On Thu, 2018-10-04 at 15:28 -0700, Eric Biggers wrote:
> On Thu, Oct 04, 2018 at 06:21:35PM -0400, Mimi Zohar wrote:
> > On Wed, 2018-10-03 at 17:01 -0700, Eric Biggers wrote:
> > > From: Eric Biggers <ebiggers@xxxxxxxxxx>
> > >
> > > The 12 character temporary buffer is not necessarily long enough to hold
> > > a 'long' value. Increase it.
> > >
> > > Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
> > > ---
> > > security/integrity/ima/ima_fs.c | 7 ++++---
> > > 1 file changed, 4 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
> > > index ae9d5c766a3ce..4b50fe9c18edd 100644
> > > --- a/security/integrity/ima/ima_fs.c
> > > +++ b/security/integrity/ima/ima_fs.c
> > > @@ -42,14 +42,15 @@ static int __init default_canonical_fmt_setup(char *str)
> > > __setup("ima_canonical_fmt", default_canonical_fmt_setup);
> > >
> > > static int valid_policy = 1;
> > > -#define TMPBUFLEN 12
> > > +
> > > static ssize_t ima_show_htable_value(char __user *buf, size_t count,
> > > loff_t *ppos, atomic_long_t *val)
> > > {
> > > - char tmpbuf[TMPBUFLEN];
> > > + /* temporary buffer that is plenty long enough */
This comment is useless.
> > > + char tmpbuf[32];
char tmpbuf[32]; /* string size needed for largest long value */
> >
> > If the maximum value of long is 9,223,372,036,854,775,807, the largest
> > string needed to represent this value is 20 characters. Should 32 be
> > hardcoded like this?
>
> There's no real cost to overestimating slightly here, and it's better than
> trying to count exactly and getting it wrong (hint: it's actually more than 20
> characters).
Please explain how it is more than 20 characters.
Mimi
