diff options
| -rw-r--r-- | kernel/user.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/kernel/user.c b/kernel/user.c index 6408c0424291..220e586127a0 100644 --- a/kernel/user.c +++ b/kernel/user.c @@ -187,6 +187,17 @@ void switch_uid(struct user_struct *new_user) atomic_dec(&old_user->processes); switch_uid_keyring(new_user); current->user = new_user; + + /* + * We need to synchronize with __sigqueue_alloc() + * doing a get_uid(p->user).. If that saw the old + * user value, we need to wait until it has exited + * its critical region before we can free the old + * structure. + */ + smp_mb(); + spin_unlock_wait(¤t->sighand->siglock); + free_uid(old_user); suid_keys(current); } |