Messages in this thread Patch in this message | | | From | Chuang <> | Subject | [PATCH] kprobes: Rollback kprobe flags on failed arm_kprobe | Date | Thu, 2 Jun 2022 15:32:59 +0800 |
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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
Signed-off-by: Chuang Wang <nashuiliang@gmail.com> Signed-off-by: Jingren Zhou <zhoujingren@didiglobal.com> --- kernel/kprobes.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index f214f8c088ed..96c75e23113c 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -2422,8 +2422,10 @@ 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; + kp->flags |= KPROBE_FLAG_DISABLED; + } } out: mutex_unlock(&kprobe_mutex); -- 2.34.1
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