[patch] mailbox/tegra-hsp: Use after free in tegra_hsp_remove_doorbells()

[patch] mailbox/tegra-hsp: Use after free in tegra_hsp_remove_doorbells()

[Dan Carpenter]

We have to use the _safe version of list_for_each() because we're
freeing the pointer as we go along.  (This might not show up testing
depending on what config options you have enabled).

Fixes: ed65ee43e397 ("mailbox: Add Tegra HSP driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/mailbox/tegra-hsp.c b/drivers/mailbox/tegra-hsp.c
index 17b256a..87be8d3 100644
--- a/drivers/mailbox/tegra-hsp.c
+++ b/drivers/mailbox/tegra-hsp.c
@@ -397,12 +397,12 @@ static struct mbox_chan *of_tegra_hsp_xlate(struct mbox_controller *mbox,
 
 static void tegra_hsp_remove_doorbells(struct tegra_hsp *hsp)
 {
-	struct tegra_hsp_doorbell *db;
+	struct tegra_hsp_doorbell *db, *tmp;
 	unsigned long flags;
 
 	spin_lock_irqsave(&hsp->lock, flags);
 
-	list_for_each_entry(db, &hsp->doorbells, list)
+	list_for_each_entry_safe(db, tmp, &hsp->doorbells, list)
 		__tegra_hsp_doorbell_destroy(db);
 
 	spin_unlock_irqrestore(&hsp->lock, flags);

Re: [patch] mailbox/tegra-hsp: Use after free in tegra_hsp_remove_doorbells()

[Thierry Reding]

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On Fri, Nov 18, 2016 at 02:34:10PM +0300, Dan Carpenter wrote:
> We have to use the _safe version of list_for_each() because we're
> freeing the pointer as we go along.  (This might not show up testing
> depending on what config options you have enabled).
> 
> Fixes: ed65ee43e397 ("mailbox: Add Tegra HSP driver")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Good catch! I've applied this on top of the original driver patch that
Jassi acked earlier and I updated the Fixes: line with the new commit
SHA1.

Thanks,
Thierry

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