Patch "IB/hfi1: Prevent a NULL dereference" has been added to the 4.14-stable tree

Patch "IB/hfi1: Prevent a NULL dereference" has been added to the 4.14-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    IB/hfi1: Prevent a NULL dereference

to the 4.14-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ib-hfi1-prevent-a-null-dereference.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 57194fa763bfa1a0908f30d4c77835beaa118fcb Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Tue, 9 Jan 2018 23:03:46 +0300
Subject: IB/hfi1: Prevent a NULL dereference

From: Dan Carpenter <dan.carpenter@oracle.com>

commit 57194fa763bfa1a0908f30d4c77835beaa118fcb upstream.

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>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/infiniband/hw/hfi1/file_ops.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/infiniband/hw/hfi1/file_ops.c
+++ b/drivers/infiniband/hw/hfi1/file_ops.c
@@ -881,11 +881,11 @@ static int complete_subctxt(struct hfi1_
 	}
 
 	if (ret) {
-		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);
+		hfi1_rcd_put(fd->uctxt);
+		fd->uctxt = NULL;
 	}
 
 	return ret;


Patches currently in stable-queue which might be from dan.carpenter@oracle.com are

queue-4.14/ib-hfi1-prevent-a-null-dereference.patch