[ 060/136 ] inotify: invalid mask should return a error number but not set it

Steven Rostedt
2013-05-18T02:18:29Z

[-- Attachment #1: 0060-inotify-invalid-mask-should-return-a-error-number-bu.patch --]
[-- Type: text/plain, Size: 2589 bytes --]

3.6.11.4 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Zhao Hongjiang <zhaohongjiang@huawei.com>

[ Upstream commit 04df32fa10ab9a6f0643db2949d42efc966bc844 ]

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>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
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 8445fbc..7e15ab0 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);
if (unlikely(!(mask & IN_ALL_EVENTS)))
return -EINVAL;
@@ -630,7 +629,6 @@ 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);
if (unlikely(!(mask & IN_ALL_EVENTS)))
return -EINVAL;
@@ -761,6 +759,10 @@ 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;
--
1.7.10.4