This is a note to let you know that I've just added the patch titled nfc: nci: Fix uninit-value in nci_dev_up and nci_ntf_packet to the 6.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: nfc-nci-fix-uninit-value-in-nci_dev_up-and-nci_ntf_p.patch and it can be found in the queue-6.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 5dee6c3d953de0bf14841fdfc896f92eaab31548 Author: Ryosuke Yasuoka <ryasuoka@xxxxxxxxxx> Date: Wed Mar 20 09:54:10 2024 +0900 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@xxxxxxxxxxxxxxxxxxxxxxxxx Reported-and-tested-by: syzbot+29b5ca705d2e0f4a44d2@xxxxxxxxxxxxxxxxxxxxxxxxx Closes: https://syzkaller.appspot.com/bug?extid=7ea9413ea6749baf5574 [1] Closes: https://syzkaller.appspot.com/bug?extid=29b5ca705d2e0f4a44d2 [2] Signed-off-by: Ryosuke Yasuoka <ryasuoka@xxxxxxxxxx> Reviewed-by: Jeremy Cline <jeremy@xxxxxxxxxx> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c index cdad47b140fa4..0d26c8ec9993e 100644 --- a/net/nfc/nci/core.c +++ b/net/nfc/nci/core.c @@ -1516,6 +1516,11 @@ 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: