Re: [PATCH] ACPI: NFIT: limit string attribute write

[Ben Dooks]

On 11/07/2023 10:22, Ben Dooks wrote:

If we're writing what could be an arbitrary sized string into an attribute
we should probably use sysfs_emit() just to be safe. Most of the other
attriubtes are some sort of integer so unlikely to be an issue so not
altered at this time.

Signed-off-by: Ben Dooks 
---
v2:
   - use sysfs_emit() instead of snprintf.
---
  drivers/acpi/nfit/core.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 9213b426b125..d7e9d9cd16d2 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -1579,7 +1579,7 @@ static ssize_t id_show(struct device *dev,
  {
struct nfit_mem *nfit_mem = to_nfit_mem(dev);
  
-	return sprintf(buf, "%s\n", nfit_mem->id);

+   return snprintf(buf, PAGE_SIZE, "%s\n", nfit_mem->id);
  }
  static DEVICE_ATTR_RO(id);
  


whoops, forgot to add before hitting ammend...

--
Ben Dooks   http://www.codethink.co.uk/
Senior Engineer Codethink - Providing Genius

https://www.codethink.co.uk/privacy.html

Re: [PATCH] ACPI: NFIT: limit string attribute write

[Ben Dooks]

On 05/07/2023 19:34, Dave Jiang wrote:



On 7/4/23 01:17, Ben Dooks wrote:
If we're writing what could be an arbitrary sized string into an 
attribute

we should probably use snprintf() just to be safe. Most of the other
attriubtes are some sort of integer so unlikely to be an issue so not
altered at this time.

Signed-off-by: Ben Dooks 
---
  drivers/acpi/nfit/core.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 9213b426b125..d7e9d9cd16d2 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -1579,7 +1579,7 @@ static ssize_t id_show(struct device *dev,
  {
  struct nfit_mem *nfit_mem = to_nfit_mem(dev);
-    return sprintf(buf, "%s\n", nfit_mem->id);
+    return snprintf(buf, PAGE_SIZE, "%s\n", nfit_mem->id);


Why not just convert it to sysfs_emit()?


I'll look into that.

--
Ben Dooks   http://www.codethink.co.uk/
Senior Engineer Codethink - Providing Genius

https://www.codethink.co.uk/privacy.html

Re: [PATCH] ACPI: NFIT: limit string attribute write

[Dave Jiang]

On 7/4/23 01:17, Ben Dooks wrote:

If we're writing what could be an arbitrary sized string into an attribute
we should probably use snprintf() just to be safe. Most of the other
attriubtes are some sort of integer so unlikely to be an issue so not
altered at this time.

Signed-off-by: Ben Dooks 
---
  drivers/acpi/nfit/core.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 9213b426b125..d7e9d9cd16d2 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -1579,7 +1579,7 @@ static ssize_t id_show(struct device *dev,
  {
struct nfit_mem *nfit_mem = to_nfit_mem(dev);
  
-	return sprintf(buf, "%s\n", nfit_mem->id);

+   return snprintf(buf, PAGE_SIZE, "%s\n", nfit_mem->id);


Why not just convert it to sysfs_emit()?


  }
  static DEVICE_ATTR_RO(id);