linux-kernel - [PATCH] x86/ibt: make is

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250918120939.1706585-1-dongml2@chinatelecom.cn>
Date: Thu, 18 Sep 2025 20:09:39 +0800
From: Menglong Dong <menglong8.dong@...il.com>
To: peterz@...radead.org,
	jolsa@...nel.org
Cc: tglx@...utronix.de,
	mingo@...hat.com,
	bp@...en8.de,
	dave.hansen@...ux.intel.com,
	x86@...nel.org,
	hpa@...or.com,
	kees@...nel.org,
	samitolvanen@...gle.com,
	rppt@...nel.org,
	luto@...nel.org,
	mhiramat@...nel.org,
	ast@...nel.org,
	andrii@...nel.org,
	linux-kernel@...r.kernel.org,
	bpf@...r.kernel.org
Subject: [PATCH] x86/ibt: make is_endbr() notrace

is_endbr() is called in __ftrace_return_to_handler -> fprobe_return ->
kprobe_multi_link_exit_handler -> is_endbr.

It is not protected by the "bpf_prog_active", so it can't be traced by
kprobe-multi, which can cause recurring and panic the kernel. Fix it by
make it notrace.

Fixes: 72e213a7ccf9 ("x86/ibt: Clean up is_endbr()")
Signed-off-by: Menglong Dong <dongml2@...natelecom.cn>
---
 arch/x86/kernel/alternative.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 69fb818df2ee..f67a31c77c89 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -1108,7 +1108,7 @@ void __init_or_module noinline apply_returns(s32 *start, s32 *end) { }
 
 #ifdef CONFIG_X86_KERNEL_IBT
 
-__noendbr bool is_endbr(u32 *val)
+__noendbr notrace bool is_endbr(u32 *val)
 {
 	u32 endbr;
 
-- 
2.51.0