[PATCH] ARM: kprobes: Fix false positive with FORTIFY_SOURCE
From: Laura Abbott <hidden>
Date: 2018-10-22 10:30:24
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On 10/22/2018 02:30 AM, Kees Cook wrote:
The arm compiler internally interprets an inline assembly label as an unsigned long value, not a pointer. As a result, under CONFIG_FORTIFY_SOURCE, the size of the array pointed to by an address of a label is 4 bytes, which was tripping the runtime checks. Instead, we can just cast the label (as done with the size calculations earlier) to avoid the problem.
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1639397 Acked-by: Laura Abbott <redacted>
quoted hunk ↗ jump to hunk
Reported-by: William Cohen <redacted> Fixes: 6974f0c4555e ("include/linux/string.h: add the option of fortified string.h functions") Cc: stable at vger.kernel.org Signed-off-by: Kees Cook <redacted> --- 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 b2aa9b32bff2..2c118a6ab358 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, &optprobe_template_entry, + memcpy(code, (unsigned char *)optprobe_template_entry, TMPL_END_IDX * sizeof(kprobe_opcode_t)); /* Adjust buffer according to instruction. */