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authorAni Sinha <ani@arista.com>2014-09-08 14:49:59 -0700
committerStefan Bader <stefan.bader@canonical.com>2015-05-29 11:54:15 +0200
commit6db6e344e6dfc835199f28b8b9d7732e95cc077f (patch)
tree3111fcee922c86e1bad765538627536f283b1371
parentac93923b962d52e348f9e4c80cb67a3553615fc3 (diff)
downloadlinux-2.6.32.y-drm33.z-6db6e344e6dfc835199f28b8b9d7732e95cc077f.tar.gz
net:socket: set msg_namelen to 0 if msg_name is passed as NULL in msghdr struct from userland.
commit 6a2a2b3ae0759843b22c929881cc184b00cc63ff upstream. Linux manpage for recvmsg and sendmsg calls does not explicitly mention setting msg_namelen to 0 when msg_name passed set as NULL. When developers don't set msg_namelen member in msghdr, it might contain garbage value which will fail the validation check and sendmsg and recvmsg calls from kernel will return EINVAL. This will break old binaries and any code for which there is no access to source code. To fix this, we set msg_namelen to 0 when msg_name is passed as NULL from userland. Signed-off-by: Ani Sinha <ani@arista.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> (cherry picked from commit d29f1f53e5299e0bbb3e33ef8d35ed657fa633b6) Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
-rw-r--r--net/socket.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/net/socket.c b/net/socket.c
index 19671d8e20f682..a838a67dd77d4d 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1872,6 +1872,9 @@ static int copy_msghdr_from_user(struct msghdr *kmsg,
if (copy_from_user(kmsg, umsg, sizeof(struct msghdr)))
return -EFAULT;
+ if (kmsg->msg_name == NULL)
+ kmsg->msg_namelen = 0;
+
if (kmsg->msg_namelen < 0)
return -EINVAL;