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Christian Brauner authored
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. This commit sets the max and min value for file-max and returns -EINVAL when a long int is exceeded. Any higher value cannot currently be used as the percpu counters are long ints and not unsigned integers. This behavior also aligns with other tuneables that return -EINVAL when their range is exceeded. See e.g. [1], [2] and others. [1]: fb910c42 ("sysctl: check for UINT_MAX before unsigned int min/max") [2]: 196851be ("s390/topology: correct topology mode proc handler") Link: http://lkml.kernel.org/r/20190107222700.15954-3-christian@brauner.io Signed-off-by: Christian Brauner <christian@brauner.io> Acked-by: Kees Cook <keescook@chromium.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Joe Lawrence <joe.lawrence@redhat.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Waiman Long <longman@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
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