From 024e01dead12c2b9fbe31216f2099401ebb78a4a Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Fri, 27 Nov 2020 10:36:32 +0100 Subject: media: pulse8-cec: fix duplicate free at disconnect or probe error Commit 601282d65b96 ("media: pulse8-cec: use adap_free callback") used the adap_free callback to clean up on disconnect. What I forgot was that in the probe it will call cec_delete_adapter() followed by kfree(pulse8) if an error occurs. But by using the adap_free callback, cec_delete_adapter() is already freeing the pulse8 struct. This wasn't noticed since normally the probe works fine, but Pulse-Eight published a new firmware version that caused a probe error, so now it hits this bug. This affects firmware version 12, but probably any version >= 10. Commit aa9eda76129c ("media: pulse8-cec: close serio in disconnect, not adap_free") made this worse by adding the line 'pulse8->serio = NULL' right after the call to cec_unregister_adapter in the disconnect() function. Unfortunately, cec_unregister_adapter will typically call cec_delete_adapter (unless a filehandle to the cec device is still open), which frees the pulse8 struct. So now it will also crash on a simple unplug of the Pulse-Eight device. With this fix both the unplug issue and a probe() error situation are handled correctly again. It will still fail to probe() with a v12 firmware, that's something to look at separately. Signed-off-by: Hans Verkuil Reported-by: Maxime Ripard Tested-by: Maxime Ripard Fixes: aa9eda76129c ("media: pulse8-cec: close serio in disconnect, not adap_free") Fixes: 601282d65b96 ("media: pulse8-cec: use adap_free callback") Cc: Signed-off-by: Mauro Carvalho Chehab --- drivers/media/cec/usb/pulse8/pulse8-cec.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'drivers/media/cec') diff --git a/drivers/media/cec/usb/pulse8/pulse8-cec.c b/drivers/media/cec/usb/pulse8/pulse8-cec.c index e4d8446b87da..5d3a3f775bc8 100644 --- a/drivers/media/cec/usb/pulse8/pulse8-cec.c +++ b/drivers/media/cec/usb/pulse8/pulse8-cec.c @@ -650,7 +650,6 @@ static void pulse8_disconnect(struct serio *serio) struct pulse8 *pulse8 = serio_get_drvdata(serio); cec_unregister_adapter(pulse8->adap); - pulse8->serio = NULL; serio_set_drvdata(serio, NULL); serio_close(serio); } @@ -830,8 +829,10 @@ static int pulse8_connect(struct serio *serio, struct serio_driver *drv) pulse8->adap = cec_allocate_adapter(&pulse8_cec_adap_ops, pulse8, dev_name(&serio->dev), caps, 1); err = PTR_ERR_OR_ZERO(pulse8->adap); - if (err < 0) - goto free_device; + if (err < 0) { + kfree(pulse8); + return err; + } pulse8->dev = &serio->dev; serio_set_drvdata(serio, pulse8); @@ -874,8 +875,6 @@ close_serio: serio_close(serio); delete_adap: cec_delete_adapter(pulse8->adap); -free_device: - kfree(pulse8); return err; } -- cgit v1.2.3-59-g8ed1b