Messages in this thread Patch in this message | | | From | Muchun Song <> | Subject | [PATCH] kprobes: Fix kill kprobe which has been marked as gone | Date | Thu, 20 Aug 2020 11:19:33 +0800 |
| |
If a kprobe is marked as gone, we should not kill it again. Otherwise, we can disarm the kprobe more than once. In that case, the statistics of kprobe_ftrace_enabled can unbalance which can lead to that kprobe do not work.
Fixes: 0cb2f1372baa ("kprobes: Fix NULL pointer dereference at kprobe_ftrace_handler") Signed-off-by: Muchun Song <songmuchun@bytedance.com> Co-developed-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> --- kernel/kprobes.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index d36e2b017588..7bac3ea44ff4 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -2422,7 +2422,10 @@ static int kprobes_module_callback(struct notifier_block *nb, mutex_lock(&kprobe_mutex); for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; - hlist_for_each_entry(p, head, hlist) + hlist_for_each_entry(p, head, hlist) { + if (kprobe_gone(p)) + continue; + if (within_module_init((unsigned long)p->addr, mod) || (checkcore && within_module_core((unsigned long)p->addr, mod))) { @@ -2439,6 +2442,7 @@ static int kprobes_module_callback(struct notifier_block *nb, */ kill_kprobe(p); } + } } if (val == MODULE_STATE_GOING) remove_module_kprobe_blacklist(mod); -- 2.11.0
| |