In snd_timer_proc_read(), there is an if statement on line 1204 to check
whether timer->card is NULL:
if (timer->card && timer->card->shutdown)
When timer->card is NULL, it is used on lines 1212 and 1215:
timer->card->number
Thus, possible null-pointer dereferences may occur.
To fix these bugs, timer->card is checked before being used.
These bugs are found by a static analysis tool STCheck written by us.
Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
---
sound/core/timer.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/sound/core/timer.c b/sound/core/timer.c
index 5c9fbf3f4340..967d06a3cdec 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -1208,11 +1208,13 @@ static void snd_timer_proc_read(struct snd_info_entry *entry,
snd_iprintf(buffer, "G%i: ", timer->tmr_device);
break;
case SNDRV_TIMER_CLASS_CARD:
- snd_iprintf(buffer, "C%i-%i: ",
- timer->card->number, timer->tmr_device);
+ snd_iprintf(buffer, "C%i-%i: ",
+ timer->card ? timer->card->number : -1,
+ timer->tmr_device);
break;
case SNDRV_TIMER_CLASS_PCM:
- snd_iprintf(buffer, "P%i-%i-%i: ", timer->card->number,
+ snd_iprintf(buffer, "P%i-%i-%i: ",
+ timer->card ? timer->card->number : -1,
timer->tmr_device, timer->tmr_subdevice);
break;
default:
--
2.17.0
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