[PATCH v1 0/2] sysctl: cap file-max value at ULONG_MAX

[Christian Brauner]

Hey,

Here is v1 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. Let's detect the overflow and set to ULONG_MAX in
this case effectively capping the value.

The patch tries to ensure that there is no other user visible change in
behavior for other values. Only when a maximum value is set for a
specific sysctl will it be capped on overflow. The details are outlined
in the commit message of the first commit.

(This patchset is in reference to https://lkml.org/lkml/2018/10/11/585.)

Thanks!
Christian


Christian Brauner (2):
  sysctl: cap to ULONG_MAX in proc_get_long()
  sysctl: handle overflow for file-max

 kernel/sysctl.c | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

-- 
2.17.1