[PATCH] kprobes: Rollback kprobe flags on failed arm_kprobe
From: Chuang
Date: Thu Jun 02 2022 - 03:33:38 EST
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
Signed-off-by: Chuang Wang <nashuiliang@xxxxxxxxx>
Signed-off-by: Jingren Zhou <zhoujingren@xxxxxxxxxxxxxx>
---
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