From f41a4b2b5eb7872109723dab8ae1603bdd9d9ec1 Mon Sep 17 00:00:00 2001 From: Pavel Skripkin Date: Thu, 19 Aug 2021 18:15:21 +0300 Subject: Bluetooth: add timeout sanity check to hci_inquiry Syzbot hit "task hung" bug in hci_req_sync(). The problem was in unreasonable huge inquiry timeout passed from userspace. Fix it by adding sanity check for timeout value to hci_inquiry(). Since hci_inquiry() is the only user of hci_req_sync() with user controlled timeout value, it makes sense to check timeout value in hci_inquiry() and don't touch hci_req_sync(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-and-tested-by: syzbot+be2baed593ea56c6a84c@syzkaller.appspotmail.com Signed-off-by: Pavel Skripkin Signed-off-by: Marcel Holtmann --- net/bluetooth/hci_core.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'net/bluetooth') diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index 8622da2d9395..f033c19e2f3b 100644 --- a/net/bluetooth/hci_core.c +++ b/net/bluetooth/hci_core.c @@ -1343,6 +1343,12 @@ int hci_inquiry(void __user *arg) goto done; } + /* Restrict maximum inquiry length to 60 seconds */ + if (ir.length > 60) { + err = -EINVAL; + goto done; + } + hci_dev_lock(hdev); if (inquiry_cache_age(hdev) > INQUIRY_CACHE_AGE_MAX || inquiry_cache_empty(hdev) || ir.flags & IREQ_CACHE_FLUSH) { -- cgit v1.2.3