linux-kernel - [PATCH 2/2] aio: nullify aio->ring

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Message-Id: <1384900383-22009-2-git-send-email-sasha.levin@oracle.com>
Date:	Tue, 19 Nov 2013 17:33:03 -0500
From:	Sasha Levin <sasha.levin@...cle.com>
To:	bcrl@...ck.org, viro@...iv.linux.org.uk
Cc:	linux-aio@...ck.org, linux-fsdevel@...r.kernel.org,
	linux-kernel@...r.kernel.org, Sasha Levin <sasha.levin@...cle.com>
Subject: [PATCH 2/2] aio: nullify aio->ring_pages after freeing it

After freeing ring_pages we leave it as is causing a dangling pointer. This
has already caused an issue so to help catching any issues in the future
NULL it out.

Signed-off-by: Sasha Levin <sasha.levin@...cle.com>
---
 fs/aio.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/aio.c b/fs/aio.c
index 8b387a1..d6e8467 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -251,8 +251,10 @@ static void aio_free_ring(struct kioctx *ctx)
 
 	put_aio_ring_file(ctx);
 
-	if (ctx->ring_pages && ctx->ring_pages != ctx->internal_pages)
+	if (ctx->ring_pages && ctx->ring_pages != ctx->internal_pages) {
 		kfree(ctx->ring_pages);
+		ctx->ring_pages = NULL;
+	}
 }
 
 static int aio_ring_mmap(struct file *file, struct vm_area_struct *vma)
-- 
1.7.10.4

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