On Wed, 30 Oct 2024 10:32:08 -0300 Marc Dionne <marc.c.dionne@xxxxxxxxx> wrote:
> From: Marc Dionne <marc.dionne@xxxxxxxxxxxx>
>
> The number of slabs can easily exceed the hard coded MAX_SLABS in the
> slabinfo tool, causing it to overwrite memory and crash.
>
> Increase the value of MAX_SLABS, and check if that has been exceeded for
> each new slab, instead of at the end when it's already too late. Also
> move the check for MAX_ALIASES into the loop body.
>
> @@ -1240,6 +1240,8 @@ static void read_slab_dir(void)
> p--;
> alias->ref = strdup(p);
> alias++;
> + if (alias - aliasinfo == MAX_ALIASES)
> + fatal("Too many aliases\n");
Again, this is not correct. It has a potential off-by-one error.
If at this point, (alias - aliasinfo == MAX_ALIASES), we *do not know*
whether there are "Too many aliases". Because the parsing might have
reached the end of input, in which case we're fine.
A fix for this is to check for an invalid `alias' immediately before we
use it, as I described in the previous email.
