On Fri, 10 Jun 2022 23:09:33 +0800
Chuang <nashuiliang@xxxxxxxxx> wrote:
> From: Chuang Wang <nashuiliang@xxxxxxxxx>
>
> In aggrprobe scenes, if arm_kprobe() returns an error(e.g. livepatch and
> kprobe are using the same function X), kprobe flags, while has been
> modified to ~KPROBE_FLAG_DISABLED, is not rollled back.
>
> Then, __disable_kprobe() will be failed in __unregister_kprobe_top(),
> the kprobe list will be not removed from aggrprobe, memory leaks or
> illegal pointers will be caused.
>
> WARN disarm_kprobe:
> Failed to disarm kprobe-ftrace at 00000000c729fdbc (-2)
> RIP: 0010:disarm_kprobe+0xcc/0x110
> Call Trace:
> __disable_kprobe+0x78/0x90
> __unregister_kprobe_top+0x13/0x1b0
> ? _cond_resched+0x15/0x30
> unregister_kprobes+0x32/0x80
> unregister_kprobe+0x1a/0x20
>
> Illegal Pointers:
> BUG: unable to handle kernel paging request at 0000000000656369
> RIP: 0010:__get_valid_kprobe+0x69/0x90
> Call Trace:
> register_kprobe+0x30/0x60
> __register_trace_kprobe.part.7+0x8b/0xc0
> create_local_trace_kprobe+0xd2/0x130
> perf_kprobe_init+0x83/0xd0
>
This looks good to me.
Acked-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
Thanks for update!
> Fixes: 12310e343755 ("kprobes: Propagate error from arm_kprobe_ftrace()")
> Signed-off-by: Chuang Wang <nashuiliang@xxxxxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Jingren Zhou <zhoujingren@xxxxxxxxxxxxxx>
> ---
> v1->v2:
> - Supplement commit information: fixline, Cc stable
>
> kernel/kprobes.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
> index f214f8c088ed..c11c79e05a4c 100644
> --- a/kernel/kprobes.c
> +++ b/kernel/kprobes.c
> @@ -2422,8 +2422,11 @@ int enable_kprobe(struct kprobe *kp)
> if (!kprobes_all_disarmed && kprobe_disabled(p)) {
> p->flags &= ~KPROBE_FLAG_DISABLED;
> ret = arm_kprobe(p);
> - if (ret)
> + if (ret) {
> p->flags |= KPROBE_FLAG_DISABLED;
> + if (p != kp)
> + kp->flags |= KPROBE_FLAG_DISABLED;
> + }
> }
> out:
> mutex_unlock(&kprobe_mutex);
> --
> 2.34.1
>
--
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
