Guys: I'm getting the following OOPS: [ 2.952388] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [ 2.952388] pgd = dfca4000 [ 2.952418] [00000000] *pgd=a70cb831, *pte=00000000, *ppte=00000000 [ 2.952418] Internal error: Oops: 17 [#1] PREEMPT SMP [ 2.952418] Modules linked in: [ 2.952418] CPU: 0 Not tainted (3.0.21-perf+ #1) [ 2.952449] PC is at msm_vfe_subdev_ioctl+0x14/0x4614 [ 2.952449] LR is at subdev_do_ioctl+0x43c/0x49c Referring to commit d358ecdb, I see a lot of code that looks like this in msm_vfe_subdev_ioctl(): static long msm_vfe_subdev_ioctl(struct v4l2_subdev *sd, unsigned int subdev_cmd, void *arg) { ... struct msm_camvfe_params *vfe_params = (struct msm_camvfe_params *)arg; struct msm_vfe_cfg_cmd *cmd = vfe_params->vfe_cfg; void *data = vfe_params->data; ... struct axidata *axid; axid = data; ... regptr = axid->region; if (axid->bufnum1 > 0) { ... } In other words, you're dereferencing the parameters passed to the ioctl directly, rather than through copy_from_user(). I can't say for sure that this is the root cause of my OOPSing, but it is very, very suspicious code. Or am I just misunderstanding something? I chose this particular commit because it's the BSP v1.2 release from Intrinsyc for the Dragonboard APQ8060A, which is my target device at present. I haven't yet looked to see if this code is changed in later commits... b.g. -- Bill Gatliff bgat@xxxxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html