Coverity spotted the following possible use-after-free condition in dapm_create_or_share_mixmux_kcontrol():
If kcontrol is NULL, and (wname_in_long_name && kcname_in_long_name) validates to true, 'name' will be set to an allocated string, and be freed a few lines later via the 'long_name' alias. 'name', however, is used by dev_err() in case snd_ctl_add() fails.
Fix this by adding a jump label that frees 'long_name' at the end of the function.
Signed-off-by: Daniel Mack daniel@zonque.org --- sound/soc/soc-dapm.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-)
diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c index 2c456a3..c61cb9c 100644 --- a/sound/soc/soc-dapm.c +++ b/sound/soc/soc-dapm.c @@ -592,9 +592,9 @@ static int dapm_create_or_share_mixmux_kcontrol(struct snd_soc_dapm_widget *w, int shared; struct snd_kcontrol *kcontrol; bool wname_in_long_name, kcname_in_long_name; - char *long_name; + char *long_name = NULL; const char *name; - int ret; + int ret = 0;
prefix = soc_dapm_prefix(dapm); if (prefix) @@ -653,15 +653,17 @@ static int dapm_create_or_share_mixmux_kcontrol(struct snd_soc_dapm_widget *w,
kcontrol = snd_soc_cnew(&w->kcontrol_news[kci], NULL, name, prefix); - kfree(long_name); - if (!kcontrol) - return -ENOMEM; + if (!kcontrol) { + ret = -ENOMEM; + goto exit_free; + } + kcontrol->private_free = dapm_kcontrol_free;
ret = dapm_kcontrol_data_alloc(w, kcontrol); if (ret) { snd_ctl_free_one(kcontrol); - return ret; + goto exit_free; }
ret = snd_ctl_add(card, kcontrol); @@ -669,17 +671,18 @@ static int dapm_create_or_share_mixmux_kcontrol(struct snd_soc_dapm_widget *w, dev_err(dapm->dev, "ASoC: failed to add widget %s dapm kcontrol %s: %d\n", w->name, name, ret); - return ret; + goto exit_free; } }
ret = dapm_kcontrol_add_widget(kcontrol, w); - if (ret) - return ret; + if (ret == 0) + w->kcontrols[kci] = kcontrol;
- w->kcontrols[kci] = kcontrol; +exit_free: + kfree(long_name);
- return 0; + return ret; }
/* create new dapm mixer control */