Ocfs2 devel - Jun 2018 - [PATCH V2] ocfs2: Fix locking for res->tracking and dlm->tracking_list

In dlm_init_lockres() we access and modify res->tracking and
dlm->tracking_list without holding dlm->track_lock. This can cause list
corruptions and can end up in kernel panic.

Fix this by locking res->tracking and dlm->tracking_list with
dlm->track_lock instead of dlm->spinlock.

Signed-off-by: Ashish Samant <ashish.samant at oracle.com>
CC: stable at vger.kernel.org
---
 fs/ocfs2/dlm/dlmmaster.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index aaca094..826f056 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -584,9 +584,9 @@ static void dlm_init_lockres(struct dlm_ctxt *dlm,
 
 	res->last_used = 0;
 
-	spin_lock(&dlm->spinlock);
+	spin_lock(&dlm->track_lock);
 	list_add_tail(&res->tracking, &dlm->tracking_list);
-	spin_unlock(&dlm->spinlock);
+	spin_unlock(&dlm->track_lock);
 
 	memset(res->lvb, 0, DLM_LVB_LEN);
 	memset(res->refmap, 0, sizeof(res->refmap));
-- 
1.9.1

Looks good to me.


On 2018/6/26 2:26, Ashish Samant wrote:
> In dlm_init_lockres() we access and modify res->tracking and
> dlm->tracking_list without holding dlm->track_lock. This can cause
list
> corruptions and can end up in kernel panic.
>
> Fix this by locking res->tracking and dlm->tracking_list with
> dlm->track_lock instead of dlm->spinlock.
Reviewed-by: Changwei Ge <ge.changwei at h3c.com>
> Signed-off-by: Ashish Samant <ashish.samant at oracle.com>
> CC: stable at vger.kernel.org
> ---
>   fs/ocfs2/dlm/dlmmaster.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
> index aaca094..826f056 100644
> --- a/fs/ocfs2/dlm/dlmmaster.c
> +++ b/fs/ocfs2/dlm/dlmmaster.c
> @@ -584,9 +584,9 @@ static void dlm_init_lockres(struct dlm_ctxt *dlm,
>   
>   	res->last_used = 0;
>   
> -	spin_lock(&dlm->spinlock);
> +	spin_lock(&dlm->track_lock);
>   	list_add_tail(&res->tracking, &dlm->tracking_list);
> -	spin_unlock(&dlm->spinlock);
> +	spin_unlock(&dlm->track_lock);
>   
>   	memset(res->lvb, 0, DLM_LVB_LEN);
>   	memset(res->refmap, 0, sizeof(res->refmap));

On 18/6/26 02:26, Ashish Samant wrote:
> In dlm_init_lockres() we access and modify res->tracking and
> dlm->tracking_list without holding dlm->track_lock. This can cause
list
> corruptions and can end up in kernel panic.
> 
> Fix this by locking res->tracking and dlm->tracking_list with
> dlm->track_lock instead of dlm->spinlock.
> 
> Signed-off-by: Ashish Samant <ashish.samant at oracle.com>
> CC: stable at vger.kernel.org
Acked-by: Joseph Qi <jiangqi903 at gmail.com>
> ---
>  fs/ocfs2/dlm/dlmmaster.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
> index aaca094..826f056 100644
> --- a/fs/ocfs2/dlm/dlmmaster.c
> +++ b/fs/ocfs2/dlm/dlmmaster.c
> @@ -584,9 +584,9 @@ static void dlm_init_lockres(struct dlm_ctxt *dlm,
>  
>  	res->last_used = 0;
>  
> -	spin_lock(&dlm->spinlock);
> +	spin_lock(&dlm->track_lock);
>  	list_add_tail(&res->tracking, &dlm->tracking_list);
> -	spin_unlock(&dlm->spinlock);
> +	spin_unlock(&dlm->track_lock);
>  
>  	memset(res->lvb, 0, DLM_LVB_LEN);
>  	memset(res->refmap, 0, sizeof(res->refmap));
>

LGTM

On 2018/6/26 2:26, Ashish Samant wrote:
> In dlm_init_lockres() we access and modify res->tracking and
> dlm->tracking_list without holding dlm->track_lock. This can cause
list
> corruptions and can end up in kernel panic.
> 
> Fix this by locking res->tracking and dlm->tracking_list with
> dlm->track_lock instead of dlm->spinlock.
> 
> Signed-off-by: Ashish Samant <ashish.samant at oracle.com>
Acked-by: Jun Piao <piaojun at huawei.com>
> CC: stable at vger.kernel.org
> ---
>  fs/ocfs2/dlm/dlmmaster.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
> index aaca094..826f056 100644
> --- a/fs/ocfs2/dlm/dlmmaster.c
> +++ b/fs/ocfs2/dlm/dlmmaster.c
> @@ -584,9 +584,9 @@ static void dlm_init_lockres(struct dlm_ctxt *dlm,
>  
>  	res->last_used = 0;
>  
> -	spin_lock(&dlm->spinlock);
> +	spin_lock(&dlm->track_lock);
>  	list_add_tail(&res->tracking, &dlm->tracking_list);
> -	spin_unlock(&dlm->spinlock);
> +	spin_unlock(&dlm->track_lock);
>  
>  	memset(res->lvb, 0, DLM_LVB_LEN);
>  	memset(res->refmap, 0, sizeof(res->refmap));
>