On 5/3/21 5:06 PM, Shuah Khan wrote:
Hi Igor,
On 5/3/21 11:37 AM, Igor Matheus Andrade Torrente wrote:
The em28xx struct kref isn't being decreased after an error in the
em28xx_ir_init, leading to a possible memory leak.
A kref_put is added to the error handler code.
Signed-off-by: Igor Matheus Andrade Torrente <igormtorrente@xxxxxxxxx>
---
drivers/media/usb/em28xx/em28xx-input.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/media/usb/em28xx/em28xx-input.c
b/drivers/media/usb/em28xx/em28xx-input.c
index 5aa15a7a49de..b89527014cad 100644
--- a/drivers/media/usb/em28xx/em28xx-input.c
+++ b/drivers/media/usb/em28xx/em28xx-input.c
@@ -720,7 +720,8 @@ static int em28xx_ir_init(struct em28xx *dev)
dev->board.has_ir_i2c = 0;
dev_warn(&dev->intf->dev,
"No i2c IR remote control device found.\n");
- return -ENODEV;
+ err = -ENODEV;
+ goto ref_put;
This doesn't look right. em28xx_init_buttons() is already happened and
em28xx_shutdown_buttons() needs to be done from fini. fini needs to run
with this ref. If ref is released here, device might be released before
em28xx_shutdown_buttons() can run leading to potential use-after-free
Thanks for the feedback.
I sent a patch V2 that I think fix the problem pointed out.
}
}
@@ -735,7 +736,7 @@ static int em28xx_ir_init(struct em28xx *dev)
ir = kzalloc(sizeof(*ir), GFP_KERNEL);
if (!ir)
- return -ENOMEM;
+ goto ref_put;
This doesn't look right. Same comment as above. fini accounts for null
ir.
em28xx_shutdown_buttons(dev);
/* skip detach on non attached boards */
if (!ir)
goto ref_put;
rc = rc_allocate_device(RC_DRIVER_SCANCODE);
if (!rc)
goto error;
@@ -839,6 +840,8 @@ static int em28xx_ir_init(struct em28xx *dev)
dev->ir = NULL;
rc_free_device(rc);
kfree(ir);
+ref_put:
+ kref_put(&dev->ref, em28xx_free_device);
return err;
}
thanks,
-- Shuah
Best regard,
---
Igor M. A. Torrente
