diff options
| author | Nick Piggin <npiggin@suse.de> | 2007-02-12 00:51:59 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-02-12 09:48:28 -0800 |
| commit | f9e4acf3befd3b2903e01b3ef1bd344f03299826 (patch) | |
| tree | 26eb1f9e71adfd4bd5678861c8f13fd655adfa60 | |
| parent | d003fb70fd356d0684ee0cd37a785e058c8678de (diff) | |
[PATCH] inotify: read return val fix
Fix for inotify read bug (bugzilla.kernel.org #6999)
Problem Description:
When reading from an inotify device with an insufficient sized buffer, read(2)
will return 0 with no errno set. This is because of an logically incorrect
action from the user program thus should return an more logical value. My
suggestion is return -EINVAL as for bind(2).
This patch is based on the proposal from Ryan <wolf0403@hotmail.com>, and
feedback from John McCutchan <john@johnmccutchan.com>.
Return -EINVAL if we have not passed in enough buffer space to read a single
inotify event, rather than 0 which indicates that there is nothing to read.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: "John McCutchan" <john@johnmccutchan.com>
Cc: Ryan <wolf0403@hotmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/inotify_user.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/fs/inotify_user.c b/fs/inotify_user.c index 55f6da55b7c0..9f2224f65a18 100644 --- a/fs/inotify_user.c +++ b/fs/inotify_user.c @@ -455,8 +455,16 @@ static ssize_t inotify_read(struct file *file, char __user *buf, break; kevent = inotify_dev_get_event(dev); - if (event_size + kevent->event.len > count) + if (event_size + kevent->event.len > count) { + if (ret == 0 && count > 0) { + /* + * could not get a single event because we + * didn't have enough buffer space. + */ + ret = -EINVAL; + } break; + } if (copy_to_user(buf, &kevent->event, event_size)) { ret = -EFAULT; |