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* [PATCH v2] drivers/soc: Remove all strcpy() uses
@ 2021-07-31 17:18 Len Baker
  2021-08-01  8:47 ` Len Baker
  0 siblings, 1 reply; 2+ messages in thread
From: Len Baker @ 2021-07-31 17:18 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.

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
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).

 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] 2+ messages in thread

* Re: [PATCH v2] drivers/soc: Remove all strcpy() uses
  2021-07-31 17:18 [PATCH v2] drivers/soc: Remove all strcpy() uses Len Baker
@ 2021-08-01  8:47 ` Len Baker
  0 siblings, 0 replies; 2+ messages in thread
From: Len Baker @ 2021-08-01  8:47 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

On Sat, Jul 31, 2021 at 07:18:25PM +0200, 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.
>
> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
> Signed-off-by: Len Baker <len.baker@gmx.com>

Drop this patch. It has errors. Sorry for the noise.

Apologies,
Len

^ permalink raw reply	[flat|nested] 2+ messages in thread

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