Masami,
Care to review? Thanks! -- Steve On Thu, 28 Jan 2021 20:44:27 +0800 Wang ShaoBo <[email protected]> wrote: > 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. > > Signed-off-by: Wang ShaoBo <[email protected]> > Signed-off-by: Cheng Jian <[email protected]> > --- > kernel/kprobes.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > index f7fb5d135930..5c4a884953e9 100644 > --- a/kernel/kprobes.c > +++ b/kernel/kprobes.c > @@ -1978,6 +1978,10 @@ 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))
