From c97d96b4e612c7dc1b37d7afc61b598a9a25994d Mon Sep 17 00:00:00 2001 From: Phil Elwell Date: Sun, 24 Sep 2017 15:20:49 +0100 Subject: staging: bcm2835-audio: Fix memory corruption The previous commit (0adbfd46) fixed a memory leak but also freed a block in the success case, causing a stale pointer to be used with potentially fatal results. Only free the vchi_instance block in the case that vchi_connect fails; once connected, the instance is retained for subsequent connections. Simplifying the code by removing a bunch of gotos and returning errors directly. Signed-off-by: Phil Elwell Fixes: 0adbfd4694c2 ("staging: bcm2835-audio: fix memory leak in bcm2835_audio_open_connection()") Cc: stable # 4.12+ Tested-by: Stefan Wahren Signed-off-by: Greg Kroah-Hartman --- .../vc04_services/bcm2835-audio/bcm2835-vchiq.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-) diff --git a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c index 5f3d8f2339e3..4be864dbd41c 100644 --- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c +++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-vchiq.c @@ -390,8 +390,7 @@ static int bcm2835_audio_open_connection(struct bcm2835_alsa_stream *alsa_stream __func__, instance); instance->alsa_stream = alsa_stream; alsa_stream->instance = instance; - ret = 0; // xxx todo -1; - goto err_free_mem; + return 0; } /* Initialize and create a VCHI connection */ @@ -401,16 +400,15 @@ static int bcm2835_audio_open_connection(struct bcm2835_alsa_stream *alsa_stream LOG_ERR("%s: failed to initialise VCHI instance (ret=%d)\n", __func__, ret); - ret = -EIO; - goto err_free_mem; + return -EIO; } ret = vchi_connect(NULL, 0, vchi_instance); if (ret) { LOG_ERR("%s: failed to connect VCHI instance (ret=%d)\n", __func__, ret); - ret = -EIO; - goto err_free_mem; + kfree(vchi_instance); + return -EIO; } initted = 1; } @@ -421,19 +419,16 @@ static int bcm2835_audio_open_connection(struct bcm2835_alsa_stream *alsa_stream if (IS_ERR(instance)) { LOG_ERR("%s: failed to initialize audio service\n", __func__); - ret = PTR_ERR(instance); - goto err_free_mem; + /* vchi_instance is retained for use the next time. */ + return PTR_ERR(instance); } instance->alsa_stream = alsa_stream; alsa_stream->instance = instance; LOG_DBG(" success !\n"); - ret = 0; -err_free_mem: - kfree(vchi_instance); - return ret; + return 0; } int bcm2835_audio_open(struct bcm2835_alsa_stream *alsa_stream) -- cgit v1.2.3