diff options
Diffstat (limited to 'kernel/events/uprobes.c')
| -rw-r--r-- | kernel/events/uprobes.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index bf2a87a0a378..b4ca8898fe17 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -495,6 +495,11 @@ retry: if (ret <= 0) goto put_old; + if (is_zero_page(old_page)) { + ret = -EINVAL; + goto put_old; + } + if (WARN(!is_register && PageCompound(old_page), "uprobe unregister should never work on compound page\n")) { ret = -EINVAL; @@ -762,10 +767,14 @@ static struct uprobe *hprobe_expire(struct hprobe *hprobe, bool get) enum hprobe_state hstate; /* - * return_instance's hprobe is protected by RCU. - * Underlying uprobe is itself protected from reuse by SRCU. + * Caller should guarantee that return_instance is not going to be + * freed from under us. This can be achieved either through holding + * rcu_read_lock() or by owning return_instance in the first place. + * + * Underlying uprobe is itself protected from reuse by SRCU, so ensure + * SRCU lock is held properly. */ - lockdep_assert(rcu_read_lock_held() && srcu_read_lock_held(&uretprobes_srcu)); + lockdep_assert(srcu_read_lock_held(&uretprobes_srcu)); hstate = READ_ONCE(hprobe->state); switch (hstate) { |