CVE-2021-47240 Information

Description

In the Linux kernel the following vulnerability has been resolved:

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.

Reference

https://git.kernel.org/stable/c/f8111c0d7ed42ede41a3d0d393b104de0730a8a6 https://git.kernel.org/stable/c/26b8d10703a9be45d6097946b2b4011f7dd2c56f https://git.kernel.org/stable/c/960b08dd36de1e341e3eb43d1c547513e338f4f8 https://git.kernel.org/stable/c/19892ab9c9d838e2e5a7744d36e4bb8b7c3292fe https://git.kernel.org/stable/c/ad9d24c9429e2159d1e279dc3a83191ccb4daf1d