[PATCH] drivers/macintosh: Correct potential double free

From: Julia Lawall
Date: Mon Mar 29 2010 - 05:39:45 EST


From: Julia Lawall <julia@xxxxxxx>

The conditionals were testing different values, but then all freeing the
same one, which could result in a double free.

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

// <smpl>
@@
expression x,e;
identifier f;
iterator I;
statement S;
@@

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

Signed-off-by: Julia Lawall <julia@xxxxxxx>

---
drivers/macintosh/windfarm_pm91.c | 9 +++------
1 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/macintosh/windfarm_pm91.c b/drivers/macintosh/windfarm_pm91.c
index bea9916..3442732 100644
--- a/drivers/macintosh/windfarm_pm91.c
+++ b/drivers/macintosh/windfarm_pm91.c
@@ -687,12 +687,9 @@ static int __devexit wf_smu_remove(struct platform_device *ddev)
wf_put_control(cpufreq_clamp);

/* Destroy control loops state structures */
- if (wf_smu_slots_fans)
- kfree(wf_smu_cpu_fans);
- if (wf_smu_drive_fans)
- kfree(wf_smu_cpu_fans);
- if (wf_smu_cpu_fans)
- kfree(wf_smu_cpu_fans);
+ kfree(wf_smu_slots_fans);
+ kfree(wf_smu_drive_fans);
+ kfree(wf_smu_cpu_fans);

return 0;
}
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