Re: [PATCH] staging: rts5208: add check on NULL before dereference

[okaya]

On 2018-06-09 12:38, Anton Vasilyev wrote:
If rtsx_probe fails to allocate dev->chip, then NULL pointer
dereference occurs at rtsx_release_resources().
Patch adds checks chip on NULL before its dereference at
rtsx_release_resources and passing with dereference inside
rtsx_release_chip.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Anton Vasilyev <vasil...@ispras.ru>
---
 drivers/staging/rts5208/rtsx.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/rts5208/rtsx.c 
b/drivers/staging/rts5208/rtsx.c
index 70e0b8623110..952dd0d580cf 100644
--- a/drivers/staging/rts5208/rtsx.c
+++ b/drivers/staging/rts5208/rtsx.c
@@ -623,12 +623,13 @@ static void rtsx_release_resources(struct 
rtsx_dev *dev)


I think you should bail out if dev->chip is null rather than adding 
conditiinals.


        if (dev->irq > 0)
                free_irq(dev->irq, (void *)dev);
-       if (dev->chip->msi_en)
+       if (dev->chip && dev->chip->msi_en)
                pci_disable_msi(dev->pci);
        if (dev->remap_addr)
                iounmap(dev->remap_addr);
+       if (dev->chip)
+               rtsx_release_chip(dev->chip);

-       rtsx_release_chip(dev->chip);
        kfree(dev->chip);
 }