From: Brad Love <brad@nextdimension.cc>
Date: Fri, 5 Jan 2018 14:57:13 +0000 (-0500)
Subject: media: lgdt3306a: Fix a double kfree on i2c device remove
X-Git-Tag: v4.19~1321^2~267
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=94448e21cf08b10f7dc7acdaca387594370396b0;p=platform%2Fkernel%2Flinux-rpi.git

media: lgdt3306a: Fix a double kfree on i2c device remove

Both lgdt33606a_release and lgdt3306a_remove kfree state, but _release is
called first, then _remove operates on states members before kfree'ing it.
This can lead to random oops/GPF/etc on USB disconnect.

Signed-off-by: Brad Love <brad@nextdimension.cc>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
---

diff --git a/drivers/media/dvb-frontends/lgdt3306a.c b/drivers/media/dvb-frontends/lgdt3306a.c
index adcaf9b..0ed6460 100644
--- a/drivers/media/dvb-frontends/lgdt3306a.c
+++ b/drivers/media/dvb-frontends/lgdt3306a.c
@@ -1814,7 +1814,13 @@ static void lgdt3306a_release(struct dvb_frontend *fe)
 	struct lgdt3306a_state *state = fe->demodulator_priv;
 
 	dbg_info("\n");
-	kfree(state);
+
+	/*
+	 * If state->muxc is not NULL, then we are an i2c device
+	 * and lgdt3306a_remove will clean up state
+	 */
+	if (!state->muxc)
+		kfree(state);
 }
 
 static const struct dvb_frontend_ops lgdt3306a_ops;