linux-kernel - Re: [syzbot] [PATCH net v5] nfc: nci: Fix uninit-value in nci_rx

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <0000000000006e9dff0618c77ee2@google.com>
Date: Sat, 18 May 2024 22:02:38 -0700
From: syzbot <syzbot+d7b4dc6cd50410152534@...kaller.appspotmail.com>
To: linux-kernel@...r.kernel.org
Subject: Re: [syzbot] [PATCH net v5] nfc: nci: Fix uninit-value in nci_rx_work

For archival purposes, forwarding an incoming command email to
linux-kernel@...r.kernel.org.

***

Subject: [PATCH net v5] nfc: nci: Fix uninit-value in nci_rx_work
Author: ryasuoka@...hat.com

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git master

diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index b133dc55304c..7a9897fbf4f4 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -1463,6 +1463,19 @@ int nci_core_ntf_packet(struct nci_dev *ndev, __u16 opcode,
 				 ndev->ops->n_core_ops);
 }
 
+static bool nci_valid_size(struct sk_buff *skb)
+{
+	BUILD_BUG_ON(NCI_CTRL_HDR_SIZE != NCI_DATA_HDR_SIZE);
+	unsigned int hdr_size = NCI_CTRL_HDR_SIZE;
+
+	if (skb->len < hdr_size ||
+	    !nci_plen(skb->data) ||
+	    skb->len < hdr_size + nci_plen(skb->data)) {
+		return false;
+	}
+	return true;
+}
+
 /* ---- NCI TX Data worker thread ---- */
 
 static void nci_tx_work(struct work_struct *work)
@@ -1516,7 +1529,7 @@ static void nci_rx_work(struct work_struct *work)
 		nfc_send_to_raw_sock(ndev->nfc_dev, skb,
 				     RAW_PAYLOAD_NCI, NFC_DIRECTION_RX);
 
-		if (!nci_plen(skb->data)) {
+		if (!nci_valid_size(skb)) {
 			kfree_skb(skb);
 			kcov_remote_stop();
 			break;