| Message ID | 20200306130839.1209-1-bparrot@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] media: ti-vpe: cal: fix a kernel oops when unloading module | expand |
On 06/03/2020 15:08, 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. > To acheive this we re-order some of the calls to prevent asd allocation > from leaking. > > Fixes: d079f94c9046 ("media: platform: Switch to v4l2_async_notifier_add_subdev") > > Cc: stable@vger.kernel.org > Signed-off-by: Benoit Parrot <bparrot@ti.com> > --- > Changes since v1: > - fix asd allocation leak > > drivers/media/platform/ti-vpe/cal.c | 13 ++++++++----- > 1 file changed, 8 insertions(+), 5 deletions(-) Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Tomi
diff --git a/drivers/media/platform/ti-vpe/cal.c b/drivers/media/platform/ti-vpe/cal.c index 6d4cbb8782ed..6c8f3702eac0 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; @@ -2079,8 +2076,6 @@ static int of_cal_create_instance(struct cal_ctx *ctx, int inst) ctx_dbg(3, ctx, "can't get remote parent\n"); goto cleanup_exit; } - asd->match_type = V4L2_ASYNC_MATCH_FWNODE; - asd->match.fwnode = of_fwnode_handle(sensor_node); v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep_node), endpoint); @@ -2110,9 +2105,17 @@ static int of_cal_create_instance(struct cal_ctx *ctx, int inst) v4l2_async_notifier_init(&ctx->notifier); + asd = kzalloc(sizeof(*asd), GFP_KERNEL); + if (!asd) + goto cleanup_exit; + + asd->match_type = V4L2_ASYNC_MATCH_FWNODE; + asd->match.fwnode = of_fwnode_handle(sensor_node); + ret = v4l2_async_notifier_add_subdev(&ctx->notifier, asd); if (ret) { ctx_err(ctx, "Error adding asd\n"); + kfree(asd); goto cleanup_exit; }
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. To acheive this we re-order some of the calls to prevent asd allocation from leaking. Fixes: d079f94c9046 ("media: platform: Switch to v4l2_async_notifier_add_subdev") Cc: stable@vger.kernel.org Signed-off-by: Benoit Parrot <bparrot@ti.com> --- Changes since v1: - fix asd allocation leak drivers/media/platform/ti-vpe/cal.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-)