[PATCH 5.6 088/254] media: ti-vpe: cal: fix a kernel oops when unloading module
From: Greg Kroah-Hartman
Date: Thu Apr 16 2020 - 10:58:18 EST
From: Benoit Parrot <bparrot@xxxxxx>
commit 80264809ea0a3fd2ee8251f31a9eb85d2c3fc77e upstream.
After the switch to use v4l2_async_notifier_add_subdev() and
v4l2_async_notifier_cleanup(), unloading the ti_cal module would cause 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 achieve 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@xxxxxxxxxxxxxxx
Signed-off-by: Benoit Parrot <bparrot@xxxxxx>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@xxxxxx>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/media/platform/ti-vpe/cal.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
--- 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
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
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
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;
}