From c37a6b80c3679de42f047764822b97d784b1d364 Mon Sep 17 00:00:00 2001 From: Pavel Skripkin Date: Wed, 27 Apr 2022 11:10:17 +0800 Subject: [PATCH] Bluetooth: stop proccessing malicious adv data stable inclusion from stable-v5.10.94 commit ffc9019bd991707701273c2e5d8aed472229fc4d bugzilla: https://gitee.com/openeuler/kernel/issues/I531X9 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ffc9019bd991707701273c2e5d8aed472229fc4d -------------------------------- [ Upstream commit 3a56ef719f0b9682afb8a86d64b2399e36faa4e6 ] Syzbot reported slab-out-of-bounds read in hci_le_adv_report_evt(). The problem was in missing validaion check. We should check if data is not malicious and we can read next data block. If we won't check ptr validness, code can read a way beyond skb->end and it can cause problems, of course. Fixes: e95beb414168 ("Bluetooth: hci_le_adv_report_evt code refactoring") Reported-and-tested-by: syzbot+e3fcb9c4f3c2a931dc40@syzkaller.appspotmail.com Signed-off-by: Pavel Skripkin Signed-off-by: Marcel Holtmann Signed-off-by: Sasha Levin Signed-off-by: Zheng Zengkai Acked-by: Xie XiuQi --- net/bluetooth/hci_event.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index 9f52145bb7b7..7ffcca9ae82a 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -5661,7 +5661,8 @@ static void hci_le_adv_report_evt(struct hci_dev *hdev, struct sk_buff *skb) struct hci_ev_le_advertising_info *ev = ptr; s8 rssi; - if (ev->length <= HCI_MAX_AD_LENGTH) { + if (ev->length <= HCI_MAX_AD_LENGTH && + ev->data + ev->length <= skb_tail_pointer(skb)) { rssi = ev->data[ev->length]; process_adv_report(hdev, ev->evt_type, &ev->bdaddr, ev->bdaddr_type, NULL, 0, rssi, @@ -5671,6 +5672,11 @@ static void hci_le_adv_report_evt(struct hci_dev *hdev, struct sk_buff *skb) } ptr += sizeof(*ev) + ev->length + 1; + + if (ptr > (void *) skb_tail_pointer(skb) - sizeof(*ev)) { + bt_dev_err(hdev, "Malicious advertising data. Stopping processing"); + break; + } } hci_dev_unlock(hdev); -- GitLab