[PATCH 1/4] tpm: fix access attempt to an already unmapped I/O memory region

Javier Martinez Canillas
2017-12-20T11:35:48Z

The driver maps the I/O memory address to control the LPC bus CLKRUN_EN,
but on the error path the memory is accessed by the .clk_enable handler
after this was already unmapped. So only unmap the I/O memory region if
it will not be used anymore.

Also, the correct thing to do is to cleanup the resources in the inverse
order that were acquired to prevent issues like these.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
---

drivers/char/tpm/tpm_tis_core.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index c2227983ed88..3455abbb2035 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -923,7 +923,7 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,

rc = tpm_chip_register(chip);
if (rc && is_bsw())
- iounmap(priv->ilb_base_addr);
+ goto out_err;

if (chip->ops->clk_enable != NULL)
chip->ops->clk_enable(chip, false);
@@ -931,12 +931,13 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
return rc;
out_err:
tpm_tis_remove(chip);
- if (is_bsw())
- iounmap(priv->ilb_base_addr);

if (chip->ops->clk_enable != NULL)
chip->ops->clk_enable(chip, false);

+ if (is_bsw())
+ iounmap(priv->ilb_base_addr);
+
return rc;
}
EXPORT_SYMBOL_GPL(tpm_tis_core_init);
--
2.14.3