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| author | Masami Hiramatsu <mhiramat@kernel.org> | 2020-09-01 00:12:07 +0900 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2020-09-14 11:20:03 +0200 |
| commit | bcb53209be5cb32d485507452edda19b78f31d84 (patch) | |
| tree | cd0a53bcb9b0672442e3436bc6c14f3835e3503d | |
| parent | 319f0ce284fff8e4f95167cb144acc905d0584c7 (diff) | |
| download | linux-bcb53209be5cb32d485507452edda19b78f31d84.tar.bz2 | |
kprobes: Fix to check probe enabled before disarm_kprobe_ftrace()
Commit:
0cb2f1372baa ("kprobes: Fix NULL pointer dereference at kprobe_ftrace_handler")
fixed one bug but the underlying bugs are not completely fixed yet.
If we run a kprobe_module.tc of ftracetest, a warning triggers:
# ./ftracetest test.d/kprobe/kprobe_module.tc
=== Ftrace unit tests ===
[1] Kprobe dynamic event - probing module
...
------------[ cut here ]------------
Failed to disarm kprobe-ftrace at trace_printk_irq_work+0x0/0x7e [trace_printk] (-2)
WARNING: CPU: 7 PID: 200 at kernel/kprobes.c:1091 __disarm_kprobe_ftrace.isra.0+0x7e/0xa0
This is because the kill_kprobe() calls disarm_kprobe_ftrace() even
if the given probe is not enabled. In that case, ftrace_set_filter_ip()
fails because the given probe point is not registered to ftrace.
Fix to check the given (going) probe is enabled before invoking
disarm_kprobe_ftrace().
Fixes: 0cb2f1372baa ("kprobes: Fix NULL pointer dereference at kprobe_ftrace_handler")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/159888672694.1411785.5987998076694782591.stgit@devnote2
| -rw-r--r-- | kernel/kprobes.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 732a70163584..3b61ae8ff5da 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -2235,9 +2235,10 @@ static void kill_kprobe(struct kprobe *p) /* * The module is going away. We should disarm the kprobe which - * is using ftrace. + * is using ftrace, because ftrace framework is still available at + * MODULE_STATE_GOING notification. */ - if (kprobe_ftrace(p)) + if (kprobe_ftrace(p) && !kprobe_disabled(p) && !kprobes_all_disarmed) disarm_kprobe_ftrace(p); } |