| Message ID | 20180907181905.GA15897@sigill.intra.peff.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | config.mak.dev: add -Wformat-security | expand |
On Fri, Sep 7, 2018 at 8:21 PM Jeff King <peff@peff.net> wrote: > > We currently build cleanly with -Wformat-security, and it's > a good idea to make sure we continue to do so (since calls > that trigger the warning may be security vulnerabilities). Nice. I had this flag in my config.mak too before switching to DEVELOPER=1. Didn't realize I lost the flag until now. > Signed-off-by: Jeff King <peff@peff.net> > --- > config.mak.dev | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/config.mak.dev b/config.mak.dev > index 9a998149d9..f832752454 100644 > --- a/config.mak.dev > +++ b/config.mak.dev > @@ -14,6 +14,7 @@ CFLAGS += -Wpointer-arith > CFLAGS += -Wstrict-prototypes > CFLAGS += -Wunused > CFLAGS += -Wvla > +CFLAGS += -Wformat-security Maybe keep it sorted
diff --git a/config.mak.dev b/config.mak.dev index 9a998149d9..f832752454 100644 --- a/config.mak.dev +++ b/config.mak.dev @@ -14,6 +14,7 @@ CFLAGS += -Wpointer-arith CFLAGS += -Wstrict-prototypes CFLAGS += -Wunused CFLAGS += -Wvla +CFLAGS += -Wformat-security ifndef COMPILER_FEATURES COMPILER_FEATURES := $(shell ./detect-compiler $(CC))
We currently build cleanly with -Wformat-security, and it's a good idea to make sure we continue to do so (since calls that trigger the warning may be security vulnerabilities). Note that we cannot use the stronger -Wformat-nonliteral, as there are case where we are clever with passing around pointers to string literals. E.g., bisect_rev_setup() takes bad_format and good_format parameters. These ultimately come from literals, but they still trigger the warning. Some of these might be fixable (e.g., by passing flags from which we locally select a format), and might even be worth fixing (not because of security, but just because it's an easy mistake to pass the wrong format). But there are other cases which are likely quite hard to fix (we actually generate formats in a local buffer in some cases). So let's punt on that for now and start with -Wformat-security, which is supposed to catch the most important cases. Signed-off-by: Jeff King <peff@peff.net> --- config.mak.dev | 1 + 1 file changed, 1 insertion(+)