LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
* [PATCH v3] drivers/soc: Remove all strcpy() uses
@ 2021-08-01 13:19 Len Baker
  2021-08-04 22:23 ` Bjorn Andersson
  2021-08-04 22:34 ` Bjorn Andersson
  0 siblings, 2 replies; 4+ messages in thread
From: Len Baker @ 2021-08-01 13:19 UTC (permalink / raw)
  To: Kees Cook, Andy Gross, Bjorn Andersson, Geert Uytterhoeven,
	Magnus Damm, Santosh Shilimkar
  Cc: Len Baker, David Laight, Robin Murphy, linux-hardening,
	linux-arm-msm, linux-kernel, linux-renesas-soc, linux-arm-kernel

strcpy() performs no bounds checking on the destination buffer. This
could result in linear overflows beyond the end of the buffer, leading
to all kinds of misbehaviors. The safe replacement is strscpy().

Moreover, when the size of the destination buffer cannot be obtained
using "sizeof", use the memcpy function instead of strscpy.

Signed-off-by: Len Baker <len.baker@gmx.com>
---
This is a task of the KSPP [1]

[1] https://github.com/KSPP/linux/issues/88

Changelog v1 -> v2
- Change the "area_name_size" variable for a shorter name (Geert
  Uytterhoeven).
- Add the "Reviewed-by: Geert Uytterhoeven" tag.
- Use the memcpy function instead of strscpy function when the
  size of the destination buffer cannot be obtained with "sizeof"
  (David Laight, Robin Murphy).

Changelog v2 -> v3
- Remove the "Reviewed-by: Geert Uytterhoeven" tag since the code
  has changed after the v1 review (use of memcpy instead of
  strscpy).

 drivers/soc/qcom/pdr_interface.c    | 13 +++++++------
 drivers/soc/renesas/r8a779a0-sysc.c |  6 ++++--
 drivers/soc/renesas/rcar-sysc.c     |  6 ++++--
 drivers/soc/ti/knav_dma.c           |  2 +-
 4 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/drivers/soc/qcom/pdr_interface.c b/drivers/soc/qcom/pdr_interface.c
index 915d5bc3d46e..cf119fde749d 100644
--- a/drivers/soc/qcom/pdr_interface.c
+++ b/drivers/soc/qcom/pdr_interface.c
@@ -131,7 +131,7 @@ static int pdr_register_listener(struct pdr_handle *pdr,
 		return ret;

 	req.enable = enable;
-	strcpy(req.service_path, pds->service_path);
+	strscpy(req.service_path, pds->service_path, sizeof(req.service_path));

 	ret = qmi_send_request(&pdr->notifier_hdl, &pds->addr,
 			       &txn, SERVREG_REGISTER_LISTENER_REQ,
@@ -257,7 +257,7 @@ static int pdr_send_indack_msg(struct pdr_handle *pdr, struct pdr_service *pds,
 		return ret;

 	req.transaction_id = tid;
-	strcpy(req.service_path, pds->service_path);
+	strscpy(req.service_path, pds->service_path, sizeof(req.service_path));

 	ret = qmi_send_request(&pdr->notifier_hdl, &pds->addr,
 			       &txn, SERVREG_SET_ACK_REQ,
@@ -406,7 +406,7 @@ static int pdr_locate_service(struct pdr_handle *pdr, struct pdr_service *pds)
 		return -ENOMEM;

 	/* Prepare req message */
-	strcpy(req.service_name, pds->service_name);
+	strscpy(req.service_name, pds->service_name, sizeof(req.service_name));
 	req.domain_offset_valid = true;
 	req.domain_offset = 0;

@@ -531,8 +531,8 @@ struct pdr_service *pdr_add_lookup(struct pdr_handle *pdr,
 		return ERR_PTR(-ENOMEM);

 	pds->service = SERVREG_NOTIFIER_SERVICE;
-	strcpy(pds->service_name, service_name);
-	strcpy(pds->service_path, service_path);
+	strscpy(pds->service_name, service_name, sizeof(pds->service_name));
+	strscpy(pds->service_path, service_path, sizeof(pds->service_path));
 	pds->need_locator_lookup = true;

 	mutex_lock(&pdr->list_lock);
@@ -587,7 +587,8 @@ int pdr_restart_pd(struct pdr_handle *pdr, struct pdr_service *pds)
 			break;

 		/* Prepare req message */
-		strcpy(req.service_path, pds->service_path);
+		strscpy(req.service_path, pds->service_path,
+			sizeof(req.service_path));
 		addr = pds->addr;
 		break;
 	}
diff --git a/drivers/soc/renesas/r8a779a0-sysc.c b/drivers/soc/renesas/r8a779a0-sysc.c
index d464ffa1be33..7410b9fa9846 100644
--- a/drivers/soc/renesas/r8a779a0-sysc.c
+++ b/drivers/soc/renesas/r8a779a0-sysc.c
@@ -404,19 +404,21 @@ static int __init r8a779a0_sysc_pd_init(void)
 	for (i = 0; i < info->num_areas; i++) {
 		const struct r8a779a0_sysc_area *area = &info->areas[i];
 		struct r8a779a0_sysc_pd *pd;
+		size_t n;

 		if (!area->name) {
 			/* Skip NULLified area */
 			continue;
 		}

-		pd = kzalloc(sizeof(*pd) + strlen(area->name) + 1, GFP_KERNEL);
+		n = strlen(area->name) + 1;
+		pd = kzalloc(sizeof(*pd) + n, GFP_KERNEL);
 		if (!pd) {
 			error = -ENOMEM;
 			goto out_put;
 		}

-		strcpy(pd->name, area->name);
+		memcpy(pd->name, area->name, n);
 		pd->genpd.name = pd->name;
 		pd->pdr = area->pdr;
 		pd->flags = area->flags;
diff --git a/drivers/soc/renesas/rcar-sysc.c b/drivers/soc/renesas/rcar-sysc.c
index 53387a72ca00..b0a80de34c98 100644
--- a/drivers/soc/renesas/rcar-sysc.c
+++ b/drivers/soc/renesas/rcar-sysc.c
@@ -396,19 +396,21 @@ static int __init rcar_sysc_pd_init(void)
 	for (i = 0; i < info->num_areas; i++) {
 		const struct rcar_sysc_area *area = &info->areas[i];
 		struct rcar_sysc_pd *pd;
+		size_t n;

 		if (!area->name) {
 			/* Skip NULLified area */
 			continue;
 		}

-		pd = kzalloc(sizeof(*pd) + strlen(area->name) + 1, GFP_KERNEL);
+		n = strlen(area->name) + 1;
+		pd = kzalloc(sizeof(*pd) + n, GFP_KERNEL);
 		if (!pd) {
 			error = -ENOMEM;
 			goto out_put;
 		}

-		strcpy(pd->name, area->name);
+		memcpy(pd->name, area->name, n);
 		pd->genpd.name = pd->name;
 		pd->ch.chan_offs = area->chan_offs;
 		pd->ch.chan_bit = area->chan_bit;
diff --git a/drivers/soc/ti/knav_dma.c b/drivers/soc/ti/knav_dma.c
index 591d14ebcb11..5f9816d317a5 100644
--- a/drivers/soc/ti/knav_dma.c
+++ b/drivers/soc/ti/knav_dma.c
@@ -691,7 +691,7 @@ static int dma_init(struct device_node *cloud, struct device_node *dma_node)
 	dma->max_rx_flow = max_rx_flow;
 	dma->max_tx_chan = min(max_tx_chan, max_tx_sched);
 	atomic_set(&dma->ref_count, 0);
-	strcpy(dma->name, node->name);
+	strscpy(dma->name, node->name, sizeof(dma->name));
 	spin_lock_init(&dma->lock);

 	for (i = 0; i < dma->max_tx_chan; i++) {
--
2.25.1


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH v3] drivers/soc: Remove all strcpy() uses
  2021-08-01 13:19 [PATCH v3] drivers/soc: Remove all strcpy() uses Len Baker
@ 2021-08-04 22:23 ` Bjorn Andersson
  2021-08-07 17:48   ` Len Baker
  2021-08-04 22:34 ` Bjorn Andersson
  1 sibling, 1 reply; 4+ messages in thread
From: Bjorn Andersson @ 2021-08-04 22:23 UTC (permalink / raw)
  To: Len Baker
  Cc: Kees Cook, Andy Gross, Geert Uytterhoeven, Magnus Damm,
	Santosh Shilimkar, David Laight, Robin Murphy, linux-hardening,
	linux-arm-msm, linux-kernel, linux-renesas-soc, linux-arm-kernel

On Sun 01 Aug 08:19 CDT 2021, Len Baker wrote:

> strcpy() performs no bounds checking on the destination buffer. This
> could result in linear overflows beyond the end of the buffer, leading
> to all kinds of misbehaviors. The safe replacement is strscpy().
> 

While this is true, are any of these uses of strcpy affected by its
shortcomings?

> Moreover, when the size of the destination buffer cannot be obtained
> using "sizeof", use the memcpy function instead of strscpy.
> 

This is not why you're using memcpy, you're using it because you _know_
how many bytes should be copied - because you just did a strlen() and
allocated that amount of space.

> Signed-off-by: Len Baker <len.baker@gmx.com>
> ---
> This is a task of the KSPP [1]
> 
> [1] https://github.com/KSPP/linux/issues/88
> 
> Changelog v1 -> v2
> - Change the "area_name_size" variable for a shorter name (Geert
>   Uytterhoeven).
> - Add the "Reviewed-by: Geert Uytterhoeven" tag.
> - Use the memcpy function instead of strscpy function when the
>   size of the destination buffer cannot be obtained with "sizeof"
>   (David Laight, Robin Murphy).
> 
> Changelog v2 -> v3
> - Remove the "Reviewed-by: Geert Uytterhoeven" tag since the code
>   has changed after the v1 review (use of memcpy instead of
>   strscpy).
> 
>  drivers/soc/qcom/pdr_interface.c    | 13 +++++++------
>  drivers/soc/renesas/r8a779a0-sysc.c |  6 ++++--
>  drivers/soc/renesas/rcar-sysc.c     |  6 ++++--
>  drivers/soc/ti/knav_dma.c           |  2 +-
>  4 files changed, 16 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/soc/qcom/pdr_interface.c b/drivers/soc/qcom/pdr_interface.c
> index 915d5bc3d46e..cf119fde749d 100644
> --- a/drivers/soc/qcom/pdr_interface.c
> +++ b/drivers/soc/qcom/pdr_interface.c
> @@ -131,7 +131,7 @@ static int pdr_register_listener(struct pdr_handle *pdr,
>  		return ret;
> 
>  	req.enable = enable;
> -	strcpy(req.service_path, pds->service_path);
> +	strscpy(req.service_path, pds->service_path, sizeof(req.service_path));
> 
>  	ret = qmi_send_request(&pdr->notifier_hdl, &pds->addr,
>  			       &txn, SERVREG_REGISTER_LISTENER_REQ,
> @@ -257,7 +257,7 @@ static int pdr_send_indack_msg(struct pdr_handle *pdr, struct pdr_service *pds,
>  		return ret;
> 
>  	req.transaction_id = tid;
> -	strcpy(req.service_path, pds->service_path);
> +	strscpy(req.service_path, pds->service_path, sizeof(req.service_path));
> 
>  	ret = qmi_send_request(&pdr->notifier_hdl, &pds->addr,
>  			       &txn, SERVREG_SET_ACK_REQ,
> @@ -406,7 +406,7 @@ static int pdr_locate_service(struct pdr_handle *pdr, struct pdr_service *pds)
>  		return -ENOMEM;
> 
>  	/* Prepare req message */
> -	strcpy(req.service_name, pds->service_name);
> +	strscpy(req.service_name, pds->service_name, sizeof(req.service_name));
>  	req.domain_offset_valid = true;
>  	req.domain_offset = 0;
> 
> @@ -531,8 +531,8 @@ struct pdr_service *pdr_add_lookup(struct pdr_handle *pdr,
>  		return ERR_PTR(-ENOMEM);
> 
>  	pds->service = SERVREG_NOTIFIER_SERVICE;
> -	strcpy(pds->service_name, service_name);
> -	strcpy(pds->service_path, service_path);
> +	strscpy(pds->service_name, service_name, sizeof(pds->service_name));
> +	strscpy(pds->service_path, service_path, sizeof(pds->service_path));
>  	pds->need_locator_lookup = true;
> 
>  	mutex_lock(&pdr->list_lock);
> @@ -587,7 +587,8 @@ int pdr_restart_pd(struct pdr_handle *pdr, struct pdr_service *pds)
>  			break;
> 
>  		/* Prepare req message */
> -		strcpy(req.service_path, pds->service_path);
> +		strscpy(req.service_path, pds->service_path,
> +			sizeof(req.service_path));

There's no need to break this line.

Thanks,
Bjorn

>  		addr = pds->addr;
>  		break;
>  	}
> diff --git a/drivers/soc/renesas/r8a779a0-sysc.c b/drivers/soc/renesas/r8a779a0-sysc.c
> index d464ffa1be33..7410b9fa9846 100644
> --- a/drivers/soc/renesas/r8a779a0-sysc.c
> +++ b/drivers/soc/renesas/r8a779a0-sysc.c
> @@ -404,19 +404,21 @@ static int __init r8a779a0_sysc_pd_init(void)
>  	for (i = 0; i < info->num_areas; i++) {
>  		const struct r8a779a0_sysc_area *area = &info->areas[i];
>  		struct r8a779a0_sysc_pd *pd;
> +		size_t n;
> 
>  		if (!area->name) {
>  			/* Skip NULLified area */
>  			continue;
>  		}
> 
> -		pd = kzalloc(sizeof(*pd) + strlen(area->name) + 1, GFP_KERNEL);
> +		n = strlen(area->name) + 1;
> +		pd = kzalloc(sizeof(*pd) + n, GFP_KERNEL);
>  		if (!pd) {
>  			error = -ENOMEM;
>  			goto out_put;
>  		}
> 
> -		strcpy(pd->name, area->name);
> +		memcpy(pd->name, area->name, n);
>  		pd->genpd.name = pd->name;
>  		pd->pdr = area->pdr;
>  		pd->flags = area->flags;
> diff --git a/drivers/soc/renesas/rcar-sysc.c b/drivers/soc/renesas/rcar-sysc.c
> index 53387a72ca00..b0a80de34c98 100644
> --- a/drivers/soc/renesas/rcar-sysc.c
> +++ b/drivers/soc/renesas/rcar-sysc.c
> @@ -396,19 +396,21 @@ static int __init rcar_sysc_pd_init(void)
>  	for (i = 0; i < info->num_areas; i++) {
>  		const struct rcar_sysc_area *area = &info->areas[i];
>  		struct rcar_sysc_pd *pd;
> +		size_t n;
> 
>  		if (!area->name) {
>  			/* Skip NULLified area */
>  			continue;
>  		}
> 
> -		pd = kzalloc(sizeof(*pd) + strlen(area->name) + 1, GFP_KERNEL);
> +		n = strlen(area->name) + 1;
> +		pd = kzalloc(sizeof(*pd) + n, GFP_KERNEL);
>  		if (!pd) {
>  			error = -ENOMEM;
>  			goto out_put;
>  		}
> 
> -		strcpy(pd->name, area->name);
> +		memcpy(pd->name, area->name, n);
>  		pd->genpd.name = pd->name;
>  		pd->ch.chan_offs = area->chan_offs;
>  		pd->ch.chan_bit = area->chan_bit;
> diff --git a/drivers/soc/ti/knav_dma.c b/drivers/soc/ti/knav_dma.c
> index 591d14ebcb11..5f9816d317a5 100644
> --- a/drivers/soc/ti/knav_dma.c
> +++ b/drivers/soc/ti/knav_dma.c
> @@ -691,7 +691,7 @@ static int dma_init(struct device_node *cloud, struct device_node *dma_node)
>  	dma->max_rx_flow = max_rx_flow;
>  	dma->max_tx_chan = min(max_tx_chan, max_tx_sched);
>  	atomic_set(&dma->ref_count, 0);
> -	strcpy(dma->name, node->name);
> +	strscpy(dma->name, node->name, sizeof(dma->name));
>  	spin_lock_init(&dma->lock);
> 
>  	for (i = 0; i < dma->max_tx_chan; i++) {
> --
> 2.25.1
> 

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH v3] drivers/soc: Remove all strcpy() uses
  2021-08-01 13:19 [PATCH v3] drivers/soc: Remove all strcpy() uses Len Baker
  2021-08-04 22:23 ` Bjorn Andersson
@ 2021-08-04 22:34 ` Bjorn Andersson
  1 sibling, 0 replies; 4+ messages in thread
From: Bjorn Andersson @ 2021-08-04 22:34 UTC (permalink / raw)
  To: Len Baker
  Cc: Kees Cook, Andy Gross, Geert Uytterhoeven, Magnus Damm,
	Santosh Shilimkar, David Laight, Robin Murphy, linux-hardening,
	linux-arm-msm, linux-kernel, linux-renesas-soc, linux-arm-kernel

On Sun 01 Aug 08:19 CDT 2021, Len Baker wrote:

> strcpy() performs no bounds checking on the destination buffer. This
> could result in linear overflows beyond the end of the buffer, leading
> to all kinds of misbehaviors. The safe replacement is strscpy().
> 
> Moreover, when the size of the destination buffer cannot be obtained
> using "sizeof", use the memcpy function instead of strscpy.
> 
> Signed-off-by: Len Baker <len.baker@gmx.com>

Forgot one thing, it's unclear who should pick this patch up and there's
definitely a chance that it will cause merge conflicts regardless of
whom of us end up picking it.

Could you please split it so that the qcom, renesas and ti pieces can be
picked up by respective maintainer?

Thanks,
Bjorn

> ---
> This is a task of the KSPP [1]
> 
> [1] https://github.com/KSPP/linux/issues/88
> 
> Changelog v1 -> v2
> - Change the "area_name_size" variable for a shorter name (Geert
>   Uytterhoeven).
> - Add the "Reviewed-by: Geert Uytterhoeven" tag.
> - Use the memcpy function instead of strscpy function when the
>   size of the destination buffer cannot be obtained with "sizeof"
>   (David Laight, Robin Murphy).
> 
> Changelog v2 -> v3
> - Remove the "Reviewed-by: Geert Uytterhoeven" tag since the code
>   has changed after the v1 review (use of memcpy instead of
>   strscpy).
> 
>  drivers/soc/qcom/pdr_interface.c    | 13 +++++++------
>  drivers/soc/renesas/r8a779a0-sysc.c |  6 ++++--
>  drivers/soc/renesas/rcar-sysc.c     |  6 ++++--
>  drivers/soc/ti/knav_dma.c           |  2 +-
>  4 files changed, 16 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/soc/qcom/pdr_interface.c b/drivers/soc/qcom/pdr_interface.c
> index 915d5bc3d46e..cf119fde749d 100644
> --- a/drivers/soc/qcom/pdr_interface.c
> +++ b/drivers/soc/qcom/pdr_interface.c
> @@ -131,7 +131,7 @@ static int pdr_register_listener(struct pdr_handle *pdr,
>  		return ret;
> 
>  	req.enable = enable;
> -	strcpy(req.service_path, pds->service_path);
> +	strscpy(req.service_path, pds->service_path, sizeof(req.service_path));
> 
>  	ret = qmi_send_request(&pdr->notifier_hdl, &pds->addr,
>  			       &txn, SERVREG_REGISTER_LISTENER_REQ,
> @@ -257,7 +257,7 @@ static int pdr_send_indack_msg(struct pdr_handle *pdr, struct pdr_service *pds,
>  		return ret;
> 
>  	req.transaction_id = tid;
> -	strcpy(req.service_path, pds->service_path);
> +	strscpy(req.service_path, pds->service_path, sizeof(req.service_path));
> 
>  	ret = qmi_send_request(&pdr->notifier_hdl, &pds->addr,
>  			       &txn, SERVREG_SET_ACK_REQ,
> @@ -406,7 +406,7 @@ static int pdr_locate_service(struct pdr_handle *pdr, struct pdr_service *pds)
>  		return -ENOMEM;
> 
>  	/* Prepare req message */
> -	strcpy(req.service_name, pds->service_name);
> +	strscpy(req.service_name, pds->service_name, sizeof(req.service_name));
>  	req.domain_offset_valid = true;
>  	req.domain_offset = 0;
> 
> @@ -531,8 +531,8 @@ struct pdr_service *pdr_add_lookup(struct pdr_handle *pdr,
>  		return ERR_PTR(-ENOMEM);
> 
>  	pds->service = SERVREG_NOTIFIER_SERVICE;
> -	strcpy(pds->service_name, service_name);
> -	strcpy(pds->service_path, service_path);
> +	strscpy(pds->service_name, service_name, sizeof(pds->service_name));
> +	strscpy(pds->service_path, service_path, sizeof(pds->service_path));
>  	pds->need_locator_lookup = true;
> 
>  	mutex_lock(&pdr->list_lock);
> @@ -587,7 +587,8 @@ int pdr_restart_pd(struct pdr_handle *pdr, struct pdr_service *pds)
>  			break;
> 
>  		/* Prepare req message */
> -		strcpy(req.service_path, pds->service_path);
> +		strscpy(req.service_path, pds->service_path,
> +			sizeof(req.service_path));
>  		addr = pds->addr;
>  		break;
>  	}
> diff --git a/drivers/soc/renesas/r8a779a0-sysc.c b/drivers/soc/renesas/r8a779a0-sysc.c
> index d464ffa1be33..7410b9fa9846 100644
> --- a/drivers/soc/renesas/r8a779a0-sysc.c
> +++ b/drivers/soc/renesas/r8a779a0-sysc.c
> @@ -404,19 +404,21 @@ static int __init r8a779a0_sysc_pd_init(void)
>  	for (i = 0; i < info->num_areas; i++) {
>  		const struct r8a779a0_sysc_area *area = &info->areas[i];
>  		struct r8a779a0_sysc_pd *pd;
> +		size_t n;
> 
>  		if (!area->name) {
>  			/* Skip NULLified area */
>  			continue;
>  		}
> 
> -		pd = kzalloc(sizeof(*pd) + strlen(area->name) + 1, GFP_KERNEL);
> +		n = strlen(area->name) + 1;
> +		pd = kzalloc(sizeof(*pd) + n, GFP_KERNEL);
>  		if (!pd) {
>  			error = -ENOMEM;
>  			goto out_put;
>  		}
> 
> -		strcpy(pd->name, area->name);
> +		memcpy(pd->name, area->name, n);
>  		pd->genpd.name = pd->name;
>  		pd->pdr = area->pdr;
>  		pd->flags = area->flags;
> diff --git a/drivers/soc/renesas/rcar-sysc.c b/drivers/soc/renesas/rcar-sysc.c
> index 53387a72ca00..b0a80de34c98 100644
> --- a/drivers/soc/renesas/rcar-sysc.c
> +++ b/drivers/soc/renesas/rcar-sysc.c
> @@ -396,19 +396,21 @@ static int __init rcar_sysc_pd_init(void)
>  	for (i = 0; i < info->num_areas; i++) {
>  		const struct rcar_sysc_area *area = &info->areas[i];
>  		struct rcar_sysc_pd *pd;
> +		size_t n;
> 
>  		if (!area->name) {
>  			/* Skip NULLified area */
>  			continue;
>  		}
> 
> -		pd = kzalloc(sizeof(*pd) + strlen(area->name) + 1, GFP_KERNEL);
> +		n = strlen(area->name) + 1;
> +		pd = kzalloc(sizeof(*pd) + n, GFP_KERNEL);
>  		if (!pd) {
>  			error = -ENOMEM;
>  			goto out_put;
>  		}
> 
> -		strcpy(pd->name, area->name);
> +		memcpy(pd->name, area->name, n);
>  		pd->genpd.name = pd->name;
>  		pd->ch.chan_offs = area->chan_offs;
>  		pd->ch.chan_bit = area->chan_bit;
> diff --git a/drivers/soc/ti/knav_dma.c b/drivers/soc/ti/knav_dma.c
> index 591d14ebcb11..5f9816d317a5 100644
> --- a/drivers/soc/ti/knav_dma.c
> +++ b/drivers/soc/ti/knav_dma.c
> @@ -691,7 +691,7 @@ static int dma_init(struct device_node *cloud, struct device_node *dma_node)
>  	dma->max_rx_flow = max_rx_flow;
>  	dma->max_tx_chan = min(max_tx_chan, max_tx_sched);
>  	atomic_set(&dma->ref_count, 0);
> -	strcpy(dma->name, node->name);
> +	strscpy(dma->name, node->name, sizeof(dma->name));
>  	spin_lock_init(&dma->lock);
> 
>  	for (i = 0; i < dma->max_tx_chan; i++) {
> --
> 2.25.1
> 

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH v3] drivers/soc: Remove all strcpy() uses
  2021-08-04 22:23 ` Bjorn Andersson
@ 2021-08-07 17:48   ` Len Baker
  0 siblings, 0 replies; 4+ messages in thread
From: Len Baker @ 2021-08-07 17:48 UTC (permalink / raw)
  To: Bjorn Andersson
  Cc: Len Baker, Kees Cook, Andy Gross, Geert Uytterhoeven,
	Magnus Damm, Santosh Shilimkar, David Laight, Robin Murphy,
	linux-hardening, linux-arm-msm, linux-kernel, linux-renesas-soc,
	linux-arm-kernel

Hi,

On Wed, Aug 04, 2021 at 05:23:54PM -0500, Bjorn Andersson wrote:
> On Sun 01 Aug 08:19 CDT 2021, Len Baker wrote:
>
> > strcpy() performs no bounds checking on the destination buffer. This
> > could result in linear overflows beyond the end of the buffer, leading
> > to all kinds of misbehaviors. The safe replacement is strscpy().
> >
>
> While this is true, are any of these uses of strcpy affected by its
> shortcomings?

No, this patch is only an effort to clean up the proliferation of str*()
functions in the kernel.

> > Moreover, when the size of the destination buffer cannot be obtained
> > using "sizeof", use the memcpy function instead of strscpy.
> >
>
> This is not why you're using memcpy, you're using it because you _know_
> how many bytes should be copied - because you just did a strlen() and
> allocated that amount of space.

Understood, I will change the commit message.

>
> > [...]
> >  		/* Prepare req message */
> > -		strcpy(req.service_path, pds->service_path);
> > +		strscpy(req.service_path, pds->service_path,
> > +			sizeof(req.service_path));
>
> There's no need to break this line.

Ok, thanks.

Regards,
Len

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2021-08-07 17:49 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-08-01 13:19 [PATCH v3] drivers/soc: Remove all strcpy() uses Len Baker
2021-08-04 22:23 ` Bjorn Andersson
2021-08-07 17:48   ` Len Baker
2021-08-04 22:34 ` Bjorn Andersson

This is a public inbox, see mirroring instructions
on how to clone and mirror all data and code used for this inbox