4.19-stable review patch. If anyone has any objections, please let me know.
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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 2e885b7a02a15..1f863ccf21211 100644 --- a/net/nfc/nci/core.c +++ b/net/nfc/nci/core.c @@ -1511,6 +1511,11 @@ 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: