[PATCH AUTOSEL 6.1 44/48] Bluetooth: hci_core: Fix not checking skb length on hci_acldata_packet
From: Sasha Levin
Date: Sun Nov 24 2024 - 12:35:06 EST
From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
[ Upstream commit 3fe288a8214e7dd784d1f9b7c9e448244d316b47 ]
This fixes not checking if skb really contains an ACL header otherwise
the code may attempt to access some uninitilized/invalid memory past the
valid skb->data.
Reported-by: syzbot+6ea290ba76d8c1eb1ac2@xxxxxxxxxxxxxxxxxxxxxxxxx
Tested-by: syzbot+6ea290ba76d8c1eb1ac2@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=6ea290ba76d8c1eb1ac2
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/bluetooth/hci_core.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 789f7f4a09089..3cd7c212375fc 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -3829,18 +3829,22 @@ static void hci_tx_work(struct work_struct *work)
/* ACL data packet */
static void hci_acldata_packet(struct hci_dev *hdev, struct sk_buff *skb)
{
- struct hci_acl_hdr *hdr = (void *) skb->data;
+ struct hci_acl_hdr *hdr;
struct hci_conn *conn;
__u16 handle, flags;
- skb_pull(skb, HCI_ACL_HDR_SIZE);
+ hdr = skb_pull_data(skb, sizeof(*hdr));
+ if (!hdr) {
+ bt_dev_err(hdev, "ACL packet too small");
+ goto drop;
+ }
handle = __le16_to_cpu(hdr->handle);
flags = hci_flags(handle);
handle = hci_handle(handle);
- BT_DBG("%s len %d handle 0x%4.4x flags 0x%4.4x", hdev->name, skb->len,
- handle, flags);
+ bt_dev_dbg(hdev, "len %d handle 0x%4.4x flags 0x%4.4x", skb->len,
+ handle, flags);
hdev->stat.acl_rx++;
@@ -3859,6 +3863,7 @@ static void hci_acldata_packet(struct hci_dev *hdev, struct sk_buff *skb)
handle);
}
+drop:
kfree_skb(skb);
}
--
2.43.0