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From: Dan Carpenter <dan.carpenter@oracle.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org,
	"Elliott, Robert (Server Storage)" <Elliott@hp.com>
Subject: [patch -next] blk-mq: NULL dereference in __blk_mq_alloc_rq_maps()
Date: Sat, 13 Sep 2014 08:09:28 +0000	[thread overview]
Message-ID: <20140913080928.GA6469@mwanda> (raw)

We shouldn't set "set->tags" to NULL here because if we return -ENOMEM
here then we call the function a second time.  On the second time
through the loop then the statement:

	set->tags[i] = blk_mq_init_rq_map(set, i);

will Oops.  Also it is a memory leak and a layering violation.  There is
a correct call to kfree(set->tags) in blk_mq_alloc_tag_set().

Fixes: a516440542af ('blk-mq: scale depth and rq map appropriate if low on memory')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 3d863df..7e7ca57 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1961,7 +1961,6 @@ out_unwind:
 	while (--i >= 0)
 		blk_mq_free_rq_map(set, set->tags[i], i);
 
-	set->tags = NULL;
 	return -ENOMEM;
 }
 

WARNING: multiple messages have this Message-ID (diff)
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org,
	"Elliott, Robert (Server Storage)" <Elliott@hp.com>
Subject: [patch -next] blk-mq: NULL dereference in __blk_mq_alloc_rq_maps()
Date: Sat, 13 Sep 2014 11:09:28 +0300	[thread overview]
Message-ID: <20140913080928.GA6469@mwanda> (raw)

We shouldn't set "set->tags" to NULL here because if we return -ENOMEM
here then we call the function a second time.  On the second time
through the loop then the statement:

	set->tags[i] = blk_mq_init_rq_map(set, i);

will Oops.  Also it is a memory leak and a layering violation.  There is
a correct call to kfree(set->tags) in blk_mq_alloc_tag_set().

Fixes: a516440542af ('blk-mq: scale depth and rq map appropriate if low on memory')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 3d863df..7e7ca57 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1961,7 +1961,6 @@ out_unwind:
 	while (--i >= 0)
 		blk_mq_free_rq_map(set, set->tags[i], i);
 
-	set->tags = NULL;
 	return -ENOMEM;
 }
 

             reply	other threads:[~2014-09-13  8:09 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-09-13  8:09 Dan Carpenter [this message]
2014-09-13  8:09 ` [patch -next] blk-mq: NULL dereference in __blk_mq_alloc_rq_maps() Dan Carpenter

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