diff options
| author | Ashutosh Desai <ashutoshdesai993@gmail.com> | 2026-05-05 17:07:12 +0000 |
|---|---|---|
| committer | David Heidelberg <david@ixit.cz> | 2026-05-07 12:42:09 +0200 |
| commit | f040e590c035bfd9553fe79ee9585caf1b14d67b (patch) | |
| tree | a5c6d535270073d0691fbce9a3f502f55781504a | |
| parent | b493ea2765cc17cb8aa7e7544a4b6dcb05b6ed77 (diff) | |
nfc: hci: fix out-of-bounds read in HCP header parsing
Both nfc_hci_recv_from_llc() and nci_hci_data_received_cb() read
packet->header from skb->data at function entry without first checking
that the buffer holds at least one byte. A malicious NFC peer can send
a 0-byte HCP frame that passes through the SHDLC layer and reaches
these functions, causing an out-of-bounds heap read of packet->header.
The same 0-byte frame, if queued as a non-final fragment, also causes
the reassembly loop to underflow msg_len to UINT_MAX, triggering
skb_over_panic() when the reassembled skb is written.
Fix this by adding a pskb_may_pull() check at the entry of each
function before packet->header is first accessed. The existing
pskb_may_pull() checks before the reassembled hcp_skb is cast to
struct hcp_packet remain in place to guard the 2-byte HCP message
header.
Fixes: 8b8d2e08bf0d ("NFC: HCI support")
Fixes: 11f54f228643 ("NFC: nci: Add HCI over NCI protocol support")
Cc: stable@vger.kernel.org
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Ashutosh Desai <ashutoshdesai993@gmail.com>
Link: https://patch.msgid.link/20260505170712.96560-1-ashutoshdesai993@gmail.com
Signed-off-by: David Heidelberg <david@ixit.cz>
| -rw-r--r-- | net/nfc/hci/core.c | 10 | ||||
| -rw-r--r-- | net/nfc/nci/hci.c | 10 |
2 files changed, 20 insertions, 0 deletions
diff --git a/net/nfc/hci/core.c b/net/nfc/hci/core.c index 0d33c81a15fe..ba6f0310ffd7 100644 --- a/net/nfc/hci/core.c +++ b/net/nfc/hci/core.c @@ -861,6 +861,11 @@ static void nfc_hci_recv_from_llc(struct nfc_hci_dev *hdev, struct sk_buff *skb) struct sk_buff *frag_skb; int msg_len; + if (!pskb_may_pull(skb, NFC_HCI_HCP_PACKET_HEADER_LEN)) { + kfree_skb(skb); + return; + } + packet = (struct hcp_packet *)skb->data; if ((packet->header & ~NFC_HCI_FRAGMENT) == 0) { skb_queue_tail(&hdev->rx_hcp_frags, skb); @@ -904,6 +909,11 @@ static void nfc_hci_recv_from_llc(struct nfc_hci_dev *hdev, struct sk_buff *skb) * unblock waiting cmd context. Otherwise, enqueue to dispatch * in separate context where handler can also execute command. */ + if (!pskb_may_pull(hcp_skb, NFC_HCI_HCP_HEADER_LEN)) { + kfree_skb(hcp_skb); + return; + } + packet = (struct hcp_packet *)hcp_skb->data; type = HCP_MSG_GET_TYPE(packet->message.header); if (type == NFC_HCI_HCP_RESPONSE) { diff --git a/net/nfc/nci/hci.c b/net/nfc/nci/hci.c index 40ae8e5a7ec7..c03e8a0bd3bd 100644 --- a/net/nfc/nci/hci.c +++ b/net/nfc/nci/hci.c @@ -439,6 +439,11 @@ void nci_hci_data_received_cb(void *context, return; } + if (!pskb_may_pull(skb, NCI_HCI_HCP_PACKET_HEADER_LEN)) { + kfree_skb(skb); + return; + } + packet = (struct nci_hcp_packet *)skb->data; if ((packet->header & ~NCI_HCI_FRAGMENT) == 0) { skb_queue_tail(&ndev->hci_dev->rx_hcp_frags, skb); @@ -482,6 +487,11 @@ void nci_hci_data_received_cb(void *context, * unblock waiting cmd context. Otherwise, enqueue to dispatch * in separate context where handler can also execute command. */ + if (!pskb_may_pull(hcp_skb, NCI_HCI_HCP_HEADER_LEN)) { + kfree_skb(hcp_skb); + return; + } + packet = (struct nci_hcp_packet *)hcp_skb->data; type = NCI_HCP_MSG_GET_TYPE(packet->message.header); if (type == NCI_HCI_HCP_RESPONSE) { |