From ad9d24c9429e2159d1e279dc3a83191ccb4daf1d Mon Sep 17 00:00:00 2001 From: Pavel Skripkin Date: Mon, 14 Jun 2021 15:06:50 +0300 Subject: net: qrtr: fix OOB Read in qrtr_endpoint_post Syzbot reported slab-out-of-bounds Read in qrtr_endpoint_post. The problem was in wrong _size_ type: if (len != ALIGN(size, 4) + hdrlen) goto err; If size from qrtr_hdr is 4294967293 (0xfffffffd), the result of ALIGN(size, 4) will be 0. In case of len == hdrlen and size == 4294967293 in header this check won't fail and skb_put_data(skb, data + hdrlen, size); will read out of bound from data, which is hdrlen allocated block. Fixes: 194ccc88297a ("net: qrtr: Support decoding incoming v2 packets") Reported-and-tested-by: syzbot+1917d778024161609247@syzkaller.appspotmail.com Signed-off-by: Pavel Skripkin Reviewed-by: Bjorn Andersson Signed-off-by: David S. Miller --- net/qrtr/qrtr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/qrtr/qrtr.c b/net/qrtr/qrtr.c index c0477bec09bd..f2efaa4225f9 100644 --- a/net/qrtr/qrtr.c +++ b/net/qrtr/qrtr.c @@ -436,7 +436,7 @@ int qrtr_endpoint_post(struct qrtr_endpoint *ep, const void *data, size_t len) struct qrtr_sock *ipc; struct sk_buff *skb; struct qrtr_cb *cb; - unsigned int size; + size_t size; unsigned int ver; size_t hdrlen; -- cgit v1.2.3