diff mbox series

[v1,1/2] Bluetooth: hci_core: Fix not checking skb length on hci_acldata_packet

Message ID 20241008154005.595169-1-luiz.dentz@gmail.com
State Superseded
Headers show
Series [v1,1/2] Bluetooth: hci_core: Fix not checking skb length on hci_acldata_packet | expand

Commit Message

Luiz Augusto von Dentz Oct. 8, 2024, 3:40 p.m. UTC 
From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

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@syzkaller.appspotmail.com
Tested-by: syzbot+6ea290ba76d8c1eb1ac2@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=6ea290ba76d8c1eb1ac2
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
---
 net/bluetooth/hci_core.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index b2f8f9c5b610..d5f917076e0e 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -3765,18 +3765,22 @@  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++;
 
@@ -3797,6 +3801,7 @@  static void hci_acldata_packet(struct hci_dev *hdev, struct sk_buff *skb)
 			   handle);
 	}
 
+drop:
 	kfree_skb(skb);
 }