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* [PATCH] lib: logic_pio: Fix potential NULL pointer dereference
@ 2018-04-03 21:12 Gustavo A. R. Silva
  0 siblings, 0 replies; 4+ messages in thread
From: Gustavo A. R. Silva @ 2018-04-03 21:12 UTC (permalink / raw)
  To: Zhichang Yuan; +Cc: linux-kernel, Gustavo A. R. Silva

new_range is being dereferenced before it is null checked, hence
there is a potential null pointer dereference.

Fix this by moving the pointer dereference after new_range has
been properly null checked.

Addresses-Coverity-ID: 1466163 ("Dereference before null check")
Fixes: 0a7198426259 ("lib: Add generic PIO mapping method")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 lib/logic_pio.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/lib/logic_pio.c b/lib/logic_pio.c
index 29cedea..30dfdce 100644
--- a/lib/logic_pio.c
+++ b/lib/logic_pio.c
@@ -33,8 +33,8 @@ static DEFINE_MUTEX(io_range_mutex);
 int logic_pio_register_range(struct logic_pio_hwaddr *new_range)
 {
 	struct logic_pio_hwaddr *range;
-	resource_size_t start = new_range->hw_start;
-	resource_size_t end = new_range->hw_start + new_range->size;
+	resource_size_t start;
+	resource_size_t end;
 	resource_size_t mmio_sz = 0;
 	resource_size_t iio_sz = MMIO_UPPER_LIMIT;
 	int ret = 0;
@@ -42,6 +42,9 @@ int logic_pio_register_range(struct logic_pio_hwaddr *new_range)
 	if (!new_range || !new_range->fwnode || !new_range->size)
 		return -EINVAL;
 
+	start = new_range->hw_start;
+	end = new_range->hw_start + new_range->size;
+
 	mutex_lock(&io_range_mutex);
 	list_for_each_entry_rcu(range, &io_range_list, list) {
 		if (range->fwnode == new_range->fwnode) {
-- 
2.7.4

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

* [PATCH] lib: logic_pio: Fix potential NULL pointer dereference
@ 2018-04-03 21:15 Gustavo A. R. Silva
  2018-04-04  8:54 ` John Garry
  2018-04-04 13:43 ` Bjorn Helgaas
  0 siblings, 2 replies; 4+ messages in thread
From: Gustavo A. R. Silva @ 2018-04-03 21:15 UTC (permalink / raw)
  To: Zhichang Yuan, Gabriele Paoloni, John Garry, Bjorn Helgaas,
	Andy Shevchenko
  Cc: linux-kernel, Gustavo A. R. Silva

new_range is being dereferenced before it is null checked, hence
there is a potential null pointer dereference.

Fix this by moving the pointer dereference after new_range has
been properly null checked.

Addresses-Coverity-ID: 1466163 ("Dereference before null check")
Fixes: 0a7198426259 ("lib: Add generic PIO mapping method")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 lib/logic_pio.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/lib/logic_pio.c b/lib/logic_pio.c
index 29cedea..30dfdce 100644
--- a/lib/logic_pio.c
+++ b/lib/logic_pio.c
@@ -33,8 +33,8 @@ static DEFINE_MUTEX(io_range_mutex);
 int logic_pio_register_range(struct logic_pio_hwaddr *new_range)
 {
 	struct logic_pio_hwaddr *range;
-	resource_size_t start = new_range->hw_start;
-	resource_size_t end = new_range->hw_start + new_range->size;
+	resource_size_t start;
+	resource_size_t end;
 	resource_size_t mmio_sz = 0;
 	resource_size_t iio_sz = MMIO_UPPER_LIMIT;
 	int ret = 0;
@@ -42,6 +42,9 @@ int logic_pio_register_range(struct logic_pio_hwaddr *new_range)
 	if (!new_range || !new_range->fwnode || !new_range->size)
 		return -EINVAL;
 
+	start = new_range->hw_start;
+	end = new_range->hw_start + new_range->size;
+
 	mutex_lock(&io_range_mutex);
 	list_for_each_entry_rcu(range, &io_range_list, list) {
 		if (range->fwnode == new_range->fwnode) {
-- 
2.7.4

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

* Re: [PATCH] lib: logic_pio: Fix potential NULL pointer dereference
  2018-04-03 21:15 [PATCH] lib: logic_pio: Fix potential NULL pointer dereference Gustavo A. R. Silva
@ 2018-04-04  8:54 ` John Garry
  2018-04-04 13:43 ` Bjorn Helgaas
  1 sibling, 0 replies; 4+ messages in thread
From: John Garry @ 2018-04-04  8:54 UTC (permalink / raw)
  To: Gustavo A. R. Silva, Bjorn Helgaas, Andy Shevchenko
  Cc: linux-kernel, Gustavo A. R. Silva

On 03/04/2018 22:15, Gustavo A. R. Silva wrote:
> new_range is being dereferenced before it is null checked, hence
> there is a potential null pointer dereference.
>
> Fix this by moving the pointer dereference after new_range has
> been properly null checked.
>

Hi Gustavo,

In fact we expect new_range to never be NULL. But, if we're going to 
check, then better make sure the check is correct...

Thanks,
John

> Addresses-Coverity-ID: 1466163 ("Dereference before null check")
> Fixes: 0a7198426259 ("lib: Add generic PIO mapping method")
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

Reviewed-by: John Garry <john.garry@huawei.com>

> ---
>  lib/logic_pio.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/lib/logic_pio.c b/lib/logic_pio.c
> index 29cedea..30dfdce 100644
> --- a/lib/logic_pio.c
> +++ b/lib/logic_pio.c
> @@ -33,8 +33,8 @@ static DEFINE_MUTEX(io_range_mutex);
>  int logic_pio_register_range(struct logic_pio_hwaddr *new_range)
>  {
>  	struct logic_pio_hwaddr *range;
> -	resource_size_t start = new_range->hw_start;
> -	resource_size_t end = new_range->hw_start + new_range->size;
> +	resource_size_t start;
> +	resource_size_t end;
>  	resource_size_t mmio_sz = 0;
>  	resource_size_t iio_sz = MMIO_UPPER_LIMIT;
>  	int ret = 0;
> @@ -42,6 +42,9 @@ int logic_pio_register_range(struct logic_pio_hwaddr *new_range)
>  	if (!new_range || !new_range->fwnode || !new_range->size)
>  		return -EINVAL;
>
> +	start = new_range->hw_start;
> +	end = new_range->hw_start + new_range->size;
> +
>  	mutex_lock(&io_range_mutex);
>  	list_for_each_entry_rcu(range, &io_range_list, list) {
>  		if (range->fwnode == new_range->fwnode) {
>

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

* Re: [PATCH] lib: logic_pio: Fix potential NULL pointer dereference
  2018-04-03 21:15 [PATCH] lib: logic_pio: Fix potential NULL pointer dereference Gustavo A. R. Silva
  2018-04-04  8:54 ` John Garry
@ 2018-04-04 13:43 ` Bjorn Helgaas
  1 sibling, 0 replies; 4+ messages in thread
From: Bjorn Helgaas @ 2018-04-04 13:43 UTC (permalink / raw)
  To: Gustavo A. R. Silva
  Cc: Zhichang Yuan, Gabriele Paoloni, John Garry, Bjorn Helgaas,
	Andy Shevchenko, linux-kernel, Gustavo A. R. Silva, linux-pci

[+cc linux-pci]

On Tue, Apr 03, 2018 at 04:15:05PM -0500, Gustavo A. R. Silva wrote:
> new_range is being dereferenced before it is null checked, hence
> there is a potential null pointer dereference.
> 
> Fix this by moving the pointer dereference after new_range has
> been properly null checked.
> 
> Addresses-Coverity-ID: 1466163 ("Dereference before null check")
> Fixes: 0a7198426259 ("lib: Add generic PIO mapping method")
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

Folded into 0a7198426259 on pci/lpc, thanks!

> ---
>  lib/logic_pio.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/logic_pio.c b/lib/logic_pio.c
> index 29cedea..30dfdce 100644
> --- a/lib/logic_pio.c
> +++ b/lib/logic_pio.c
> @@ -33,8 +33,8 @@ static DEFINE_MUTEX(io_range_mutex);
>  int logic_pio_register_range(struct logic_pio_hwaddr *new_range)
>  {
>  	struct logic_pio_hwaddr *range;
> -	resource_size_t start = new_range->hw_start;
> -	resource_size_t end = new_range->hw_start + new_range->size;
> +	resource_size_t start;
> +	resource_size_t end;
>  	resource_size_t mmio_sz = 0;
>  	resource_size_t iio_sz = MMIO_UPPER_LIMIT;
>  	int ret = 0;
> @@ -42,6 +42,9 @@ int logic_pio_register_range(struct logic_pio_hwaddr *new_range)
>  	if (!new_range || !new_range->fwnode || !new_range->size)
>  		return -EINVAL;
>  
> +	start = new_range->hw_start;
> +	end = new_range->hw_start + new_range->size;
> +
>  	mutex_lock(&io_range_mutex);
>  	list_for_each_entry_rcu(range, &io_range_list, list) {
>  		if (range->fwnode == new_range->fwnode) {
> -- 
> 2.7.4
> 

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

end of thread, other threads:[~2018-04-04 13:43 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2018-04-03 21:15 [PATCH] lib: logic_pio: Fix potential NULL pointer dereference Gustavo A. R. Silva
2018-04-04  8:54 ` John Garry
2018-04-04 13:43 ` Bjorn Helgaas
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2018-04-03 21:12 Gustavo A. R. Silva

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