3.16.7-ckt13 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Junling Zheng <zhengjunling@xxxxxxxxxx>
Based on 08adb7dabd4874cc5666b4490653b26534702ce0 upstream.
Commit 281c9c36 (net: compat: Update get_compat_msghdr() to match
copy_msghdr_from_user() behaviour) made get_compat_msghdr() return
error if msg_sys->msg_namelen was negative, which changed the behaviors
of recvmsg and sendmsg syscall in a lib32 system:
Before commit 281c9c36, get_compat_msghdr() wouldn't fail and it would
return -EINVAL in move_addr_to_user() or somewhere if msg_sys->msg_namelen
was invalid and then syscall returned -EINVAL, which is correct.
And now, when msg_sys->msg_namelen is negative, get_compat_msghdr() will
fail and wants to return -EINVAL, however, the outer syscall will return
-EFAULT directly, which is unexpected.
This patch gets the return value of get_compat_msghdr() as well as
copy_msghdr_from_user(), then returns this expected value if
get_compat_msghdr() fails.
Fixes: 281c9c36 (net: compat: Update get_compat_msghdr() to match copy_msghdr_from_user() behaviour)
Signed-off-by: Junling Zheng <zhengjunling@xxxxxxxxxx>
Signed-off-by: Hanbing Xu <xuhanbing@xxxxxxxxxx>
Cc: Li Zefan <lizefan@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: David Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
net/socket.c | 24 ++++++++++--------------
1 file changed, 10 insertions(+), 14 deletions(-)
diff --git a/net/socket.c b/net/socket.c
index 4980af97d87c..fc7ba8cabb72 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2011,14 +2011,12 @@ static int ___sys_sendmsg(struct socket *sock, struct msghdr __user *msg,
int err, ctl_len, total_len;
err = -EFAULT;
- if (MSG_CMSG_COMPAT & flags) {
- if (get_compat_msghdr(msg_sys, msg_compat))
- return -EFAULT;
- } else {
+ if (MSG_CMSG_COMPAT & flags)
+ err = get_compat_msghdr(msg_sys, msg_compat);
+ else
err = copy_msghdr_from_user(msg_sys, msg);
- if (err)
- return err;
- }
+ if (err)
+ return err;
if (msg_sys->msg_iovlen > UIO_FASTIOV) {
err = -EMSGSIZE;
@@ -2223,14 +2221,12 @@ static int ___sys_recvmsg(struct socket *sock, struct msghdr __user *msg,
struct sockaddr __user *uaddr;
int __user *uaddr_len;
- if (MSG_CMSG_COMPAT & flags) {
- if (get_compat_msghdr(msg_sys, msg_compat))
- return -EFAULT;
- } else {
+ if (MSG_CMSG_COMPAT & flags)
+ err = get_compat_msghdr(msg_sys, msg_compat);
+ else
err = copy_msghdr_from_user(msg_sys, msg);
- if (err)
- return err;
- }
+ if (err)
+ return err;
if (msg_sys->msg_iovlen > UIO_FASTIOV) {
err = -EMSGSIZE;
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html