In _emif_get_id(), of_get_address() may return NULL which is later
dereferenced. Fix this bug by adding NULL check.

Found by code review.

Cc: stable@vger.kernel.org
Fixes: 86a18ee21e5e ("EDAC, ti: Add support for TI keystone and DRA7xx EDAC")
Signed-off-by: Ma Ke <make24@iscas.ac.cn>
---
Changes in v3:
- added the patch operations omitted in PATCH v2 RESEND compared to PATCH 
v2. Sorry for my oversight.
Changes in v2:
- added Cc stable line.
---
 drivers/edac/ti_edac.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/edac/ti_edac.c b/drivers/edac/ti_edac.c
index 29723c9592f7..6f3da8d99eab 100644
--- a/drivers/edac/ti_edac.c
+++ b/drivers/edac/ti_edac.c
@@ -207,6 +207,9 @@ static int _emif_get_id(struct device_node *node)
 	int my_id = 0;
 
 	addrp = of_get_address(node, 0, NULL, NULL);
+	if (!addrp)
+		return -EINVAL;
+
 	my_addr = (u32)of_translate_address(node, addrp);
 
 	for_each_matching_node(np, ti_edac_of_match) {
@@ -214,6 +217,9 @@ static int _emif_get_id(struct device_node *node)
 			continue;
 
 		addrp = of_get_address(np, 0, NULL, NULL);
+		if (!addrp)
+			return -EINVAL;
+
 		addr = (u32)of_translate_address(np, addrp);
 
 		edac_printk(KERN_INFO, EDAC_MOD_NAME,
-- 
2.25.1

On 8/1/2024 23:41, Ma Ke wrote:
> In _emif_get_id(), of_get_address() may return NULL which is later
> dereferenced. Fix this bug by adding NULL check.
> 
> Found by code review.
> 
> Cc: stable@vger.kernel.org
> Fixes: 86a18ee21e5e ("EDAC, ti: Add support for TI keystone and DRA7xx EDAC")
> Signed-off-by: Ma Ke <make24@iscas.ac.cn>
> ---
> Changes in v3:
> - added the patch operations omitted in PATCH v2 RESEND compared to PATCH 
> v2. Sorry for my oversight.
> Changes in v2:
> - added Cc stable line.
> ---
>  drivers/edac/ti_edac.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/edac/ti_edac.c b/drivers/edac/ti_edac.c
> index 29723c9592f7..6f3da8d99eab 100644
> --- a/drivers/edac/ti_edac.c
> +++ b/drivers/edac/ti_edac.c
> @@ -207,6 +207,9 @@ static int _emif_get_id(struct device_node *node)
>  	int my_id = 0;
>  
>  	addrp = of_get_address(node, 0, NULL, NULL);
> +	if (!addrp)
> +		return -EINVAL;
> +
>  	my_addr = (u32)of_translate_address(node, addrp);
>  
>  	for_each_matching_node(np, ti_edac_of_match) {
> @@ -214,6 +217,9 @@ static int _emif_get_id(struct device_node *node)
>  			continue;
>  
>  		addrp = of_get_address(np, 0, NULL, NULL);
> +		if (!addrp)
> +			return -EINVAL;
> +
>  		addr = (u32)of_translate_address(np, addrp);
>  
>  		edac_printk(KERN_INFO, EDAC_MOD_NAME,

In [1], you are fixing possible NULL pointer dereferences arising from
of_get_address() and of_translate_address()
In this patch, however, you are only attempting to fix possible NULL
pointer dereferences arising from of_get_address().
Any reason why of_translate_address() doesn't need to be fixed here?

Also, since [1] and this patch are addressing possible NULL pointer
dereferences from similar functions, you may want to club them
together as a single patchset. Makes its easier for people to review.

[1]: https://lore.kernel.org/linux-edac/7021a08b-ba75-4d16-a71f-b38e48df5af3@amd.com/T/#t

-- 
Thanks,
Avadhut Naik