On Mon, Oct 29, 2018 at 10:44 PM Kees Cook <keescook@xxxxxxxxxxxx> wrote: > > On Mon, Oct 29, 2018 at 7:58 AM, Christian Brauner <christian@xxxxxxxxxx> wrote: > > On Wed, Oct 17, 2018 at 12:33:20AM +0200, Christian Brauner wrote: > >> Hey, > >> > >> Here is v3 of this patchset. Changelogs are in the individual commits. > >> > >> Currently, when writing > >> > >> echo 18446744073709551616 > /proc/sys/fs/file-max > >> > >> /proc/sys/fs/file-max will overflow and be set to 0. That quickly > >> crashes the system. > >> > >> The first version of this patch intended to detect the overflow and cap > >> at ULONG_MAX. However, we should not do this and rather return EINVAL on > >> overflow. The reasons are: > >> - this aligns with other sysctl handlers that simply reject overflows > >> (cf. [1], [2], and a bunch of others) > >> - we already do a partial fail on overflow right now > >> Namely, when the TMPBUFLEN is exceeded. So we already reject values > >> such as 184467440737095516160 (21 chars) but accept values such as > >> 18446744073709551616 (20 chars) but both are overflows. So we should > >> just always reject 64bit overflows and not special-case this based on > >> the number of chars. > >> > >> (This patchset is in reference to https://lkml.org/lkml/2018/10/11/585.) > > > > Just so that we don't forget, can we make sure that this gets picked > > into linux-next? :) > > I was hoping akpm would take this? Andrew, does the v3 look okay to you? gentle ping again :) Christian
