From b51ec7fc9f877ef869c01d3ea6f18f6a64e831a7 Mon Sep 17 00:00:00 2001 From: Ryosuke Yasuoka 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 Reviewed-by: Jeremy Cline Reviewed-by: Krzysztof Kozlowski Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- 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: