[PATCH] net: clear msg_get_inq in __get_compat_msghdr()

syzbot is still complaining uninit-value in tcp_recvmsg(), for
commit 1228b34c8d0ecf6d ("net: clear msg_get_inq in __sys_recvfrom() and
__copy_msghdr_from_user()") missed that __get_compat_msghdr() is called
instead of copy_msghdr_from_user() when MSG_CMSG_COMPAT is specified.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: 1228b34c8d0ecf6d ("net: clear msg_get_inq in __sys_recvfrom() and __copy_msghdr_from_user()")
---
 net/compat.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/compat.c b/net/compat.c
index fe9be3c56ef7..385f04a6be2f 100644
--- a/net/compat.c
+++ b/net/compat.c

@@ -52,6 +52,7 @@ int __get_compat_msghdr(struct msghdr *kmsg,
 		kmsg->msg_namelen = sizeof(struct sockaddr_storage);
 
 	kmsg->msg_control_is_user = true;
+	kmsg->msg_get_inq = 0;
 	kmsg->msg_control_user = compat_ptr(msg->msg_control);
 	kmsg->msg_controllen = msg->msg_controllen;
 

-- 
2.18.4

On 9/14/22 3:51 AM, Tetsuo Handa wrote:

syzbot is still complaining uninit-value in tcp_recvmsg(), for
commit 1228b34c8d0ecf6d ("net: clear msg_get_inq in __sys_recvfrom() and
__copy_msghdr_from_user()") missed that __get_compat_msghdr() is called
instead of copy_msghdr_from_user() when MSG_CMSG_COMPAT is specified.

Looks good to me:

Reviewed-by: Jens Axboe <axboe@kernel.dk>

-- 
Jens Axboe

Hello:

This patch was applied to netdev/net.git (master)
by Jakub Kicinski [off-list ref]:

On Wed, 14 Sep 2022 18:51:54 +0900 you wrote:

syzbot is still complaining uninit-value in tcp_recvmsg(), for
commit 1228b34c8d0ecf6d ("net: clear msg_get_inq in __sys_recvfrom() and
__copy_msghdr_from_user()") missed that __get_compat_msghdr() is called
instead of copy_msghdr_from_user() when MSG_CMSG_COMPAT is specified.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: 1228b34c8d0ecf6d ("net: clear msg_get_inq in __sys_recvfrom() and __copy_msghdr_from_user()")

[...]

Here is the summary with links:
  - net: clear msg_get_inq in __get_compat_msghdr()
    https://git.kernel.org/netdev/net/c/d547c1b717fc

You are awesome, thank you!
-- 
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