[PATCH 5.4 129/215] nfc: nci: Fix uninit-value in nci_dev_up and nci_ntf_packet

Greg Kroah-Hartman
2024-04-11T10:20:21Z

From: Ryosuke Yasuoka <ryasuoka@redhat.com>

[ 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 cb2193dec7129..701c3752bda09 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -1499,6 +1499,11 @@ 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:
--
2.43.0