On Tue, Mar 11, 2014 at 2:59 AM, Matt Fleming <[email protected]> wrote: > On Mon, 10 Mar, at 10:41:57AM, Kees Cook wrote: >> > 4e14dfc7 Matt Fleming 2009-08-07 113 /* >> > 4e14dfc7 Matt Fleming 2009-08-07 114 * Print one address/symbol entries >> > per line. >> > 4e14dfc7 Matt Fleming 2009-08-07 115 */ >> > 4e14dfc7 Matt Fleming 2009-08-07 116 static void >> > print_trace_address(void *data, unsigned long addr, int reliable) >> > 4e14dfc7 Matt Fleming 2009-08-07 117 { >> > 4e14dfc7 Matt Fleming 2009-08-07 @118 printk(data); >> >> This needs to be "printk("%s", data);" so there is no chance of having >> "data" interpreted as a format string itself. > > OMG, I suck. Thanks for the report Kees. Have you got a patch for x86? > I think that's where this code came from.
Your patch looks great, thanks! -Kees > > Including Andrew, because I'm not sure who else is going to take this > patch. > > --- > > From 2284f3a27f68cec665aa982c0a226cf3fbf96ddf Mon Sep 17 00:00:00 2001 > From: Matt Fleming <[email protected]> > Date: Tue, 11 Mar 2014 09:50:26 +0000 > Subject: [PATCH] sh: Fix format string bug in stack tracer > > Kees reported the following error, > > arch/sh/kernel/dumpstack.c: In function 'print_trace_address': >>> arch/sh/kernel/dumpstack.c:118:2: error: format not a string literal and no >>> format arguments [-Werror=format-security] > > Use the "%s" format so that it's impossible to interpret 'data' as a > format string. > > Reported-by: Kees Cook <[email protected]> > Cc: Paul Mundt <[email protected]> > Cc: Andrew Morton <[email protected]> > Cc: [email protected] > Signed-off-by: Matt Fleming <[email protected]> > --- > arch/sh/kernel/dumpstack.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/sh/kernel/dumpstack.c b/arch/sh/kernel/dumpstack.c > index b959f5592604..8dfe645bcc4b 100644 > --- a/arch/sh/kernel/dumpstack.c > +++ b/arch/sh/kernel/dumpstack.c > @@ -115,7 +115,7 @@ static int print_trace_stack(void *data, char *name) > */ > static void print_trace_address(void *data, unsigned long addr, int reliable) > { > - printk(data); > + printk("%s", (char *)data); > printk_address(addr, reliable); > } > > -- > 1.8.5.3 > > -- > Matt Fleming, Intel Open Source Technology Center -- Kees Cook Chrome OS Security -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
