On 04/03/2020 10:40, Tomi Valkeinen wrote:
On 03/03/2020 19:26, Benoit Parrot wrote:
After the switch to use v4l2_async_notifier_add_subdev() and v4l2_async_notifier_cleanup(), unloading the ti_cal module would casue a kernel oops.
This was root cause to the fact that v4l2_async_notifier_cleanup() tries to kfree the asd pointer passed into v4l2_async_notifier_add_subdev().
In our case the asd reference was from a statically allocated struct. So in effect v4l2_async_notifier_cleanup() was trying to free a pointer that was not kalloc.
So here we switch to using a kzalloc struct instead of a static one.
Fixes: d079f94c9046 ("media: platform: Switch to v4l2_async_notifier_add_subdev")
Cc: stable@vger.kernel.org Signed-off-by: Benoit Parrot bparrot@ti.com
drivers/media/platform/ti-vpe/cal.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/media/platform/ti-vpe/cal.c b/drivers/media/platform/ti-vpe/cal.c index 6d4cbb8782ed..18fe2cb9dd17 100644 --- a/drivers/media/platform/ti-vpe/cal.c +++ b/drivers/media/platform/ti-vpe/cal.c @@ -372,8 +372,6 @@ struct cal_ctx { struct v4l2_subdev *sensor; struct v4l2_fwnode_endpoint endpoint; - struct v4l2_async_subdev asd;
struct v4l2_fh fh; struct cal_dev *dev; struct cc_data *cc; @@ -2032,7 +2030,6 @@ static int of_cal_create_instance(struct cal_ctx *ctx, int inst) parent = pdev->dev.of_node; - asd = &ctx->asd; endpoint = &ctx->endpoint; ep_node = NULL; @@ -2040,6 +2037,10 @@ static int of_cal_create_instance(struct cal_ctx *ctx, int inst) sensor_node = NULL; ret = -EINVAL; + asd = kzalloc(sizeof(*asd), GFP_KERNEL); + if (!asd) + goto cleanup_exit;
ctx_dbg(3, ctx, "Scanning Port node for csi2 port: %d\n", inst); for (index = 0; index < CAL_NUM_CSI2_PORTS; index++) { port = of_get_next_port(parent, port);
Thanks, this fixes the crash for me.
It does look a bit odd that something is allocated with kzalloc, and then it's freed somewhere inside v4l2_async_notifier_cleanup, though. But if that's how it supposed to be used, looks fine to me.
Well, sent that a few seconds too early... With this patch, I see kmemleaks.
Tomi