From: Chen Zhongjin Date: Mon, 1 Aug 2022 03:37:19 +0000 (+0800) Subject: kprobes: Forbid probing on trampoline and BPF code areas X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=4262b6eb057d86c7829168c541654fe0d48fdac8;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git kprobes: Forbid probing on trampoline and BPF code areas [ Upstream commit 28f6c37a2910f565b4f5960df52b2eccae28c891 ] kernel_text_address() treats ftrace_trampoline, kprobe_insn_slot and bpf_text_address as valid kprobe addresses - which is not ideal. These text areas are removable and changeable without any notification to kprobes, and probing on them can trigger unexpected behavior: https://lkml.org/lkml/2022/7/26/1148 Considering that jump_label and static_call text are already forbiden to probe, kernel_text_address() should be replaced with core_kernel_text() and is_module_text_address() to check other text areas which are unsafe to kprobe. [ mingo: Rewrote the changelog. ] Fixes: 5b485629ba0d ("kprobes, extable: Identify kprobes trampolines as kernel text area") Fixes: 74451e66d516 ("bpf: make jited programs visible in traces") Signed-off-by: Chen Zhongjin Signed-off-by: Ingo Molnar Acked-by: Masami Hiramatsu (Google) Link: https://lore.kernel.org/r/20220801033719.228248-1-chenzhongjin@huawei.com Signed-off-by: Sasha Levin --- diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 4f918dd28fb7..b8e14aa6d496 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1551,7 +1551,8 @@ static int check_kprobe_address_safe(struct kprobe *p, preempt_disable(); /* Ensure it is not in reserved area nor out of text */ - if (!kernel_text_address((unsigned long) p->addr) || + if (!(core_kernel_text((unsigned long) p->addr) || + is_module_text_address((unsigned long) p->addr)) || within_kprobe_blacklist((unsigned long) p->addr) || jump_label_text_reserved(p->addr, p->addr) || find_bug((unsigned long)p->addr)) {