Patch "autofs: Fix automounts by using current_real_cred()->uid" has been added to the 4.8-stable tree

This is a note to let you know that I've just added the patch titled

    autofs:  Fix automounts by using current_real_cred()->uid

to the 4.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
autofs-fix-automounts-by-using-current_real_cred-uid.patch
and it can be found in the queue-4.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: "Eric W. Biederman" <[email protected]>
Date: Fri, 30 Sep 2016 11:28:05 -0500
Subject: autofs: Fix automounts by using current_real_cred()->uid

From: Eric W. Biederman <[email protected]>

commit 069d5ac9ae0d271903cc4607890616418118379a upstream.

Seth Forshee reports that in 4.8-rcN some automounts are failing because the requesting the automount changed.

The relevant call path is:
follow_automount()

    ->d_automount
    autofs4_d_automount
       autofs4_mount_wait
           autofs4_wait

In autofs4_wait wq_uid and wq_gid are set to current_uid() and current_gid respectively. With follow_automount now overriding creds uid that we export to userspace changes and that breaks existing setups.

To remove the regression set wq_uid and wq_gid from current_real_cred()->uid and current_real_cred()->gid respectively. This restores the current behavior as current->real_cred is identical to current->cred except when override creds are used.

---
 fs/autofs4/waitq.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

@@ -431,8 +431,8 @@ int autofs4_wait(struct autofs_sb_info *
 		memcpy(&wq->name, &qstr, sizeof(struct qstr));
 		wq->dev = autofs4_get_dev(sbi);
 		wq->ino = autofs4_get_ino(sbi);
-		wq->uid = current_uid();
-		wq->gid = current_gid();
+		wq->uid = current_real_cred()->uid;
+		wq->gid = current_real_cred()->gid;
 		wq->pid = pid;
 		wq->tgid = tgid;
 		wq->status = -EINTR; /* Status return if interrupted */

Patches currently in stable-queue which might be from [email protected] are

queue-4.8/autofs-fix-automounts-by-using-current_real_cred-uid.patch