From: Anirudh Rayabharam <mail@anirudhrb.com>
To: "Michael S. Tsirkin" <mst@redhat.com>, Jason Wang <jasowang@redhat.com>
Cc: mail@anirudhrb.com,
syzbot+0abd373e2e50d704db87@syzkaller.appspotmail.com,
kvm@vger.kernel.org, virtualization@lists.linux-foundation.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] vhost: handle zero regions in vhost_set_memory
Date: Mon, 21 Feb 2022 12:58:51 +0530 [thread overview]
Message-ID: <20220221072852.31820-1-mail@anirudhrb.com> (raw)
Return early when userspace sends zero regions in the VHOST_SET_MEM_TABLE
ioctl.
Otherwise, this causes an erroneous entry to be added to the iotlb. This
entry has a range size of 0 (due to u64 overflow). This then causes
iotlb_access_ok() to loop indefinitely resulting in a hung thread.
Syzbot has reported this here:
https://syzkaller.appspot.com/bug?extid=0abd373e2e50d704db87
Reported-and-tested-by: syzbot+0abd373e2e50d704db87@syzkaller.appspotmail.com
Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com>
---
drivers/vhost/vhost.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 59edb5a1ffe2..821aba60eac2 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -1428,6 +1428,8 @@ static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m)
return -EFAULT;
if (mem.padding)
return -EOPNOTSUPP;
+ if (mem.nregions == 0)
+ return 0;
if (mem.nregions > max_mem_regions)
return -E2BIG;
newmem = kvzalloc(struct_size(newmem, regions, mem.nregions),
--
2.35.1
next reply other threads:[~2022-02-21 7:45 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-21 7:28 Anirudh Rayabharam [this message]
2022-02-21 7:56 ` [PATCH] vhost: handle zero regions in vhost_set_memory Jason Wang
2022-02-21 8:11 ` Anirudh Rayabharam
2022-02-21 16:48 ` Stefano Garzarella
2022-02-21 17:59 ` Anirudh Rayabharam
2022-02-21 19:57 ` Anirudh Rayabharam
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