[PATCH 03/26] bpfilter: reject kernel addresses
From: Christoph Hellwig <hch@lst.de>
Date: 2020-07-23 06:13:54
Also in:
bpf, bridge, linux-bluetooth, linux-can, linux-crypto, linux-hams, linux-s390, linux-sctp, lkml, lvs-devel, mptcp, netfilter-devel
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
The bpfilter user mode helper processes the optval address using process_vm_readv. Don't send it kernel addresses fed under set_fs(KERNEL_DS) as that won't work. Signed-off-by: Christoph Hellwig <hch@lst.de> --- net/bpfilter/bpfilter_kern.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/net/bpfilter/bpfilter_kern.c b/net/bpfilter/bpfilter_kern.c
index 78d561f2c54da7..00540457e5f4d3 100644
--- a/net/bpfilter/bpfilter_kern.c
+++ b/net/bpfilter/bpfilter_kern.c@@ -70,6 +70,10 @@ static int bpfilter_process_sockopt(struct sock *sk, int optname, .addr = (uintptr_t)optval, .len = optlen, }; + if (uaccess_kernel()) { + pr_err("kernel access not supported\n"); + return -EFAULT; + } return bpfilter_send_req(&req); }
--
2.27.0