[Ocfs2-devel] [PATCH v3] ocfs2: quota_local: fix possible uninitialized-variable access in ocfs2_local_read_info()

[Ocfs2-devel] [PATCH v3] ocfs2: quota_local: fix possible uninitialized-variable access in ocfs2_local_read_info()

[Tuo Li]

A memory block is allocated through kmalloc(), and its return value is
assigned to the pointer oinfo. However, oinfo->dqi_gqinode is not
initialized but it is accessed in:
  iput(oinfo->dqi_gqinode);

To fix this possible uninitialized-variable access, assign NULL to
oinfo->dqi_gqinode, and add ocfs2_qinfo_lock_res_init()
behind the assignment in ocfs2_local_read_info(). Remove
ocfs2_qinfo_lock_res_init() in ocfs2_global_read_info().

Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Tuo Li <islituo@gmail.com>
---
v3:
* Update description.
* Assign NULL to oinfo->dqi_gqinode, and add ocfs2_qinfo_lock_res_init()
behind the assignment in ocfs2_local_read_info(). Remove
ocfs2_qinfo_lock_res_init() in ocfs2_global_read_info()
  Thank Joseph Qi for helpful advice.
v2:
* Replace kzalloc() with NULL assignment to oinfo->dqi_gqinode.
  Thank Joseph Qi for helpful advice.
---
 fs/ocfs2/quota_global.c | 1 -
 fs/ocfs2/quota_local.c  | 2 ++
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/ocfs2/quota_global.c b/fs/ocfs2/quota_global.c
index eda83487c9ec..f033de733adb 100644
--- a/fs/ocfs2/quota_global.c
+++ b/fs/ocfs2/quota_global.c
@@ -357,7 +357,6 @@ int ocfs2_global_read_info(struct super_block *sb, int type)
 	}
 	oinfo->dqi_gi.dqi_sb = sb;
 	oinfo->dqi_gi.dqi_type = type;
-	ocfs2_qinfo_lock_res_init(&oinfo->dqi_gqlock, oinfo);
 	oinfo->dqi_gi.dqi_entry_size = sizeof(struct ocfs2_global_disk_dqblk);
 	oinfo->dqi_gi.dqi_ops = &ocfs2_global_ops;
 	oinfo->dqi_gqi_bh = NULL;
diff --git a/fs/ocfs2/quota_local.c b/fs/ocfs2/quota_local.c
index b1a8b046f4c2..0e4b16d4c037 100644
--- a/fs/ocfs2/quota_local.c
+++ b/fs/ocfs2/quota_local.c
@@ -702,6 +702,8 @@ static int ocfs2_local_read_info(struct super_block *sb, int type)
 	info->dqi_priv = oinfo;
 	oinfo->dqi_type = type;
 	INIT_LIST_HEAD(&oinfo->dqi_chunk);
+	oinfo->dqi_gqinode = NULL;
+	ocfs2_qinfo_lock_res_init(&oinfo->dqi_gqlock, oinfo);
 	oinfo->dqi_rec = NULL;
 	oinfo->dqi_lqi_bh = NULL;
 	oinfo->dqi_libh = NULL;
-- 
2.25.1


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Re: [Ocfs2-devel] [PATCH v3] ocfs2: quota_local: fix possible uninitialized-variable access in ocfs2_local_read_info()

[Joseph Qi]

On 8/4/21 11:18 AM, Tuo Li wrote:
> A memory block is allocated through kmalloc(), and its return value is
> assigned to the pointer oinfo. However, oinfo->dqi_gqinode is not
> initialized but it is accessed in:
>   iput(oinfo->dqi_gqinode);
> 
> To fix this possible uninitialized-variable access, assign NULL to
> oinfo->dqi_gqinode, and add ocfs2_qinfo_lock_res_init()
> behind the assignment in ocfs2_local_read_info(). Remove
> ocfs2_qinfo_lock_res_init() in ocfs2_global_read_info().
> 

Or we can simplify the above description to:
"To fix the possible uninitialized-variable access, initialize
dqi_gqinode and dqi_gqlock first before calling
ocfs2_global_read_info()."

> Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
> Signed-off-by: Tuo Li <islituo@gmail.com>

Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
> ---
> v3:
> * Update description.
> * Assign NULL to oinfo->dqi_gqinode, and add ocfs2_qinfo_lock_res_init()
> behind the assignment in ocfs2_local_read_info(). Remove
> ocfs2_qinfo_lock_res_init() in ocfs2_global_read_info()
>   Thank Joseph Qi for helpful advice.
> v2:
> * Replace kzalloc() with NULL assignment to oinfo->dqi_gqinode.
>   Thank Joseph Qi for helpful advice.
> ---
>  fs/ocfs2/quota_global.c | 1 -
>  fs/ocfs2/quota_local.c  | 2 ++
>  2 files changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/ocfs2/quota_global.c b/fs/ocfs2/quota_global.c
> index eda83487c9ec..f033de733adb 100644
> --- a/fs/ocfs2/quota_global.c
> +++ b/fs/ocfs2/quota_global.c
> @@ -357,7 +357,6 @@ int ocfs2_global_read_info(struct super_block *sb, int type)
>  	}
>  	oinfo->dqi_gi.dqi_sb = sb;
>  	oinfo->dqi_gi.dqi_type = type;
> -	ocfs2_qinfo_lock_res_init(&oinfo->dqi_gqlock, oinfo);
>  	oinfo->dqi_gi.dqi_entry_size = sizeof(struct ocfs2_global_disk_dqblk);
>  	oinfo->dqi_gi.dqi_ops = &ocfs2_global_ops;
>  	oinfo->dqi_gqi_bh = NULL;
> diff --git a/fs/ocfs2/quota_local.c b/fs/ocfs2/quota_local.c
> index b1a8b046f4c2..0e4b16d4c037 100644
> --- a/fs/ocfs2/quota_local.c
> +++ b/fs/ocfs2/quota_local.c
> @@ -702,6 +702,8 @@ static int ocfs2_local_read_info(struct super_block *sb, int type)
>  	info->dqi_priv = oinfo;
>  	oinfo->dqi_type = type;
>  	INIT_LIST_HEAD(&oinfo->dqi_chunk);
> +	oinfo->dqi_gqinode = NULL;
> +	ocfs2_qinfo_lock_res_init(&oinfo->dqi_gqlock, oinfo);
>  	oinfo->dqi_rec = NULL;
>  	oinfo->dqi_lqi_bh = NULL;
>  	oinfo->dqi_libh = NULL;
> 

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Re: [Ocfs2-devel] [PATCH v3] ocfs2: quota_local: fix possible uninitialized-variable access in ocfs2_local_read_info()

[Joseph Qi]

Hi Andrew,
It seems you haven't picked this patch into -mm tree.
Should we resend it or it's fine now?

Thanks,
Joseph

On 8/4/21 11:26 AM, Joseph Qi wrote:
> 
> 
> On 8/4/21 11:18 AM, Tuo Li wrote:
>> A memory block is allocated through kmalloc(), and its return value is
>> assigned to the pointer oinfo. However, oinfo->dqi_gqinode is not
>> initialized but it is accessed in:
>>   iput(oinfo->dqi_gqinode);
>>
>> To fix this possible uninitialized-variable access, assign NULL to
>> oinfo->dqi_gqinode, and add ocfs2_qinfo_lock_res_init()
>> behind the assignment in ocfs2_local_read_info(). Remove
>> ocfs2_qinfo_lock_res_init() in ocfs2_global_read_info().
>>
> 
> Or we can simplify the above description to:
> "To fix the possible uninitialized-variable access, initialize
> dqi_gqinode and dqi_gqlock first before calling
> ocfs2_global_read_info()."
> 
>> Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
>> Signed-off-by: Tuo Li <islituo@gmail.com>
> 
> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
>> ---
>> v3:
>> * Update description.
>> * Assign NULL to oinfo->dqi_gqinode, and add ocfs2_qinfo_lock_res_init()
>> behind the assignment in ocfs2_local_read_info(). Remove
>> ocfs2_qinfo_lock_res_init() in ocfs2_global_read_info()
>>   Thank Joseph Qi for helpful advice.
>> v2:
>> * Replace kzalloc() with NULL assignment to oinfo->dqi_gqinode.
>>   Thank Joseph Qi for helpful advice.
>> ---
>>  fs/ocfs2/quota_global.c | 1 -
>>  fs/ocfs2/quota_local.c  | 2 ++
>>  2 files changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/fs/ocfs2/quota_global.c b/fs/ocfs2/quota_global.c
>> index eda83487c9ec..f033de733adb 100644
>> --- a/fs/ocfs2/quota_global.c
>> +++ b/fs/ocfs2/quota_global.c
>> @@ -357,7 +357,6 @@ int ocfs2_global_read_info(struct super_block *sb, int type)
>>  	}
>>  	oinfo->dqi_gi.dqi_sb = sb;
>>  	oinfo->dqi_gi.dqi_type = type;
>> -	ocfs2_qinfo_lock_res_init(&oinfo->dqi_gqlock, oinfo);
>>  	oinfo->dqi_gi.dqi_entry_size = sizeof(struct ocfs2_global_disk_dqblk);
>>  	oinfo->dqi_gi.dqi_ops = &ocfs2_global_ops;
>>  	oinfo->dqi_gqi_bh = NULL;
>> diff --git a/fs/ocfs2/quota_local.c b/fs/ocfs2/quota_local.c
>> index b1a8b046f4c2..0e4b16d4c037 100644
>> --- a/fs/ocfs2/quota_local.c
>> +++ b/fs/ocfs2/quota_local.c
>> @@ -702,6 +702,8 @@ static int ocfs2_local_read_info(struct super_block *sb, int type)
>>  	info->dqi_priv = oinfo;
>>  	oinfo->dqi_type = type;
>>  	INIT_LIST_HEAD(&oinfo->dqi_chunk);
>> +	oinfo->dqi_gqinode = NULL;
>> +	ocfs2_qinfo_lock_res_init(&oinfo->dqi_gqlock, oinfo);
>>  	oinfo->dqi_rec = NULL;
>>  	oinfo->dqi_lqi_bh = NULL;
>>  	oinfo->dqi_libh = NULL;
>>

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