[RESEND PATCH] ALSA: rawmidi: fix infoleak in snd_rawmidi_ioctl_status_compat64

Xiaolong Huang butterflyhuangxx at gmail.com
Wed Nov 23 06:09:11 CET 2022


The compat_status is declared off of the stack, so it needs to
be zeroed out before copied back to userspace to prevent any
unintentional data leakage.

Fixes: d9e5582c4bb2 ("ALSA: Avoid using timespec for struct snd_rawmidi_status")
Signed-off-by: Xiaolong Huang <butterflyhuangxx at gmail.com>

---

Reason for resend:
1. add Fixes line.
---
 sound/core/rawmidi_compat.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sound/core/rawmidi_compat.c b/sound/core/rawmidi_compat.c
index 68a93443583c..6afa68165b17 100644
--- a/sound/core/rawmidi_compat.c
+++ b/sound/core/rawmidi_compat.c
@@ -80,6 +80,7 @@ static int snd_rawmidi_ioctl_status_compat64(struct snd_rawmidi_file *rfile,
 	if (err < 0)
 		return err;
 
+	memset(&compat_status, 0, sizeof(compat_status));
 	compat_status = (struct compat_snd_rawmidi_status64) {
 		.stream = status.stream,
 		.tstamp_sec = status.tstamp_sec,

base-commit: eb7081409f94a9a8608593d0fb63a1aa3d6f95d8
-- 
2.25.1



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