Original patch by Dan Rosenberg drosenberg@vsecurity.com under commit e68d3b316ab7b02a074edc4f770e6a746390cb7d. I'm copying his text here:
The SNDRV_HDSPM_IOCTL_GET_CONFIG_INFO ioctl in hdspm.c allow unprivileged users to read uninitialized kernel stack memory, because several fields of the hdspm_config struct declared on the stack are not altered or zeroed before being copied back to the user. This patch takes care of it.
Signed-off-by: Adrian Knoth adi@drcomp.erfurt.thur.de
diff --git a/sound/pci/rme9652/hdspm.c b/sound/pci/rme9652/hdspm.c index 0b0293f..ced1406 100644 --- a/sound/pci/rme9652/hdspm.c +++ b/sound/pci/rme9652/hdspm.c @@ -6081,6 +6081,7 @@ static int snd_hdspm_hwdep_ioctl(struct snd_hwdep *hw, struct file *file,
case SNDRV_HDSPM_IOCTL_GET_CONFIG:
+ memset(&info, 0, sizeof(info)); spin_lock_irq(&hdspm->lock); info.pref_sync_ref = hdspm_pref_sync_ref(hdspm); info.wordclock_sync_check = hdspm_wc_sync_check(hdspm);