From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> To: Kees Cook <keescook@chromium.org> Cc: William Cohen <wcohen@redhat.com>, stable@vger.kernel.org, Laura Abbott <labbott@redhat.com>, Masami Hiramatsu <mhiramat@kernel.org>, Russell King <rmk+kernel@armlinux.org.uk>, linux-kernel <linux-kernel@vger.kernel.org>, lttng@reliableembeddedsystems.com, lttng-dev <lttng-dev@lists.lttng.org> Subject: BUG: optimized kprobes illegal instructions in v4.19 stable kernels Date: Mon, 4 Feb 2019 14:15:21 -0500 (EST) [thread overview] Message-ID: <342740659.2887.1549307721609.JavaMail.zimbra@efficios.com> (raw) Hi, I notice this commit as a possible culprit of the illegal instructions my lttng users are noticing on arm32 when using kprobes on a v4.19.13 Linux kernel in a Yocto environment [1]. They were able to reproduce the issue with perf as well. commit e46daee53bb50bde38805f1823a182979724c229 Author: Kees Cook <keescook@chromium.org> Date: Tue Oct 30 22:12:56 2018 +0100 ARM: 8806/1: kprobes: Fix false positive with FORTIFY_SOURCE I *think* the intent there was to do - memcpy(code, &optprobe_template_entry, + memcpy(code, (unsigned long *)&optprobe_template_entry, But if you look at the commit, the "&" seems to have been stripped away, which happens to change the behavior significantly. Has this change ever been runtime-tested ? It has been backported to: - 4.19 stable as commit 3fe0c68aea21 - 4.14 stable as commit f9e0bc710347 Thanks, Mathieu [1] https://bugs.lttng.org/issues/1174 -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com
next reply other threads:[~2019-02-04 19:15 UTC|newest] Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-02-04 19:15 Mathieu Desnoyers [this message] 2019-02-05 15:06 ` Kees Cook 2019-02-06 4:41 ` Masami Hiramatsu 2019-02-18 12:26 ` Greg KH 2019-02-18 14:11 ` Masami Hiramatsu 2019-02-18 14:55 ` Mathieu Desnoyers 2019-02-21 20:02 ` Mathieu Desnoyers 2019-02-22 0:10 ` Russell King - ARM Linux admin 2019-02-22 0:17 ` Mathieu Desnoyers 2019-02-22 6:25 ` Greg Kroah-Hartman 2019-02-22 8:29 ` Greg Kroah-Hartman 2019-02-22 20:18 ` Mathieu Desnoyers 2019-02-06 11:48 ` David Laight
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