From: Adam Zabrocki <pi3@pi3.com.pl>
To: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>,
Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>,
"David S. Miller" <davem@davemloft.net>,
Masami Hiramatsu <mhiramat@kernel.org>,
linux-kernel@vger.kernel.org, Solar Designer <solar@openwall.com>
Subject: [PATCH] x86/kprobes: Fix KRETPROBES when CONFIG_KRETPROBE_ON_RETHOOK is set
Date: Fri, 15 Apr 2022 20:10:06 +0200 [thread overview]
Message-ID: <20220415181006.GA14021@pi3.com.pl> (raw)
In-Reply-To: <20220415180723.GA13921@pi3.com.pl>
[PATCH] x86/kprobes: Fix KRETPROBES when CONFIG_KRETPROBE_ON_RETHOOK is set
The recent kernel change "kprobes: Use rethook for kretprobe if possible",
introduced a potential NULL pointer dereference bug in the KRETPROBE
mechanism. The official Kprobes documentation defines that "Any or all
handlers can be NULL". Unfortunately, there is a missing return handler
verification to fulfill these requirements and can result in a NULL pointer
dereference bug.
This patch adds such verification in kretprobe_rethook_handler() function.
Fixes: 73f9b911faa7 ("kprobes: Use rethook for kretprobe if possible")
Signed-off-by: Adam Zabrocki <pi3@pi3.com.pl>
---
kernel/kprobes.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index dbe57df2e199..dd58c0be9ce2 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -2126,7 +2126,7 @@ static void kretprobe_rethook_handler(struct rethook_node *rh, void *data,
struct kprobe_ctlblk *kcb;
/* The data must NOT be null. This means rethook data structure is broken. */
- if (WARN_ON_ONCE(!data))
+ if (WARN_ON_ONCE(!data) || !rp->handler)
return;
__this_cpu_write(current_kprobe, &rp->kp);
--
pi3 (pi3ki31ny) - pi3 (at) itsec pl
http://pi3.com.pl
next prev parent reply other threads:[~2022-04-15 18:10 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-15 18:07 KRETPROBES are broken since the commit 73f9b911faa7 Adam Zabrocki
2022-04-15 18:10 ` Adam Zabrocki [this message]
2022-04-16 14:06 ` [PATCH] x86/kprobes: Fix KRETPROBES when CONFIG_KRETPROBE_ON_RETHOOK is set Masami Hiramatsu
2022-04-22 13:05 ` Masami Hiramatsu
2022-04-22 13:43 ` Steven Rostedt
2022-04-22 14:54 ` Masami Hiramatsu
2022-04-22 16:35 ` Adam Zabrocki
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