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* [PATCH v2] kprobes: Rollback kprobe flags on failed arm_kprobe
@ 2022-06-10 15:09 Chuang
  2022-06-12 12:31 ` Masami Hiramatsu
  0 siblings, 1 reply; 3+ messages in thread
From: Chuang @ 2022-06-10 15:09 UTC (permalink / raw)
  Cc: Chuang Wang, stable, Jingren Zhou, Naveen N. Rao,
	Anil S Keshavamurthy, David S. Miller, Masami Hiramatsu,
	Ingo Molnar, Jessica Yu, linux-kernel

From: Chuang Wang <nashuiliang@gmail.com>

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

Fixes: 12310e343755 ("kprobes: Propagate error from arm_kprobe_ftrace()")
Signed-off-by: Chuang Wang <nashuiliang@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jingren Zhou <zhoujingren@didiglobal.com>
---
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


^ permalink raw reply related	[flat|nested] 3+ messages in thread
* Re: [PATCH v2] kprobes: Rollback kprobe flags on failed arm_kprobe
  2022-06-10 15:09 [PATCH v2] kprobes: Rollback kprobe flags on failed arm_kprobe Chuang
@ 2022-06-12 12:31 ` Masami Hiramatsu
  0 siblings, 0 replies; 3+ messages in thread
From: Masami Hiramatsu @ 2022-06-12 12:31 UTC (permalink / raw)
  To: Chuang
  Cc: stable, Jingren Zhou, Naveen N. Rao, Anil S Keshavamurthy,
	David S. Miller, Masami Hiramatsu, Ingo Molnar, Jessica Yu,
	linux-kernel

On Fri, 10 Jun 2022 23:09:33 +0800
Chuang <nashuiliang@gmail.com> wrote:

> From: Chuang Wang <nashuiliang@gmail.com>
> 
> 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@kernel.org>

Thanks for update!

> Fixes: 12310e343755 ("kprobes: Propagate error from arm_kprobe_ftrace()")
> Signed-off-by: Chuang Wang <nashuiliang@gmail.com>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Jingren Zhou <zhoujingren@didiglobal.com>
> ---
> 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@kernel.org>

^ permalink raw reply	[flat|nested] 3+ messages in thread
* [PATCH v2] kprobes: Rollback kprobe flags on failed arm_kprobe
@ 2022-06-08  2:12 Chuang
  0 siblings, 0 replies; 3+ messages in thread
From: Chuang @ 2022-06-08  2:12 UTC (permalink / raw)
  Cc: Chuang Wang, stable, Jingren Zhou, Naveen N. Rao,
	Anil S Keshavamurthy, David S. Miller, Masami Hiramatsu,
	Jessica Yu, Ingo Molnar, linux-kernel

From: Chuang Wang <nashuiliang@gmail.com>

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

Fixes: 12310e343755 ("kprobes: Propagate error from arm_kprobe_ftrace()")
Cc: stable@vger.kernel.org
Signed-off-by: Jingren Zhou <zhoujingren@didiglobal.com>
Signed-off-by: Chuang Wang <nashuiliang@gmail.com>

---
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


^ permalink raw reply related	[flat|nested] 3+ messages in thread
end of thread, other threads:[~2022-06-12 12:32 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2022-06-10 15:09 [PATCH v2] kprobes: Rollback kprobe flags on failed arm_kprobe Chuang
2022-06-12 12:31 ` Masami Hiramatsu
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2022-06-08  2:12 Chuang

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