From: Young Xiao <92siuyang@gmail.com>
To: davem@davemloft.net, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Cc: Young Xiao <92siuyang@gmail.com>
Subject: [PATCH] net: compat: fix msg_controllen overflow in scm_detach_fds_compat()
Date: Tue, 4 Jun 2019 20:31:45 +0800 [thread overview]
Message-ID: <1559651505-18137-1-git-send-email-92siuyang@gmail.com> (raw)
There is a missing check between kmsg->msg_controllen and cmlen,
which can possibly lead to overflow.
This bug is similar to vulnerability that was fixed in commit 6900317f5eff
("net, scm: fix PaX detected msg_controllen overflow in scm_detach_fds").
Signed-off-by: Young Xiao <92siuyang@gmail.com>
---
net/compat.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/net/compat.c b/net/compat.c
index a031bd3..8e74dfb 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -301,6 +301,8 @@ void scm_detach_fds_compat(struct msghdr *kmsg, struct scm_cookie *scm)
err = put_user(cmlen, &cm->cmsg_len);
if (!err) {
cmlen = CMSG_COMPAT_SPACE(i * sizeof(int));
+ if (kmsg->msg_controllen < cmlen)
+ cmlen = kmsg->msg_controllen;
kmsg->msg_control += cmlen;
kmsg->msg_controllen -= cmlen;
}
--
2.7.4
next reply other threads:[~2019-06-04 12:30 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-04 12:31 Young Xiao [this message]
2019-06-04 12:46 ` [PATCH] net: compat: fix msg_controllen overflow in scm_detach_fds_compat() Daniel Borkmann
2019-06-04 12:54 ` Yang Xiao
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