The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertenly introduced[3] to the codebase from now on.
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo(a)embeddedor.com>
---
drivers/staging/greybus/raw.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/staging/greybus/raw.c b/drivers/staging/greybus/raw.c
index 838acbe84ca0..2b301b2aa107 100644
--- a/drivers/staging/greybus/raw.c
+++ b/drivers/staging/greybus/raw.c
@@ -30,7 +30,7 @@ struct gb_raw {
struct raw_data {
struct list_head entry;
u32 len;
- u8 data[0];
+ u8 data[];
};
static struct class *raw_class;
--
2.25.0
When we call kobject_put() and it's the last reference to the kobject
then it calls gb_audio_module_release() and frees module. We dereference
"module" on the next line which is a use after free.
Fixes: c77f85bbc91a ("greybus: audio: Fix incorrect counting of 'ida'")
Signed-off-by: Dan Carpenter <dan.carpenter(a)oracle.com>
---
drivers/staging/greybus/audio_manager.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/staging/greybus/audio_manager.c b/drivers/staging/greybus/audio_manager.c
index 9b19ea9d3fa1..9a3f7c034ab4 100644
--- a/drivers/staging/greybus/audio_manager.c
+++ b/drivers/staging/greybus/audio_manager.c
@@ -92,8 +92,8 @@ void gb_audio_manager_remove_all(void)
list_for_each_entry_safe(module, next, &modules_list, list) {
list_del(&module->list);
- kobject_put(&module->kobj);
ida_simple_remove(&module_id, module->id);
+ kobject_put(&module->kobj);
}
is_empty = list_empty(&modules_list);
--
2.11.0
From: Dan Carpenter <dan.carpenter(a)oracle.com>
[ Upstream commit 329101244f214952606359d254ae883b7109e1a5 ]
The problem is in gb_lights_request_handler(). If we get a request to
change the config then we release the light with gb_lights_light_release()
and re-allocated it. However, if the allocation fails part way through
then we call gb_lights_light_release() again. This can lead to a couple
different double frees where we haven't cleared out the original values:
gb_lights_light_v4l2_unregister(light);
...
kfree(light->channels);
kfree(light->name);
I also made a small change to how we set "light->channels_count = 0;".
The original code handled this part fine and did not cause a use after
free but it was sort of complicated to read.
Fixes: 2870b52bae4c ("greybus: lights: add lights implementation")
Signed-off-by: Dan Carpenter <dan.carpenter(a)oracle.com>
Acked-by: Rui Miguel Silva <rmfrfs(a)gmail.com>
Link: https://lore.kernel.org/r/20190829122839.GA20116@mwanda
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
drivers/staging/greybus/light.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/staging/greybus/light.c b/drivers/staging/greybus/light.c
index 9f01427f35f9..1cb82cc28aa7 100644
--- a/drivers/staging/greybus/light.c
+++ b/drivers/staging/greybus/light.c
@@ -1102,21 +1102,21 @@ static void gb_lights_channel_release(struct gb_channel *channel)
static void gb_lights_light_release(struct gb_light *light)
{
int i;
- int count;
light->ready = false;
- count = light->channels_count;
-
if (light->has_flash)
gb_lights_light_v4l2_unregister(light);
+ light->has_flash = false;
- for (i = 0; i < count; i++) {
+ for (i = 0; i < light->channels_count; i++)
gb_lights_channel_release(&light->channels[i]);
- light->channels_count--;
- }
+ light->channels_count = 0;
+
kfree(light->channels);
+ light->channels = NULL;
kfree(light->name);
+ light->name = NULL;
}
static void gb_lights_release(struct gb_lights *glights)
--
2.20.1
From: Dan Carpenter <dan.carpenter(a)oracle.com>
[ Upstream commit 329101244f214952606359d254ae883b7109e1a5 ]
The problem is in gb_lights_request_handler(). If we get a request to
change the config then we release the light with gb_lights_light_release()
and re-allocated it. However, if the allocation fails part way through
then we call gb_lights_light_release() again. This can lead to a couple
different double frees where we haven't cleared out the original values:
gb_lights_light_v4l2_unregister(light);
...
kfree(light->channels);
kfree(light->name);
I also made a small change to how we set "light->channels_count = 0;".
The original code handled this part fine and did not cause a use after
free but it was sort of complicated to read.
Fixes: 2870b52bae4c ("greybus: lights: add lights implementation")
Signed-off-by: Dan Carpenter <dan.carpenter(a)oracle.com>
Acked-by: Rui Miguel Silva <rmfrfs(a)gmail.com>
Link: https://lore.kernel.org/r/20190829122839.GA20116@mwanda
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
drivers/staging/greybus/light.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/staging/greybus/light.c b/drivers/staging/greybus/light.c
index 0f538b8c3a07..4e7575147775 100644
--- a/drivers/staging/greybus/light.c
+++ b/drivers/staging/greybus/light.c
@@ -1103,21 +1103,21 @@ static void gb_lights_channel_release(struct gb_channel *channel)
static void gb_lights_light_release(struct gb_light *light)
{
int i;
- int count;
light->ready = false;
- count = light->channels_count;
-
if (light->has_flash)
gb_lights_light_v4l2_unregister(light);
+ light->has_flash = false;
- for (i = 0; i < count; i++) {
+ for (i = 0; i < light->channels_count; i++)
gb_lights_channel_release(&light->channels[i]);
- light->channels_count--;
- }
+ light->channels_count = 0;
+
kfree(light->channels);
+ light->channels = NULL;
kfree(light->name);
+ light->name = NULL;
}
static void gb_lights_release(struct gb_lights *glights)
--
2.20.1
From: Dan Carpenter <dan.carpenter(a)oracle.com>
[ Upstream commit 329101244f214952606359d254ae883b7109e1a5 ]
The problem is in gb_lights_request_handler(). If we get a request to
change the config then we release the light with gb_lights_light_release()
and re-allocated it. However, if the allocation fails part way through
then we call gb_lights_light_release() again. This can lead to a couple
different double frees where we haven't cleared out the original values:
gb_lights_light_v4l2_unregister(light);
...
kfree(light->channels);
kfree(light->name);
I also made a small change to how we set "light->channels_count = 0;".
The original code handled this part fine and did not cause a use after
free but it was sort of complicated to read.
Fixes: 2870b52bae4c ("greybus: lights: add lights implementation")
Signed-off-by: Dan Carpenter <dan.carpenter(a)oracle.com>
Acked-by: Rui Miguel Silva <rmfrfs(a)gmail.com>
Link: https://lore.kernel.org/r/20190829122839.GA20116@mwanda
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
drivers/staging/greybus/light.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/staging/greybus/light.c b/drivers/staging/greybus/light.c
index 010ae1e9c7fb..40680eaf3974 100644
--- a/drivers/staging/greybus/light.c
+++ b/drivers/staging/greybus/light.c
@@ -1098,21 +1098,21 @@ static void gb_lights_channel_release(struct gb_channel *channel)
static void gb_lights_light_release(struct gb_light *light)
{
int i;
- int count;
light->ready = false;
- count = light->channels_count;
-
if (light->has_flash)
gb_lights_light_v4l2_unregister(light);
+ light->has_flash = false;
- for (i = 0; i < count; i++) {
+ for (i = 0; i < light->channels_count; i++)
gb_lights_channel_release(&light->channels[i]);
- light->channels_count--;
- }
+ light->channels_count = 0;
+
kfree(light->channels);
+ light->channels = NULL;
kfree(light->name);
+ light->name = NULL;
}
static void gb_lights_release(struct gb_lights *glights)
--
2.20.1
Hello,
It seems to me there is a memory leak in the implementation of gb_svc_create().
In the error handling path (labeled as err_put_device) the code
correctly puts svc->dev, but I am suspicious that svc->wq is leaking.
The allocated svc->wq needs a release via destroy_workqueue() in the
error handling path. Am I missing something?
Thank you,
--
Navid.