[alsa-devel] [PATCH 3/3] alsa-lib: fixed coverity reported issues under "USE_AFTER_FREE" checker.

sudarshan.bisht at nokia.com sudarshan.bisht at nokia.com
Tue Apr 12 12:09:47 CEST 2011


From: Sudarshan Bisht <sudarshan.bisht at nokia.com>

Coverity Static Analysis helps developers find hard-to-spot,
yet potentially crash-causing defects early in the development phase,
reducing the cost,time, and risk of software errors.

This patch has a fix for conditions where 1) variable is used
evern after getting freed thus causing junk assignment and 2) double
free of memory.

---
 modules/mixer/simple/python.c |    1 +
 src/control/control_hw.c      |    1 +
 src/mixer/mixer.c             |    1 -
 3 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/modules/mixer/simple/python.c b/modules/mixer/simple/python.c
index c822c52..784d9a0 100644
--- a/modules/mixer/simple/python.c
+++ b/modules/mixer/simple/python.c
@@ -663,6 +663,7 @@ pymixer_attach_hctl(struct pymixer *pymixer, PyObject *args)
 		return NULL;
 	err = snd_mixer_attach_hctl(pymixer->mixer, hctl);
 	if (err < 0) {
+		snd_hctl_close(hctl);
 		PyErr_Format(PyExc_RuntimeError, "Cannot attach hctl: %s", snd_strerror(err));
 		return NULL;
 	}
diff --git a/src/control/control_hw.c b/src/control/control_hw.c
index cf258b4..16c4987 100644
--- a/src/control/control_hw.c
+++ b/src/control/control_hw.c
@@ -414,6 +414,7 @@ int snd_ctl_hw_open(snd_ctl_t **handle, const char *name, int card, int mode)
 	if (err < 0) {
 		close(fd);
 		free(hw);
+		return err;
 	}
 	ctl->ops = &snd_ctl_hw_ops;
 	ctl->private_data = hw;
diff --git a/src/mixer/mixer.c b/src/mixer/mixer.c
index 85d843f..5e5789a 100644
--- a/src/mixer/mixer.c
+++ b/src/mixer/mixer.c
@@ -228,7 +228,6 @@ int snd_mixer_attach_hctl(snd_mixer_t *mixer, snd_hctl_t *hctl)
 		return -ENOMEM;
 	err = snd_hctl_nonblock(hctl, 1);
 	if (err < 0) {
-		snd_hctl_close(hctl);
 		free(slave);
 		return err;
 	}
-- 
1.7.0.4



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