drivers/scsi/ses.c: eliminate double free
Julia Lawall [Wed, 10 Mar 2010 23:20:42 +0000 (15:20 -0800)]
The few lines below the kfree of hdr_buf may go to the label err_free
which will also free hdr_buf.  The most straightforward solution seems to
be to just move the kfree of hdr_buf after these gotos.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@r@
identifier E;
expression E1;
iterator I;
statement S;
@@

*kfree(E);
... when != E = E1
    when != I(E,...) S
    when != &E
*kfree(E);
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/scsi/ses.c

index 1d7a878..0d9d6f7 100644 (file)
@@ -595,8 +595,6 @@ static int ses_intf_add(struct device *cdev,
                ses_dev->page10_len = len;
                buf = NULL;
        }
-       kfree(hdr_buf);
-
        scomp = kzalloc(sizeof(struct ses_component) * components, GFP_KERNEL);
        if (!scomp)
                goto err_free;
@@ -608,6 +606,8 @@ static int ses_intf_add(struct device *cdev,
                goto err_free;
        }
 
+       kfree(hdr_buf);
+
        edev->scratch = ses_dev;
        for (i = 0; i < components; i++)
                edev->component[i].scratch = scomp + i;