Hi Andrew, Can you take this patch for -mm? -Kees On Sun, Dec 9, 2018 at 8:41 AM Christian Brauner <christian.brauner@xxxxxxxxxxxxx> wrote: > > 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 -- Kees Cook
