lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Date:   Sun,  2 Aug 2020 01:01:02 +0300
From:   Cengiz Can <cengiz@...nel.wtf>
To:     andy.shevchenko@...il.com
Cc:     cengiz@...nel.wtf, dan.carpenter@...cle.com,
        devel@...verdev.osuosl.org, gregkh@...uxfoundation.org,
        linux-kernel@...r.kernel.org, linux-media@...r.kernel.org,
        mchehab@...nel.org, sakari.ailus@...ux.intel.com
Subject: [PATCH v6] staging: atomisp: move null check to earlier point

`find_gmin_subdev()` that returns a pointer to `struct
gmin_subdev` can return NULL.

In `gmin_v2p8_ctrl()` there's a call to this function but the
possibility of a NULL was not checked before its being dereferenced,
i.e.:

  /* Acquired here --------v */
  struct gmin_subdev *gs = find_gmin_subdev(subdev);

  /*  v------Dereferenced here */
  if (gs->v2p8_gpio >= 0) {
      ...
  }

With this change we're null checking `find_gmin_subdev()` result
and we return an error if that's the case. We also WARN()
for the sake of debugging.

Signed-off-by: Cengiz Can <cengiz@...nel.wtf>
Reported-by: Coverity Static Analyzer CID 1465536
Suggested-by: Mauro Carvalho Chehab <mchehab@...nel.org>
---

 Please do note that this change introduces a new return value to
 `gmin_v2p8_ctrl()`.

 [NEW] - raise a WARN and return -ENODEV if there are no subdevices.
       - return result of `gpio_request` or `gpio_direction_output`.
       - return 0 if GPIO is ON.
       - return results of `regulator_enable` or `regulator_disable`.
       - according to PMIC type, return result of `axp_regulator_set`
         or `gmin_i2c_write`.
       - return -EINVAL if unknown PMIC type.

 Patch Changelog:
   v4: Fix minor typo in commit message
   v5: Remove typo from email subject
   v6: Remove duplicate Signed-off-by tag

 drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c b/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
index 0df46a1af5f0..1ad0246764a6 100644
--- a/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
+++ b/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
@@ -871,6 +871,9 @@ static int gmin_v2p8_ctrl(struct v4l2_subdev *subdev, int on)
 	int ret;
 	int value;
 
+	if (WARN_ON(!gs))
+		return -ENODEV;
+
 	if (gs->v2p8_gpio >= 0) {
 		pr_info("atomisp_gmin_platform: 2.8v power on GPIO %d\n",
 			gs->v2p8_gpio);
@@ -881,7 +884,7 @@ static int gmin_v2p8_ctrl(struct v4l2_subdev *subdev, int on)
 			pr_err("V2P8 GPIO initialization failed\n");
 	}
 
-	if (!gs || gs->v2p8_on == on)
+	if (gs->v2p8_on == on)
 		return 0;
 	gs->v2p8_on = on;
 
-- 
2.27.0

Powered by blists - more mailing lists