[ 3.5.y.z extended stable ] Patch "inotify: invalid mask should return a error number but not" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    inotify: invalid mask should return a error number but not

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 125abfffbaf2c2a208417fe8f332c4b31733346e Mon Sep 17 00:00:00 2001
From: Zhao Hongjiang <zhaohongjiang at huawei.com>
Date: Tue, 30 Apr 2013 15:26:46 -0700
Subject: [PATCH] inotify: invalid mask should return a error number but not
 set it

commit 04df32fa10ab9a6f0643db2949d42efc966bc844 upstream.

When we run the crackerjack testsuite, the inotify_add_watch test is
stalled.

This is caused by the invalid mask 0 - the task is waiting for the event
but it never comes.  inotify_add_watch() should return -EINVAL as it did
before commit 676a0675cf92 ("inotify: remove broken mask checks causing
unmount to be EINVAL").  That commit removes the invalid mask check, but
that check is needed.

Check the mask's ALL_INOTIFY_BITS before the inotify_arg_to_mask() call.
If none are set, just return -EINVAL.

Because IN_UNMOUNT is in ALL_INOTIFY_BITS, this change will not trigger
the problem that above commit fixed.

[akpm at linux-foundation.org: fix build]
Signed-off-by: Zhao Hongjiang <zhaohongjiang at huawei.com>
Acked-by: Jim Somerville <Jim.Somerville at windriver.com>
Cc: Paul Gortmaker <paul.gortmaker at windriver.com>
Cc: Jerome Marchand <jmarchan at redhat.com>
Cc: Eric Paris <eparis at parisplace.org>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
[ luis: adjust context ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 fs/notify/inotify/inotify_user.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index 6f292dd..f255d37 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -577,7 +577,6 @@ static int inotify_update_existing_watch(struct fsnotify_group *group,
 	int add = (arg & IN_MASK_ADD);
 	int ret;

-	/* don't allow invalid bits: we don't want flags set */
 	mask = inotify_arg_to_mask(arg);

 	fsn_mark = fsnotify_find_inode_mark(group, inode);
@@ -628,7 +627,6 @@ static int inotify_new_watch(struct fsnotify_group *group,
 	struct idr *idr = &group->inotify_data.idr;
 	spinlock_t *idr_lock = &group->inotify_data.idr_lock;

-	/* don't allow invalid bits: we don't want flags set */
 	mask = inotify_arg_to_mask(arg);

 	tmp_i_mark = kmem_cache_alloc(inotify_inode_mark_cachep, GFP_KERNEL);
@@ -757,6 +755,10 @@ SYSCALL_DEFINE3(inotify_add_watch, int, fd, const char __user *, pathname,
 	int ret, fput_needed;
 	unsigned flags = 0;

+	/* don't allow invalid bits: we don't want flags set */
+	if (unlikely(!(mask & ALL_INOTIFY_BITS)))
+		return -EINVAL;
+
 	filp = fget_light(fd, &fput_needed);
 	if (unlikely(!filp))
 		return -EBADF;
--
1.8.1.2