diff mbox

IB/hfi1: Prevent a NULL dereference

Message ID 20180109092714.valolokywtmbprw7@mwanda (mailing list archive)
State Superseded
Headers show

Commit Message

Dan Carpenter Jan. 9, 2018, 9:27 a.m. UTC
In the original code, we set "fd->uctxt" to NULL and then dereference it
which will cause an Oops.

Fixes: f2a3bc00a03c ("IB/hfi1: Protect context array set/clear with spinlock")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

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Comments

Dennis Dalessandro Jan. 9, 2018, 2:02 p.m. UTC | #1
On 1/9/2018 4:27 AM, Dan Carpenter wrote:
> In the original code, we set "fd->uctxt" to NULL and then dereference it
> which will cause an Oops.
> 
> Fixes: f2a3bc00a03c ("IB/hfi1: Protect context array set/clear with spinlock")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> 
> diff --git a/drivers/infiniband/hw/hfi1/file_ops.c b/drivers/infiniband/hw/hfi1/file_ops.c
> index 82086241aac3..3de1ac94bb85 100644
> --- a/drivers/infiniband/hw/hfi1/file_ops.c
> +++ b/drivers/infiniband/hw/hfi1/file_ops.c
> @@ -763,10 +763,10 @@ static int complete_subctxt(struct hfi1_filedata *fd)
>   	}
>   
>   	if (ret) {
> +		__clear_bit(fd->subctxt, fd->uctxt->in_use_ctxts);
>   		hfi1_rcd_put(fd->uctxt);
>   		fd->uctxt = NULL;
>   		spin_lock_irqsave(&fd->dd->uctxt_lock, flags);
> -		__clear_bit(fd->subctxt, fd->uctxt->in_use_ctxts);
>   		spin_unlock_irqrestore(&fd->dd->uctxt_lock, flags);
>   	}
>   
> 

Thanks!

Acked-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
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diff mbox

Patch

diff --git a/drivers/infiniband/hw/hfi1/file_ops.c b/drivers/infiniband/hw/hfi1/file_ops.c
index 82086241aac3..3de1ac94bb85 100644
--- a/drivers/infiniband/hw/hfi1/file_ops.c
+++ b/drivers/infiniband/hw/hfi1/file_ops.c
@@ -763,10 +763,10 @@  static int complete_subctxt(struct hfi1_filedata *fd)
 	}
 
 	if (ret) {
+		__clear_bit(fd->subctxt, fd->uctxt->in_use_ctxts);
 		hfi1_rcd_put(fd->uctxt);
 		fd->uctxt = NULL;
 		spin_lock_irqsave(&fd->dd->uctxt_lock, flags);
-		__clear_bit(fd->subctxt, fd->uctxt->in_use_ctxts);
 		spin_unlock_irqrestore(&fd->dd->uctxt_lock, flags);
 	}