When driver is built as module and probe during insmod is deferred because of sensor subdevs, there is NULL pointer deference because mdev is cleaned up and then access it from v4l2_device_unregister(). Fix the wrong mdev and v4l2 dev odder in error path of probe. This fixes below null pointer deference: Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = ca026f68 [00000000] *pgd=00000000 Internal error: Oops: 5 [#1] PREEMPT SMP ARM [...] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) PC is at ida_free+0x7c/0x160 LR is at xas_start+0x44/0x204 [...] [<c0dafd60>] (ida_free) from [<c083c20c>] (__media_device_unregister_entity+0x18/0xc0) [<c083c20c>] (__media_device_unregister_entity) from [<c083c2e0>] (media_device_unregister_entity+0x2c/0x38) [<c083c2e0>] (media_device_unregister_entity) from [<c0843404>] (v4l2_device_release+0xd0/0x104) [<c0843404>] (v4l2_device_release) from [<c0632558>] (device_release+0x28/0x98) [<c0632558>] (device_release) from [<c0db1204>] (kobject_put+0xa4/0x208) [<c0db1204>] (kct_put) from [<bf00bac4>] (fimc_capture_subdev_unregistered+0x58/0x6c [s5p_fimc]) [<bf00bac4>] (fimc_capture_subdev_unregistered [s5p_fimc]) from [<c084a1cc>] (v4l2_device_unregister_subdev+0x6c/0xa8) [<c084a1cc>] (v4l2_device_unregister_subdev) from [<c084a350>] (v4l2_device_unregister+0x64/0x94) [<c084a350>] (v4l2_device_unregister) from [<bf0101ac>] (fimc_md_probe+0x4ec/0xaf8 [s5p_fimc]) [...] Signed-off-by: Seung-Woo Kim <sw0312.kim@xxxxxxxxxxx> --- drivers/media/platform/exynos4-is/media-dev.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/drivers/media/platform/exynos4-is/media-dev.c b/drivers/media/platform/exynos4-is/media-dev.c index a838189..3685c91e6 100644 --- a/drivers/media/platform/exynos4-is/media-dev.c +++ b/drivers/media/platform/exynos4-is/media-dev.c @@ -1520,8 +1520,8 @@ static int fimc_md_probe(struct platform_device *pdev) err_clk: fimc_md_put_clocks(fmd); err_md: - media_device_cleanup(&fmd->media_dev); v4l2_device_unregister(&fmd->v4l2_dev); + media_device_cleanup(&fmd->media_dev); return ret; } -- 1.7.4.1
