[ 078/104] inotify: invalid mask should return a error number but not set it

Greg Kroah-Hartman
2013-05-06T23:22:36Z

From: Zhao Hongjiang <zhaohongjiang@huawei.com>

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@linux-foundation.org: fix build]
Signed-off-by: Zhao Hongjiang <zhaohongjiang@huawei.com>
Acked-by: Jim Somerville <Jim.Somerville@windriver.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Eric Paris <eparis@parisplace.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/notify/inotify/inotify_user.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -574,7 +574,6 @@ static int inotify_update_existing_watch
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);
@@ -625,7 +624,6 @@ static int inotify_new_watch(struct fsno
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);
@@ -753,6 +751,10 @@ SYSCALL_DEFINE3(inotify_add_watch, int,
int ret;
unsigned flags = 0;

+ /* don't allow invalid bits: we don't want flags set */
+ if (unlikely(!(mask & ALL_INOTIFY_BITS)))
+ return -EINVAL;
+
f = fdget(fd);
if (unlikely(!f.file))
return -EBADF;