linux-kernel - [PATCH] net: compat: Update get_compat_msghdr() to match copy_msghdr_from

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 20 Mar 2015 16:48:13 +0000
From:	Catalin Marinas <catalin.marinas@....com>
To:	netdev@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org, Will Deacon <will.deacon@....com>,
	"David S. Miller" <davem@...emloft.net>,
	Dan Carpenter <dan.carpenter@...cle.com>
Subject: [PATCH] net: compat: Update get_compat_msghdr() to match copy_msghdr_from_user() behaviour

Commit db31c55a6fb2 (net: clamp ->msg_namelen instead of returning an
error) introduced the clamping of msg_namelen when the unsigned value
was larger than sizeof(struct sockaddr_storage). This caused a
msg_namelen of -1 to be valid. The native code was subsequently fixed by
commit dbb490b96584 (net: socket: error on a negative msg_namelen).

In addition, the native code sets msg_namelen to 0 when msg_name is
NULL. This was done in commit (6a2a2b3ae075 net:socket: set msg_namelen
to 0 if msg_name is passed as NULL in msghdr struct from userland) and
subsequently updated by 08adb7dabd48 (fold verify_iovec() into
copy_msghdr_from_user()).

This patch brings the get_compat_msghdr() in line with
copy_msghdr_from_user().

Fixes: db31c55a6fb2 (net: clamp ->msg_namelen instead of returning an error)
Cc: David S. Miller <davem@...emloft.net>
Cc: Dan Carpenter <dan.carpenter@...cle.com>
Signed-off-by: Catalin Marinas <catalin.marinas@....com>
---
 net/compat.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/net/compat.c b/net/compat.c
index 94d3d5e97883..f7bd286a8280 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -49,6 +49,13 @@ ssize_t get_compat_msghdr(struct msghdr *kmsg,
 	    __get_user(kmsg->msg_controllen, &umsg->msg_controllen) ||
 	    __get_user(kmsg->msg_flags, &umsg->msg_flags))
 		return -EFAULT;
+
+	if (!uaddr)
+		kmsg->msg_namelen = 0;
+
+	if (kmsg->msg_namelen < 0)
+		return -EINVAL;
+
 	if (kmsg->msg_namelen > sizeof(struct sockaddr_storage))
 		kmsg->msg_namelen = sizeof(struct sockaddr_storage);
 	kmsg->msg_control = compat_ptr(tmp3);
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/