Messages in this thread | | | Date | Mon, 08 Sep 2014 10:24:54 -0400 | From | Sasha Levin <> | Subject | Re: [PATCH] fsnotify: don't put user context if it was never assigned |
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Ping?
On 09/03/2014 05:31 PM, Sasha Levin wrote: > Ping? This is a NULL ptr deref that userspace can trigger. > > On 07/29/2014 09:25 AM, Sasha Levin wrote: >> On some failure paths we may attempt to free user context even >> if it wasn't assigned yet. This will cause a NULL ptr deref >> and a kernel BUG. >> >> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> >> --- >> fs/notify/inotify/inotify_fsnotify.c | 6 ++++-- >> 1 file changed, 4 insertions(+), 2 deletions(-) >> >> diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c >> index 43ab1e1..9c8187e 100644 >> --- a/fs/notify/inotify/inotify_fsnotify.c >> +++ b/fs/notify/inotify/inotify_fsnotify.c >> @@ -165,8 +165,10 @@ static void inotify_free_group_priv(struct fsnotify_group *group) >> /* ideally the idr is empty and we won't hit the BUG in the callback */ >> idr_for_each(&group->inotify_data.idr, idr_callback, group); >> idr_destroy(&group->inotify_data.idr); >> - atomic_dec(&group->inotify_data.user->inotify_devs); >> - free_uid(group->inotify_data.user); >> + if (group->inotify_data.user) { >> + atomic_dec(&group->inotify_data.user->inotify_devs); >> + free_uid(group->inotify_data.user); >> + } >> } >> >> static void inotify_free_event(struct fsnotify_event *fsn_event) >> >
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