On Thu, Nov 1, 2018 at 7:41 AM, Masami Hiramatsu <[email protected]> wrote: > On Tue, 30 Oct 2018 13:40:27 -0400 > William Cohen <[email protected]> wrote: > >> On 10/22/18 5:30 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. >> > >> > Reported-by: William Cohen <[email protected]> >> > Fixes: 6974f0c4555e ("include/linux/string.h: add the option of fortified >> > string.h functions") >> > Cc: [email protected] >> > Signed-off-by: Kees Cook <[email protected]> >> > --- >> > 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. */ >> > >> >> The patch fixes the issue for kretprobes. It looks good to me. > > This looks good to me too. Thank you for finding and fixing it :) > > Acked-by: Masami Hiramatsu <[email protected]> > > Thanks!
Thanks for acks and testing. I've tossed this at the arm patch tracker: http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=8806/1 -- Kees Cook
