From d0f36951ead4a5fc8411fbdf206cd4f18ead5963 Mon Sep 17 00:00:00 2001 From: Wang ShaoBo Date: Thu, 28 Jan 2021 20:44:27 +0800 Subject: kretprobe: Avoid re-registration of the same kretprobe earlier commit 0188b87899ffc4a1d36a0badbe77d56c92fd91dc upstream. Our system encountered a re-init error when re-registering same kretprobe, where the kretprobe_instance in rp->free_instances is illegally accessed after re-init. Implementation to avoid re-registration has been introduced for kprobe before, but lags for register_kretprobe(). We must check if kprobe has been re-registered before re-initializing kretprobe, otherwise it will destroy the data struct of kretprobe registered, which can lead to memory leak, system crash, also some unexpected behaviors. We use check_kprobe_rereg() to check if kprobe has been re-registered before running register_kretprobe()'s body, for giving a warning message and terminate registration process. Link: https://lkml.kernel.org/r/20210128124427.2031088-1-bobo.shaobowang@huawei.com Cc: stable@vger.kernel.org Fixes: 1f0ab40976460 ("kprobes: Prevent re-registration of the same kprobe") [ The above commit should have been done for kretprobes too ] Acked-by: Naveen N. Rao Acked-by: Ananth N Mavinakayanahalli Acked-by: Masami Hiramatsu Signed-off-by: Wang ShaoBo Signed-off-by: Cheng Jian Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Greg Kroah-Hartman --- kernel/kprobes.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 283c8b01ce78..26ae92c12fc2 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1972,6 +1972,10 @@ int register_kretprobe(struct kretprobe *rp) if (!kprobe_on_func_entry(rp->kp.addr, rp->kp.symbol_name, rp->kp.offset)) return -EINVAL; + /* If only rp->kp.addr is specified, check reregistering kprobes */ + if (rp->kp.addr && check_kprobe_rereg(&rp->kp)) + return -EINVAL; + if (kretprobe_blacklist_size) { addr = kprobe_addr(&rp->kp); if (IS_ERR(addr)) -- cgit v1.2.3