Re: Possible memory leak in fs/sysfs/bin.c

[Catalin Marinas <catalin.marinas@arm.com>]

Parag Warudkar <parag.warudkar@gmail.com> wrote:
> Catalin Marinas <catalin.marinas <at> arm.com> writes:
>
>> --- a/fs/sysfs/bin.c
>> +++ b/fs/sysfs/bin.c
>> @@ -164,6 +164,7 @@ static ssize_t write(struct file *file, const char
>> __user *userbuf,
>>  	mutex_lock(&bb->mutex);
>> 
>>  	memcpy(bb->buffer, temp, count);
>> +	kfree(temp);
>
> Does the kfree() need to be inside the mutex_lock? Otherwise looks
> OK to me.

Here's the updated patch:


Free the memory allocated by memdup_user() in fs/sysfs/bin.c

Commit 1c8542c7bb replaced kmalloc() with memdup_user() in the write()
function but also dropped the kfree(temp). The memdup_user() function
allocates memory which is never freed.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---
 fs/sysfs/bin.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c
index 9345806..2524714 100644
--- a/fs/sysfs/bin.c
+++ b/fs/sysfs/bin.c
@@ -171,6 +171,7 @@ static ssize_t write(struct file *file, const char __user *userbuf,
 	if (count > 0)
 		*off = offs + count;
 
+	kfree(temp);
 	return count;
 }
 

-- 
Catalin