Messages in this thread Patch in this message | | | From | Cengiz Can <> | Subject | [PATCH v2] staging: atomisp: move null check to earlier point | Date | Fri, 31 Jul 2020 01:17:38 +0300 |
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`find_gmin_subdev` function 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. ie:
``` /* Acquired here --------v */ struct gmin_subdev *gs = find_gmin_subdev(subdev);
/* v------Dereferenced here */ if (gs->v2p8_gpio >= 0) { ... } ```
To avoid the issue, null check has been moved to an earlier point and return semantics has been changed to reflect this exception.
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.
Caught-by: Coverity Static Analyzer CID 1465536 Signed-off-by: Cengiz Can <cengiz@kernel.wtf> --- 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
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