mailbox: xgene-slimpro: Fix potential NULL pointer dereference

BugLink: https://bugs.launchpad.net/bugs/1835972
commit 3512a18cbd8d09e22a790540cb9624c3c49827ba upstream.

There is a potential execution path in which function
platform_get_resource() returns NULL. If this happens,
we will end up having a NULL pointer dereference.

Fix this by replacing devm_ioremap with devm_ioremap_resource,
which has the NULL check and the memory region request.

This code was detected with the help of Coccinelle.

Cc: stable@vger.kernel.org
Fixes: f700e84f417b ("mailbox: Add support for APM X-Gene platform mailbox driver")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/drivers/mailbox/mailbox-xgene-slimpro.c b/drivers/mailbox/mailbox-xgene-slimpro.c
index a7040163dd43983d26071faec7ac9f815db9b799..b8b2b3533f466badbf0645efda9ea975c460c998 100644 (file)
--- a/drivers/mailbox/mailbox-xgene-slimpro.c
+++ b/drivers/mailbox/mailbox-xgene-slimpro.c
@@ -195,9 +195,9 @@ static int slimpro_mbox_probe(struct platform_device *pdev)
        platform_set_drvdata(pdev, ctx);
 
        regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-       mb_base = devm_ioremap(&pdev->dev, regs->start, resource_size(regs));
-       if (!mb_base)
-               return -ENOMEM;
+       mb_base = devm_ioremap_resource(&pdev->dev, regs);
+       if (IS_ERR(mb_base))
+               return PTR_ERR(mb_base);
 
        /* Setup mailbox links */
        for (i = 0; i < MBOX_CNT; i++) {