linux-integrity.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH v2] char: tpm: tpm-buf: Add sanity check fallback in read helpers
@ 2025-04-10 10:34 Purva Yeshi
  2025-04-10 12:37 ` Jarkko Sakkinen
  2025-04-11  7:20 ` Stefano Garzarella
  0 siblings, 2 replies; 5+ messages in thread
From: Purva Yeshi @ 2025-04-10 10:34 UTC (permalink / raw)
  To: peterhuewe, jarkko; +Cc: jgg, linux-integrity, linux-kernel, Purva Yeshi

Fix Smatch-detected issue:

drivers/char/tpm/tpm-buf.c:208 tpm_buf_read_u8() error:
uninitialized symbol 'value'.
drivers/char/tpm/tpm-buf.c:225 tpm_buf_read_u16() error:
uninitialized symbol 'value'.
drivers/char/tpm/tpm-buf.c:242 tpm_buf_read_u32() error:
uninitialized symbol 'value'.

Zero-initialize the return values in tpm_buf_read_u8(),
tpm_buf_read_u16(), and tpm_buf_read_u32() to guard against
uninitialized data in case of a boundary overflow.

Add defensive initialization ensures the return values are
always defined, preventing undefined behavior if the unexpected
happens.

Signed-off-by: Purva Yeshi <purvayeshi550@gmail.com>
---
V1 - https://lore.kernel.org/all/20250409205536.210202-1-purvayeshi550@gmail.com/
V2 - Update commit message to clarify patch adds a sanity check

 drivers/char/tpm/tpm-buf.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c
index e49a19fea3bd..dc882fc9fa9e 100644
--- a/drivers/char/tpm/tpm-buf.c
+++ b/drivers/char/tpm/tpm-buf.c
@@ -201,7 +201,7 @@ static void tpm_buf_read(struct tpm_buf *buf, off_t *offset, size_t count, void
  */
 u8 tpm_buf_read_u8(struct tpm_buf *buf, off_t *offset)
 {
-	u8 value;
+	u8 value = 0;
 
 	tpm_buf_read(buf, offset, sizeof(value), &value);
 
@@ -218,7 +218,7 @@ EXPORT_SYMBOL_GPL(tpm_buf_read_u8);
  */
 u16 tpm_buf_read_u16(struct tpm_buf *buf, off_t *offset)
 {
-	u16 value;
+	u16 value = 0;
 
 	tpm_buf_read(buf, offset, sizeof(value), &value);
 
@@ -235,7 +235,7 @@ EXPORT_SYMBOL_GPL(tpm_buf_read_u16);
  */
 u32 tpm_buf_read_u32(struct tpm_buf *buf, off_t *offset)
 {
-	u32 value;
+	u32 value = 0;
 
 	tpm_buf_read(buf, offset, sizeof(value), &value);
 
-- 
2.34.1


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH v2] char: tpm: tpm-buf: Add sanity check fallback in read helpers
  2025-04-10 10:34 [PATCH v2] char: tpm: tpm-buf: Add sanity check fallback in read helpers Purva Yeshi
@ 2025-04-10 12:37 ` Jarkko Sakkinen
  2025-04-10 16:30   ` Purva Yeshi
  2025-04-11  7:20 ` Stefano Garzarella
  1 sibling, 1 reply; 5+ messages in thread
From: Jarkko Sakkinen @ 2025-04-10 12:37 UTC (permalink / raw)
  To: Purva Yeshi; +Cc: peterhuewe, jgg, linux-integrity, linux-kernel

On Thu, Apr 10, 2025 at 04:04:42PM +0530, Purva Yeshi wrote:
> Fix Smatch-detected issue:
> 
> drivers/char/tpm/tpm-buf.c:208 tpm_buf_read_u8() error:
> uninitialized symbol 'value'.
> drivers/char/tpm/tpm-buf.c:225 tpm_buf_read_u16() error:
> uninitialized symbol 'value'.
> drivers/char/tpm/tpm-buf.c:242 tpm_buf_read_u32() error:
> uninitialized symbol 'value'.
> 
> Zero-initialize the return values in tpm_buf_read_u8(),
> tpm_buf_read_u16(), and tpm_buf_read_u32() to guard against
> uninitialized data in case of a boundary overflow.
> 
> Add defensive initialization ensures the return values are
> always defined, preventing undefined behavior if the unexpected
> happens.
> 
> Signed-off-by: Purva Yeshi <purvayeshi550@gmail.com>
> ---
> V1 - https://lore.kernel.org/all/20250409205536.210202-1-purvayeshi550@gmail.com/
> V2 - Update commit message to clarify patch adds a sanity check
> 
>  drivers/char/tpm/tpm-buf.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c
> index e49a19fea3bd..dc882fc9fa9e 100644
> --- a/drivers/char/tpm/tpm-buf.c
> +++ b/drivers/char/tpm/tpm-buf.c
> @@ -201,7 +201,7 @@ static void tpm_buf_read(struct tpm_buf *buf, off_t *offset, size_t count, void
>   */
>  u8 tpm_buf_read_u8(struct tpm_buf *buf, off_t *offset)
>  {
> -	u8 value;
> +	u8 value = 0;
>  
>  	tpm_buf_read(buf, offset, sizeof(value), &value);
>  
> @@ -218,7 +218,7 @@ EXPORT_SYMBOL_GPL(tpm_buf_read_u8);
>   */
>  u16 tpm_buf_read_u16(struct tpm_buf *buf, off_t *offset)
>  {
> -	u16 value;
> +	u16 value = 0;
>  
>  	tpm_buf_read(buf, offset, sizeof(value), &value);
>  
> @@ -235,7 +235,7 @@ EXPORT_SYMBOL_GPL(tpm_buf_read_u16);
>   */
>  u32 tpm_buf_read_u32(struct tpm_buf *buf, off_t *offset)
>  {
> -	u32 value;
> +	u32 value = 0;
>  
>  	tpm_buf_read(buf, offset, sizeof(value), &value);
>  
> -- 
> 2.34.1
> 
> 

It's good and I think this change is appropriate overall!

Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>

BR, Jarkko

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH v2] char: tpm: tpm-buf: Add sanity check fallback in read helpers
  2025-04-10 12:37 ` Jarkko Sakkinen
@ 2025-04-10 16:30   ` Purva Yeshi
  0 siblings, 0 replies; 5+ messages in thread
From: Purva Yeshi @ 2025-04-10 16:30 UTC (permalink / raw)
  To: Jarkko Sakkinen; +Cc: peterhuewe, jgg, linux-integrity, linux-kernel

On 10/04/25 18:07, Jarkko Sakkinen wrote:
> On Thu, Apr 10, 2025 at 04:04:42PM +0530, Purva Yeshi wrote:
>> Fix Smatch-detected issue:
>>
>> drivers/char/tpm/tpm-buf.c:208 tpm_buf_read_u8() error:
>> uninitialized symbol 'value'.
>> drivers/char/tpm/tpm-buf.c:225 tpm_buf_read_u16() error:
>> uninitialized symbol 'value'.
>> drivers/char/tpm/tpm-buf.c:242 tpm_buf_read_u32() error:
>> uninitialized symbol 'value'.
>>
>> Zero-initialize the return values in tpm_buf_read_u8(),
>> tpm_buf_read_u16(), and tpm_buf_read_u32() to guard against
>> uninitialized data in case of a boundary overflow.
>>
>> Add defensive initialization ensures the return values are
>> always defined, preventing undefined behavior if the unexpected
>> happens.
>>
>> Signed-off-by: Purva Yeshi <purvayeshi550@gmail.com>
>> ---
>> V1 - https://lore.kernel.org/all/20250409205536.210202-1-purvayeshi550@gmail.com/
>> V2 - Update commit message to clarify patch adds a sanity check
>>
>>   drivers/char/tpm/tpm-buf.c | 6 +++---
>>   1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c
>> index e49a19fea3bd..dc882fc9fa9e 100644
>> --- a/drivers/char/tpm/tpm-buf.c
>> +++ b/drivers/char/tpm/tpm-buf.c
>> @@ -201,7 +201,7 @@ static void tpm_buf_read(struct tpm_buf *buf, off_t *offset, size_t count, void
>>    */
>>   u8 tpm_buf_read_u8(struct tpm_buf *buf, off_t *offset)
>>   {
>> -	u8 value;
>> +	u8 value = 0;
>>   
>>   	tpm_buf_read(buf, offset, sizeof(value), &value);
>>   
>> @@ -218,7 +218,7 @@ EXPORT_SYMBOL_GPL(tpm_buf_read_u8);
>>    */
>>   u16 tpm_buf_read_u16(struct tpm_buf *buf, off_t *offset)
>>   {
>> -	u16 value;
>> +	u16 value = 0;
>>   
>>   	tpm_buf_read(buf, offset, sizeof(value), &value);
>>   
>> @@ -235,7 +235,7 @@ EXPORT_SYMBOL_GPL(tpm_buf_read_u16);
>>    */
>>   u32 tpm_buf_read_u32(struct tpm_buf *buf, off_t *offset)
>>   {
>> -	u32 value;
>> +	u32 value = 0;
>>   
>>   	tpm_buf_read(buf, offset, sizeof(value), &value);
>>   
>> -- 
>> 2.34.1
>>
>>
> 
> It's good and I think this change is appropriate overall!
> 
> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
> 
> BR, Jarkko

Thank you for the review.

Best Regards,
Purva Yeshi

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH v2] char: tpm: tpm-buf: Add sanity check fallback in read helpers
  2025-04-10 10:34 [PATCH v2] char: tpm: tpm-buf: Add sanity check fallback in read helpers Purva Yeshi
  2025-04-10 12:37 ` Jarkko Sakkinen
@ 2025-04-11  7:20 ` Stefano Garzarella
  2025-04-11  9:01   ` Purva Yeshi
  1 sibling, 1 reply; 5+ messages in thread
From: Stefano Garzarella @ 2025-04-11  7:20 UTC (permalink / raw)
  To: Purva Yeshi; +Cc: peterhuewe, jarkko, jgg, linux-integrity, linux-kernel

On Thu, Apr 10, 2025 at 04:04:42PM +0530, Purva Yeshi wrote:
>Fix Smatch-detected issue:
>
>drivers/char/tpm/tpm-buf.c:208 tpm_buf_read_u8() error:
>uninitialized symbol 'value'.
>drivers/char/tpm/tpm-buf.c:225 tpm_buf_read_u16() error:
>uninitialized symbol 'value'.
>drivers/char/tpm/tpm-buf.c:242 tpm_buf_read_u32() error:
>uninitialized symbol 'value'.
>
>Zero-initialize the return values in tpm_buf_read_u8(),
>tpm_buf_read_u16(), and tpm_buf_read_u32() to guard against
>uninitialized data in case of a boundary overflow.
>
>Add defensive initialization ensures the return values are
>always defined, preventing undefined behavior if the unexpected
>happens.
>
>Signed-off-by: Purva Yeshi <purvayeshi550@gmail.com>
>---
>V1 - https://lore.kernel.org/all/20250409205536.210202-1-purvayeshi550@gmail.com/
>V2 - Update commit message to clarify patch adds a sanity check

LGTM!

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

>
> drivers/char/tpm/tpm-buf.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
>diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c
>index e49a19fea3bd..dc882fc9fa9e 100644
>--- a/drivers/char/tpm/tpm-buf.c
>+++ b/drivers/char/tpm/tpm-buf.c
>@@ -201,7 +201,7 @@ static void tpm_buf_read(struct tpm_buf *buf, off_t *offset, size_t count, void
>  */
> u8 tpm_buf_read_u8(struct tpm_buf *buf, off_t *offset)
> {
>-	u8 value;
>+	u8 value = 0;
>
> 	tpm_buf_read(buf, offset, sizeof(value), &value);
>
>@@ -218,7 +218,7 @@ EXPORT_SYMBOL_GPL(tpm_buf_read_u8);
>  */
> u16 tpm_buf_read_u16(struct tpm_buf *buf, off_t *offset)
> {
>-	u16 value;
>+	u16 value = 0;
>
> 	tpm_buf_read(buf, offset, sizeof(value), &value);
>
>@@ -235,7 +235,7 @@ EXPORT_SYMBOL_GPL(tpm_buf_read_u16);
>  */
> u32 tpm_buf_read_u32(struct tpm_buf *buf, off_t *offset)
> {
>-	u32 value;
>+	u32 value = 0;
>
> 	tpm_buf_read(buf, offset, sizeof(value), &value);
>
>-- 
>2.34.1
>
>


^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH v2] char: tpm: tpm-buf: Add sanity check fallback in read helpers
  2025-04-11  7:20 ` Stefano Garzarella
@ 2025-04-11  9:01   ` Purva Yeshi
  0 siblings, 0 replies; 5+ messages in thread
From: Purva Yeshi @ 2025-04-11  9:01 UTC (permalink / raw)
  To: Stefano Garzarella; +Cc: peterhuewe, jarkko, jgg, linux-integrity, linux-kernel

On 11/04/25 12:50, Stefano Garzarella wrote:
> On Thu, Apr 10, 2025 at 04:04:42PM +0530, Purva Yeshi wrote:
>> Fix Smatch-detected issue:
>>
>> drivers/char/tpm/tpm-buf.c:208 tpm_buf_read_u8() error:
>> uninitialized symbol 'value'.
>> drivers/char/tpm/tpm-buf.c:225 tpm_buf_read_u16() error:
>> uninitialized symbol 'value'.
>> drivers/char/tpm/tpm-buf.c:242 tpm_buf_read_u32() error:
>> uninitialized symbol 'value'.
>>
>> Zero-initialize the return values in tpm_buf_read_u8(),
>> tpm_buf_read_u16(), and tpm_buf_read_u32() to guard against
>> uninitialized data in case of a boundary overflow.
>>
>> Add defensive initialization ensures the return values are
>> always defined, preventing undefined behavior if the unexpected
>> happens.
>>
>> Signed-off-by: Purva Yeshi <purvayeshi550@gmail.com>
>> ---
>> V1 - https://lore.kernel.org/all/20250409205536.210202-1- 
>> purvayeshi550@gmail.com/
>> V2 - Update commit message to clarify patch adds a sanity check
> 
> LGTM!
> 
> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

Thank you for the review.

> 
>>
>> drivers/char/tpm/tpm-buf.c | 6 +++---
>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c
>> index e49a19fea3bd..dc882fc9fa9e 100644
>> --- a/drivers/char/tpm/tpm-buf.c
>> +++ b/drivers/char/tpm/tpm-buf.c
>> @@ -201,7 +201,7 @@ static void tpm_buf_read(struct tpm_buf *buf, 
>> off_t *offset, size_t count, void
>>  */
>> u8 tpm_buf_read_u8(struct tpm_buf *buf, off_t *offset)
>> {
>> -    u8 value;
>> +    u8 value = 0;
>>
>>     tpm_buf_read(buf, offset, sizeof(value), &value);
>>
>> @@ -218,7 +218,7 @@ EXPORT_SYMBOL_GPL(tpm_buf_read_u8);
>>  */
>> u16 tpm_buf_read_u16(struct tpm_buf *buf, off_t *offset)
>> {
>> -    u16 value;
>> +    u16 value = 0;
>>
>>     tpm_buf_read(buf, offset, sizeof(value), &value);
>>
>> @@ -235,7 +235,7 @@ EXPORT_SYMBOL_GPL(tpm_buf_read_u16);
>>  */
>> u32 tpm_buf_read_u32(struct tpm_buf *buf, off_t *offset)
>> {
>> -    u32 value;
>> +    u32 value = 0;
>>
>>     tpm_buf_read(buf, offset, sizeof(value), &value);
>>
>> -- 
>> 2.34.1
>>
>>
> 

Best Regards,
Purva


^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2025-04-11  9:01 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-04-10 10:34 [PATCH v2] char: tpm: tpm-buf: Add sanity check fallback in read helpers Purva Yeshi
2025-04-10 12:37 ` Jarkko Sakkinen
2025-04-10 16:30   ` Purva Yeshi
2025-04-11  7:20 ` Stefano Garzarella
2025-04-11  9:01   ` Purva Yeshi

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).