In capture_vma() Coverity complains of a possible buffer overrun. Even
though this is a static function where all call sites can be checked,
limiting the copy length could save some future grief.
CID 93300 (#1 of 1): Copy into fixed size buffer (STRING_OVERFLOW)
4. fixed_size_dest: You might overrun the 16-character fixed-size string c->name
by copying name without checking the length.
5. parameter_as_source: Note: This defect has an elevated risk because the
source argument is a parameter of the current function.
1326 strcpy(c->name, name);
Fix any possible overflows by using strncpy(). Zero fill the name buffer to
guarantee ASCII string NULL termination.
Cc: Jani Nikula <[email protected]>
Cc: Joonas Lahtinen <[email protected]>
Cc: Rodrigo Vivi <[email protected]>
Cc: David Airlie <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Tim Gardner <[email protected]>
---
drivers/gpu/drm/i915/i915_gpu_error.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 9cf6ac575de1..154df174e2d7 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -1297,10 +1297,11 @@ static bool record_context(struct i915_gem_context_coredump *e,
return simulated;
}
+#define VMA_NAME_LEN 16
struct intel_engine_capture_vma {
struct intel_engine_capture_vma *next;
struct i915_vma *vma;
- char name[16];
+ char name[VMA_NAME_LEN];
};
static struct intel_engine_capture_vma *
@@ -1314,7 +1315,7 @@ capture_vma(struct intel_engine_capture_vma *next,
if (!vma)
return next;
- c = kmalloc(sizeof(*c), gfp);
+ c = kzalloc(sizeof(*c), gfp);
if (!c)
return next;
@@ -1323,7 +1324,7 @@ capture_vma(struct intel_engine_capture_vma *next,
return next;
}
- strcpy(c->name, name);
+ strncpy(c->name, name, VMA_NAME_LEN-1);
c->vma = vma; /* reference held while active */
c->next = next;
--
2.33.0
On 15/09/2021 20:23, Tim Gardner wrote:
> In capture_vma() Coverity complains of a possible buffer overrun. Even
> though this is a static function where all call sites can be checked,
> limiting the copy length could save some future grief.
>
> CID 93300 (#1 of 1): Copy into fixed size buffer (STRING_OVERFLOW)
> 4. fixed_size_dest: You might overrun the 16-character fixed-size string c->name
> by copying name without checking the length.
> 5. parameter_as_source: Note: This defect has an elevated risk because the
> source argument is a parameter of the current function.
> 1326 strcpy(c->name, name);
>
> Fix any possible overflows by using strncpy(). Zero fill the name buffer to
> guarantee ASCII string NULL termination.
>
> Cc: Jani Nikula <[email protected]>
> Cc: Joonas Lahtinen <[email protected]>
> Cc: Rodrigo Vivi <[email protected]>
> Cc: David Airlie <[email protected]>
> Cc: Daniel Vetter <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Signed-off-by: Tim Gardner <[email protected]>
> ---
> drivers/gpu/drm/i915/i915_gpu_error.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
> index 9cf6ac575de1..154df174e2d7 100644
> --- a/drivers/gpu/drm/i915/i915_gpu_error.c
> +++ b/drivers/gpu/drm/i915/i915_gpu_error.c
> @@ -1297,10 +1297,11 @@ static bool record_context(struct i915_gem_context_coredump *e,
> return simulated;
> }
>
> +#define VMA_NAME_LEN 16
> struct intel_engine_capture_vma {
> struct intel_engine_capture_vma *next;
> struct i915_vma *vma;
> - char name[16];
> + char name[VMA_NAME_LEN];
> };
>
> static struct intel_engine_capture_vma *
> @@ -1314,7 +1315,7 @@ capture_vma(struct intel_engine_capture_vma *next,
> if (!vma)
> return next;
>
> - c = kmalloc(sizeof(*c), gfp);
> + c = kzalloc(sizeof(*c), gfp);
> if (!c)
> return next;
>
> @@ -1323,7 +1324,7 @@ capture_vma(struct intel_engine_capture_vma *next,
> return next;
> }
>
> - strcpy(c->name, name);
> + strncpy(c->name, name, VMA_NAME_LEN-1);
GCC is supposed to catch any problems here as you say in the commit message.
But to fix I suggest a single line change to strlcpy(c->name, name,
sizeof(c->name)) which always null terminates as bonus.
Probably same in i915_vma_coredump_create() which with strncpy would
have a theoretical chance of attempting to copy over a
non-null-terminated string.
Regards,
Tvrtko
> c->vma = vma; /* reference held while active */
>
> c->next = next;
>
On Thu, 16 Sep 2021, Tvrtko Ursulin <[email protected]> wrote:
> On 15/09/2021 20:23, Tim Gardner wrote:
>> In capture_vma() Coverity complains of a possible buffer overrun. Even
>> though this is a static function where all call sites can be checked,
>> limiting the copy length could save some future grief.
>>
>> CID 93300 (#1 of 1): Copy into fixed size buffer (STRING_OVERFLOW)
>> 4. fixed_size_dest: You might overrun the 16-character fixed-size string c->name
>> by copying name without checking the length.
>> 5. parameter_as_source: Note: This defect has an elevated risk because the
>> source argument is a parameter of the current function.
>> 1326 strcpy(c->name, name);
>>
>> Fix any possible overflows by using strncpy(). Zero fill the name buffer to
>> guarantee ASCII string NULL termination.
>>
>> Cc: Jani Nikula <[email protected]>
>> Cc: Joonas Lahtinen <[email protected]>
>> Cc: Rodrigo Vivi <[email protected]>
>> Cc: David Airlie <[email protected]>
>> Cc: Daniel Vetter <[email protected]>
>> Cc: [email protected]
>> Cc: [email protected]
>> Cc: [email protected]
>> Signed-off-by: Tim Gardner <[email protected]>
>> ---
>> drivers/gpu/drm/i915/i915_gpu_error.c | 7 ++++---
>> 1 file changed, 4 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
>> index 9cf6ac575de1..154df174e2d7 100644
>> --- a/drivers/gpu/drm/i915/i915_gpu_error.c
>> +++ b/drivers/gpu/drm/i915/i915_gpu_error.c
>> @@ -1297,10 +1297,11 @@ static bool record_context(struct i915_gem_context_coredump *e,
>> return simulated;
>> }
>>
>> +#define VMA_NAME_LEN 16
>> struct intel_engine_capture_vma {
>> struct intel_engine_capture_vma *next;
>> struct i915_vma *vma;
>> - char name[16];
>> + char name[VMA_NAME_LEN];
>> };
>>
>> static struct intel_engine_capture_vma *
>> @@ -1314,7 +1315,7 @@ capture_vma(struct intel_engine_capture_vma *next,
>> if (!vma)
>> return next;
>>
>> - c = kmalloc(sizeof(*c), gfp);
>> + c = kzalloc(sizeof(*c), gfp);
>> if (!c)
>> return next;
>>
>> @@ -1323,7 +1324,7 @@ capture_vma(struct intel_engine_capture_vma *next,
>> return next;
>> }
>>
>> - strcpy(c->name, name);
>> + strncpy(c->name, name, VMA_NAME_LEN-1);
>
> GCC is supposed to catch any problems here as you say in the commit message.
>
> But to fix I suggest a single line change to strlcpy(c->name, name,
> sizeof(c->name)) which always null terminates as bonus.
strscpy() is preferred over both strncpy() and strlcpy(). :)
BR,
Jani.
>
> Probably same in i915_vma_coredump_create() which with strncpy would
> have a theoretical chance of attempting to copy over a
> non-null-terminated string.
>
> Regards,
>
> Tvrtko
>
>> c->vma = vma; /* reference held while active */
>>
>> c->next = next;
>>
--
Jani Nikula, Intel Open Source Graphics Center
On 9/16/21 4:43 AM, Jani Nikula wrote:
> On Thu, 16 Sep 2021, Tvrtko Ursulin <[email protected]> wrote:
>> On 15/09/2021 20:23, Tim Gardner wrote:
>>> In capture_vma() Coverity complains of a possible buffer overrun. Even
>>> though this is a static function where all call sites can be checked,
>>> limiting the copy length could save some future grief.
>>>
>>> CID 93300 (#1 of 1): Copy into fixed size buffer (STRING_OVERFLOW)
>>> 4. fixed_size_dest: You might overrun the 16-character fixed-size string c->name
>>> by copying name without checking the length.
>>> 5. parameter_as_source: Note: This defect has an elevated risk because the
>>> source argument is a parameter of the current function.
>>> 1326 strcpy(c->name, name);
>>>
>>> Fix any possible overflows by using strncpy(). Zero fill the name buffer to
>>> guarantee ASCII string NULL termination.
>>>
>>> Cc: Jani Nikula <[email protected]>
>>> Cc: Joonas Lahtinen <[email protected]>
>>> Cc: Rodrigo Vivi <[email protected]>
>>> Cc: David Airlie <[email protected]>
>>> Cc: Daniel Vetter <[email protected]>
>>> Cc: [email protected]
>>> Cc: [email protected]
>>> Cc: [email protected]
>>> Signed-off-by: Tim Gardner <[email protected]>
>>> ---
>>> drivers/gpu/drm/i915/i915_gpu_error.c | 7 ++++---
>>> 1 file changed, 4 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
>>> index 9cf6ac575de1..154df174e2d7 100644
>>> --- a/drivers/gpu/drm/i915/i915_gpu_error.c
>>> +++ b/drivers/gpu/drm/i915/i915_gpu_error.c
>>> @@ -1297,10 +1297,11 @@ static bool record_context(struct i915_gem_context_coredump *e,
>>> return simulated;
>>> }
>>>
>>> +#define VMA_NAME_LEN 16
>>> struct intel_engine_capture_vma {
>>> struct intel_engine_capture_vma *next;
>>> struct i915_vma *vma;
>>> - char name[16];
>>> + char name[VMA_NAME_LEN];
>>> };
>>>
>>> static struct intel_engine_capture_vma *
>>> @@ -1314,7 +1315,7 @@ capture_vma(struct intel_engine_capture_vma *next,
>>> if (!vma)
>>> return next;
>>>
>>> - c = kmalloc(sizeof(*c), gfp);
>>> + c = kzalloc(sizeof(*c), gfp);
>>> if (!c)
>>> return next;
>>>
>>> @@ -1323,7 +1324,7 @@ capture_vma(struct intel_engine_capture_vma *next,
>>> return next;
>>> }
>>>
>>> - strcpy(c->name, name);
>>> + strncpy(c->name, name, VMA_NAME_LEN-1);
>>
>> GCC is supposed to catch any problems here as you say in the commit message.
>>
>> But to fix I suggest a single line change to strlcpy(c->name, name,
>> sizeof(c->name)) which always null terminates as bonus.
>
> strscpy() is preferred over both strncpy() and strlcpy(). :)
>
> BR,
> Jani.
>
Good call. v2 on the way.
rtg
>>
>> Probably same in i915_vma_coredump_create() which with strncpy would
>> have a theoretical chance of attempting to copy over a
>> non-null-terminated string.
>>
>> Regards,
>>
>> Tvrtko
>>
>>> c->vma = vma; /* reference held while active */
>>>
>>> c->next = next;
>>>
>
--
-----------
Tim Gardner
Canonical, Inc
In capture_vma() Coverity complains of a possible buffer overrun. Even
though this is a static function where all call sites can be checked,
limiting the copy length could save some future grief.
CID 93300 (#1 of 1): Copy into fixed size buffer (STRING_OVERFLOW)
4. fixed_size_dest: You might overrun the 16-character fixed-size string c->name
by copying name without checking the length.
5. parameter_as_source: Note: This defect has an elevated risk because the
source argument is a parameter of the current function.
1326 strcpy(c->name, name);
Fix any possible overflows by using strscpy() which guarantees NULL termination.
Also correct 2 other strcpy() call sites with the same potential for Coverity
warnings or overruns.
v2 - Change $SUBJECT from "drm/i915: zero fill vma name buffer"
Use strscpy() instead of strncpy(). Its a much simpler change.
Cc: Jani Nikula <[email protected]>
Cc: Joonas Lahtinen <[email protected]>
Cc: Rodrigo Vivi <[email protected]>
Cc: David Airlie <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Tim Gardner <[email protected]>
---
drivers/gpu/drm/i915/i915_gpu_error.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 9cf6ac575de1..7f246f51959d 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -1015,7 +1015,7 @@ i915_vma_coredump_create(const struct intel_gt *gt,
return NULL;
}
- strcpy(dst->name, name);
+ strscpy(dst->name, name, sizeof(dst->name));
dst->next = NULL;
dst->gtt_offset = vma->node.start;
@@ -1279,7 +1279,7 @@ static bool record_context(struct i915_gem_context_coredump *e,
rcu_read_lock();
task = pid_task(ctx->pid, PIDTYPE_PID);
if (task) {
- strcpy(e->comm, task->comm);
+ strscpy(e->comm, task->comm, sizeof(e->comm));
e->pid = task->pid;
}
rcu_read_unlock();
@@ -1323,7 +1323,7 @@ capture_vma(struct intel_engine_capture_vma *next,
return next;
}
- strcpy(c->name, name);
+ strscpy(c->name, name, sizeof(c->name));
c->vma = vma; /* reference held while active */
c->next = next;
--
2.33.0
On 16/09/2021 13:26, Tim Gardner wrote:
> In capture_vma() Coverity complains of a possible buffer overrun. Even
> though this is a static function where all call sites can be checked,
> limiting the copy length could save some future grief.
>
> CID 93300 (#1 of 1): Copy into fixed size buffer (STRING_OVERFLOW)
> 4. fixed_size_dest: You might overrun the 16-character fixed-size string c->name
> by copying name without checking the length.
> 5. parameter_as_source: Note: This defect has an elevated risk because the
> source argument is a parameter of the current function.
> 1326 strcpy(c->name, name);
>
> Fix any possible overflows by using strscpy() which guarantees NULL termination.
>
> Also correct 2 other strcpy() call sites with the same potential for Coverity
> warnings or overruns.
>
> v2 - Change $SUBJECT from "drm/i915: zero fill vma name buffer"
> Use strscpy() instead of strncpy(). Its a much simpler change.
>
> Cc: Jani Nikula <[email protected]>
> Cc: Joonas Lahtinen <[email protected]>
> Cc: Rodrigo Vivi <[email protected]>
> Cc: David Airlie <[email protected]>
> Cc: Daniel Vetter <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Signed-off-by: Tim Gardner <[email protected]>
> ---
> drivers/gpu/drm/i915/i915_gpu_error.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
> index 9cf6ac575de1..7f246f51959d 100644
> --- a/drivers/gpu/drm/i915/i915_gpu_error.c
> +++ b/drivers/gpu/drm/i915/i915_gpu_error.c
> @@ -1015,7 +1015,7 @@ i915_vma_coredump_create(const struct intel_gt *gt,
> return NULL;
> }
>
> - strcpy(dst->name, name);
> + strscpy(dst->name, name, sizeof(dst->name));
> dst->next = NULL;
>
> dst->gtt_offset = vma->node.start;
> @@ -1279,7 +1279,7 @@ static bool record_context(struct i915_gem_context_coredump *e,
> rcu_read_lock();
> task = pid_task(ctx->pid, PIDTYPE_PID);
> if (task) {
> - strcpy(e->comm, task->comm);
> + strscpy(e->comm, task->comm, sizeof(e->comm));
> e->pid = task->pid;
> }
> rcu_read_unlock();
> @@ -1323,7 +1323,7 @@ capture_vma(struct intel_engine_capture_vma *next,
> return next;
> }
>
> - strcpy(c->name, name);
> + strscpy(c->name, name, sizeof(c->name));
> c->vma = vma; /* reference held while active */
>
> c->next = next;
>
Reviewed-by: Tvrtko Ursulin <[email protected]>
Regards,
Tvrtko