From 856260a57cdfa5c121c7b7a6e816409bab07885c Mon Sep 17 00:00:00 2001 From: Devin Heitmueller Date: Mon, 22 Sep 2014 21:30:46 -0300 Subject: [media] xc5000: fix memory corruption when unplugging device This patch addresses a regression introduced in the following patch: commit 5264a522a597032c009f9143686ebf0fa4e244fb Author: Shuah Khan [media] media: tuner xc5000 - release firmwware from xc5000_release() The "priv" struct is actually reference counted, so the xc5000_release() function gets called multiple times for hybrid devices. Because release_firmware() was always being called, it would work fine as expected on the first call but then the second call would corrupt aribtrary memory. Set the pointer to NULL after releasing so that we don't call release_firmware() twice. This problem was detected in the HVR-950q where plugging/unplugging the device multiple times would intermittently show panics in completely unrelated areas of the kernel. Signed-off-by: Devin Heitmueller Cc: Shuah Khan Signed-off-by: Mauro Carvalho Chehab --- drivers/media/tuners/xc5000.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'drivers/media/tuners/xc5000.c') diff --git a/drivers/media/tuners/xc5000.c b/drivers/media/tuners/xc5000.c index 2a039de8ab9a..e6e5e90d8d95 100644 --- a/drivers/media/tuners/xc5000.c +++ b/drivers/media/tuners/xc5000.c @@ -1336,7 +1336,10 @@ static int xc5000_release(struct dvb_frontend *fe) if (priv) { cancel_delayed_work(&priv->timer_sleep); - release_firmware(priv->firmware); + if (priv->firmware) { + release_firmware(priv->firmware); + priv->firmware = NULL; + } hybrid_tuner_release_state(priv); } -- cgit