linux-kernel - [PATCH] kprobe: use preempt_{disable, enable}_notrace in kprobe_busy

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]

Date:   Sat, 13 May 2023 17:05:48 +0800
From:   Ze Gao <zegao2021@...il.com>
To:     "Naveen N. Rao" <naveen.n.rao@...ux.ibm.com>,
        Anil S Keshavamurthy <anil.s.keshavamurthy@...el.com>,
        "David S. Miller" <davem@...emloft.net>,
        Masami Hiramatsu <mhiramat@...nel.org>
Cc:     Ze Gao <zegao@...cent.com>, linux-kernel@...r.kernel.org,
        linux-trace-kernel@...r.kernel.org
Subject: [PATCH] kprobe: use preempt_{disable, enable}_notrace in kprobe_busy_{begin, end}

Replacing preempt_{disable, enable} with its corresponding notrace
version in kprobe_busy_{begin, end} because they are called by
fprobe_kprobe_handler. Such changes would resolve the potential
stack recursion or overflow problem introduced by preempt_count
_{add, sub} when these functions themselves accidentally traced
by fprobe+rethook, and does not break the original semantics.

Signed-off-by: Ze Gao <zegao@...cent.com>
---
 kernel/kprobes.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 00e177de91cc..94d01b5d0646 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1242,7 +1242,7 @@ void kprobe_busy_begin(void)
 {
 	struct kprobe_ctlblk *kcb;
 
-	preempt_disable();
+	preempt_disable_notrace();
 	__this_cpu_write(current_kprobe, &kprobe_busy);
 	kcb = get_kprobe_ctlblk();
 	kcb->kprobe_status = KPROBE_HIT_ACTIVE;
@@ -1251,7 +1251,7 @@ void kprobe_busy_begin(void)
 void kprobe_busy_end(void)
 {
 	__this_cpu_write(current_kprobe, NULL);
-	preempt_enable();
+	preempt_enable_notrace();
 }
 
 /* Add the new probe to 'ap->list'. */
-- 
2.40.1