From b51ec7fc9f877ef869c01d3ea6f18f6a64e831a7 Mon Sep 17 00:00:00 2001
From: Ryosuke Yasuoka <ryasuoka@redhat.com>
Date: Wed, 20 Mar 2024 09:54:10 +0900
Subject: [PATCH] nfc: nci: Fix uninit-value in nci_dev_up and nci_ntf_packet
[ Upstream commit d24b03535e5eb82e025219c2f632b485409c898f ]
syzbot reported the following uninit-value access issue [1][2]:
nci_rx_work() parses and processes received packet. When the payload
length is zero, each message type handler reads uninitialized payload
and KMSAN detects this issue. The receipt of a packet with a zero-size
payload is considered unexpected, and therefore, such packets should be
silently discarded.
This patch resolved this issue by checking payload size before calling
each message type handler codes.
Fixes: 6a2968aaf50c ("NFC: basic NCI protocol implementation")
Reported-and-tested-by: syzbot+7ea9413ea6749baf5574@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+29b5ca705d2e0f4a44d2@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=7ea9413ea6749baf5574 [1]
Closes: https://syzkaller.appspot.com/bug?extid=29b5ca705d2e0f4a44d2 [2]
Signed-off-by: Ryosuke Yasuoka <ryasuoka@redhat.com>
Reviewed-by: Jeremy Cline <jeremy@jcline.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/nfc/nci/core.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index b5071a2f597d..f76a2d806034 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -1512,6 +1512,11 @@ 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)) {
+ kfree_skb(skb);
+ break;
+ }
+
/* Process frame */
switch (nci_mt(skb->data)) {
case NCI_MT_RSP_PKT: