From 8ff41cc21714704ef0158a546c3c4d07fae2c952 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Tue, 30 Jun 2020 14:46:15 +0300 Subject: [PATCH] net: qrtr: Fix an out of bounds read qrtr_endpoint_post() This code assumes that the user passed in enough data for a qrtr_hdr_v1 or qrtr_hdr_v2 struct, but it's not necessarily true. If the buffer is too small then it will read beyond the end. Reported-by: Manivannan Sadhasivam Reported-by: syzbot+b8fe393f999a291a9ea6@syzkaller.appspotmail.com Fixes: 194ccc88297a ("net: qrtr: Support decoding incoming v2 packets") Signed-off-by: Dan Carpenter Signed-off-by: David S. Miller --- net/qrtr/qrtr.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/net/qrtr/qrtr.c b/net/qrtr/qrtr.c index 05988133078840..24a8c3c6da0dca 100644 --- a/net/qrtr/qrtr.c +++ b/net/qrtr/qrtr.c @@ -429,7 +429,7 @@ int qrtr_endpoint_post(struct qrtr_endpoint *ep, const void *data, size_t len) unsigned int ver; size_t hdrlen; - if (len & 3) + if (len == 0 || len & 3) return -EINVAL; skb = netdev_alloc_skb(NULL, len); @@ -443,6 +443,8 @@ int qrtr_endpoint_post(struct qrtr_endpoint *ep, const void *data, size_t len) switch (ver) { case QRTR_PROTO_VER_1: + if (len < sizeof(*v1)) + goto err; v1 = data; hdrlen = sizeof(*v1); @@ -456,6 +458,8 @@ int qrtr_endpoint_post(struct qrtr_endpoint *ep, const void *data, size_t len) size = le32_to_cpu(v1->size); break; case QRTR_PROTO_VER_2: + if (len < sizeof(*v2)) + goto err; v2 = data; hdrlen = sizeof(*v2) + v2->optlen;