Re: [PATCH] net: qrtr: fix OOB Read in qrtr_endpoint_post
From: Bjorn Andersson <hidden>
Date: 2021-06-14 15:59:02
Also in:
linux-arm-msm, lkml
On Mon 14 Jun 07:06 CDT 2021, Pavel Skripkin wrote:
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 <redacted>Reviewed-by: Bjorn Andersson <redacted> Regards, Bjorn
quoted hunk ↗ jump to hunk
--- 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;-- 2.32.0