dev,

>  		return -EINVAL;

>  	if (!drvdata->nr_addr_cmp)

>  		return -EINVAL;

> +

>  	/*

> -	 * Bit[7:0] selects which address range comparator is used for

> -	 * branch broadcast control.

> +	 * Bit[8] controls include(1) / exclude(0), bits[0-7] select

> +	 * individual range comparators. If include then at least 1

> +	 * range must be selected.

>  	 */

> -	if (BMVAL(val, 0, 7) > drvdata->nr_addr_cmp)

> +	if ((val & BIT(8)) && (BMVAL(val, 0, 7) == 0))

>  		return -EINVAL;

>  

> -	config->bb_ctrl = val;

> +	config->bb_ctrl = val & GENMASK(8, 0);

>  	return size;

>  }

>  static DEVICE_ATTR_RW(bb_ctrl);

> @@ -1324,8 +1329,8 @@ static ssize_t seq_event_store(struct device *dev,

>  

>  	spin_lock(&drvdata->spinlock);

>  	idx = config->seq_idx;

> -	/* RST, bits[7:0] */

> -	config->seq_ctrl[idx] = val & 0xFF;

> +	/* Seq control has two masks B[15:8] F[7:0] */

> +	config->seq_ctrl[idx] = val & 0xFFFF;

>  	spin_unlock(&drvdata->spinlock);

>  	return size;

>  }

> @@ -1580,7 +1585,7 @@ static ssize_t res_ctrl_store(struct device *dev,

>  	if (idx % 2 != 0)

>  		/* PAIRINV, bit[21] */

>  		val &= ~BIT(21);

> -	config->res_ctrl[idx] = val;

> +	config->res_ctrl[idx] = val & GENMASK(21, 0);

>  	spin_unlock(&drvdata->spinlock);

>  	return size;


This one too, no need to send again.

>  }

> -- 

> 2.17.1

>
diff mbox series

Patch

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
index b6984be0c515..cc8156318018 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
@@ -652,10 +652,13 @@  static ssize_t cyc_threshold_store(struct device *dev,
 
 	if (kstrtoul(buf, 16, &val))
 		return -EINVAL;
+
+	/* mask off max threshold before checking min value */
+	val &= ETM_CYC_THRESHOLD_MASK;
 	if (val < drvdata->ccitmin)
 		return -EINVAL;
 
-	config->ccctlr = val & ETM_CYC_THRESHOLD_MASK;
+	config->ccctlr = val;
 	return size;
 }
 static DEVICE_ATTR_RW(cyc_threshold);
@@ -686,14 +689,16 @@  static ssize_t bb_ctrl_store(struct device *dev,
 		return -EINVAL;
 	if (!drvdata->nr_addr_cmp)
 		return -EINVAL;
+
 	/*
-	 * Bit[7:0] selects which address range comparator is used for
-	 * branch broadcast control.
+	 * Bit[8] controls include(1) / exclude(0), bits[0-7] select
+	 * individual range comparators. If include then at least 1
+	 * range must be selected.
 	 */
-	if (BMVAL(val, 0, 7) > drvdata->nr_addr_cmp)
+	if ((val & BIT(8)) && (BMVAL(val, 0, 7) == 0))
 		return -EINVAL;
 
-	config->bb_ctrl = val;
+	config->bb_ctrl = val & GENMASK(8, 0);
 	return size;
 }
 static DEVICE_ATTR_RW(bb_ctrl);
@@ -1324,8 +1329,8 @@  static ssize_t seq_event_store(struct device *dev,
 
 	spin_lock(&drvdata->spinlock);
 	idx = config->seq_idx;
-	/* RST, bits[7:0] */
-	config->seq_ctrl[idx] = val & 0xFF;
+	/* Seq control has two masks B[15:8] F[7:0] */
+	config->seq_ctrl[idx] = val & 0xFFFF;
 	spin_unlock(&drvdata->spinlock);
 	return size;
 }
@@ -1580,7 +1585,7 @@  static ssize_t res_ctrl_store(struct device *dev,
 	if (idx % 2 != 0)
 		/* PAIRINV, bit[21] */
 		val &= ~BIT(21);
-	config->res_ctrl[idx] = val;
+	config->res_ctrl[idx] = val & GENMASK(21, 0);
 	spin_unlock(&drvdata->spinlock);
 	return size;
 }