Messages in this thread | | | Date | Thu, 4 Apr 2019 16:09:33 +0200 | From | Christian Brauner <> | Subject | Re: [PATCH] kernel/sysctl.c: fix out of bounds access in fs.file-max |
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On Wed, Apr 03, 2019 at 07:08:47PM +0200, Matteo Croce wrote: > On Wed, Apr 3, 2019 at 6:40 PM Matteo Croce <mcroce@redhat.com> wrote: > > > > On Wed, Apr 3, 2019 at 5:51 PM Matthew Wilcox <willy@infradead.org> wrote: > > > > > > On Wed, Apr 03, 2019 at 05:24:26PM +0200, Matteo Croce wrote: > > > > On Wed, Apr 3, 2019 at 4:02 PM Christian Brauner <christian@brauner.io> wrote: > > > > > Yeah, maybe but it still feels cleaner and more obvious to just add: > > > > > > > > > > static long long_zero; > > > > > > > > > > given that most callers actually seem to want an (unsigned) int. > > > > > > > > > > I don't have a strong opinion though so if others feel that it's just a > > > > > waste of space consider it acked. > > > > > > > > > > > > > Well, given that the value is zero, in this expectional case we could > > > > avoid duplicating the symbol and save 4 bytes. > > > > What the maintainers think? > > > > > > If we care about saving four bytes, we could just pass the address of > > > ZERO_PAGE(0). > > > > That would work, work too, maybe it's a bit overkill. > > int zero is always there and it's static, so enlarging it to long > > should be a straightforward fix. > > Obviously we can't do it for other numbers, but we can alias it just > > for the zero case.. > > > > Regards, > > > > -- > > Matteo Croce > > per aspera ad upstream > > Anyway, I'm fine with both solutions, as I have other patches in the
I think Matthew's idea gets us best of both worlds so I'd suggest to use it and resend the patch. You likely want to Cc stable@vger.kernel.org since the original patch this fixes got backported by Greg quite a bit since this was a rather long-standing issue. Please also Cc Andrew this time since he's likely going to pick it up.
Thanks for the patch! Christian
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