diff options
Diffstat (limited to 'kernel/user.c')
| -rw-r--r-- | kernel/user.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/kernel/user.c b/kernel/user.c index 6408c0424291..4869563080e9 100644 --- a/kernel/user.c +++ b/kernel/user.c @@ -26,7 +26,7 @@ #define __uidhashfn(uid) (((uid >> UIDHASH_BITS) + uid) & UIDHASH_MASK) #define uidhashentry(uid) (uidhash_table + __uidhashfn((uid))) -static kmem_cache_t *uid_cachep; +static struct kmem_cache *uid_cachep; static struct list_head uidhash_table[UIDHASH_SZ]; /* @@ -132,7 +132,7 @@ struct user_struct * alloc_uid(uid_t uid) if (!up) { struct user_struct *new; - new = kmem_cache_alloc(uid_cachep, SLAB_KERNEL); + new = kmem_cache_alloc(uid_cachep, GFP_KERNEL); if (!new) return NULL; new->uid = uid; @@ -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); } |