From 0ac569bf6a7983c0c5747d6df8db9dc05bc92b6c Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Tue, 5 Feb 2019 16:37:40 +0100 Subject: [PATCH] ARM: 8834/1: Fix: kprobes: optimized kprobes illegal instruction commit e46daee53bb5 ("ARM: 8806/1: kprobes: Fix false positive with FORTIFY_SOURCE") introduced a regression in optimized kprobes. It triggers "invalid instruction" oopses when using kprobes instrumentation through lttng and perf. This commit was introduced in kernel v4.20, and has been backported to stable kernels 4.19 and 4.14. This crash was also reported by Hongzhi Song on the redhat bugzilla where the patch was originally introduced. Link: https://bugzilla.redhat.com/show_bug.cgi?id=1639397 Link: https://bugs.lttng.org/issues/1174 Link: https://lore.kernel.org/lkml/342740659.2887.1549307721609.JavaMail.zimbra@efficios.com Fixes: e46daee53bb5 ("ARM: 8806/1: kprobes: Fix false positive with FORTIFY_SOURCE") Signed-off-by: Mathieu Desnoyers Reported-by: Robert Berger Tested-by: Robert Berger Acked-by: Kees Cook Cc: Robert Berger Cc: Masami Hiramatsu Cc: William Cohen Cc: Laura Abbott Cc: Kees Cook Cc: # v4.14+ Cc: linux-arm-kernel@lists.infradead.org Cc: patches@armlinux.org.uk Signed-off-by: Russell King --- arch/arm/probes/kprobes/opt-arm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/probes/kprobes/opt-arm.c b/arch/arm/probes/kprobes/opt-arm.c index 2c118a6ab35873..0dc23fc227ed27 100644 --- a/arch/arm/probes/kprobes/opt-arm.c +++ b/arch/arm/probes/kprobes/opt-arm.c @@ -247,7 +247,7 @@ int arch_prepare_optimized_kprobe(struct optimized_kprobe *op, struct kprobe *or } /* Copy arch-dep-instance from template. */ - memcpy(code, (unsigned char *)optprobe_template_entry, + memcpy(code, (unsigned long *)&optprobe_template_entry, TMPL_END_IDX * sizeof(kprobe_opcode_t)); /* Adjust buffer according to instruction. */