d2fc4134aa
commit 079be8fc630943d9fc70a97807feb73d169ee3fc upstream. The validation of the value written to sched_rt_period_us was broken because: - the sysclt_sched_rt_period is declared as unsigned int - parsed by proc_do_intvec() - the range is asserted after the value parsed by proc_do_intvec() Because of this negative values written to the file were written into a unsigned integer that were later on interpreted as large positive integers which did passed the check: if (sysclt_sched_rt_period <= 0) return EINVAL; This commit fixes the parsing by setting explicit range for both perid_us and runtime_us into the sched_rt_sysctls table and processes the values with proc_dointvec_minmax() instead. Alternatively if we wanted to use full range of unsigned int for the period value we would have to split the proc_handler and use proc_douintvec() for it however even the Documentation/scheduller/sched-rt-group.rst describes the range as 1 to INT_MAX. As far as I can tell the only problem this causes is that the sysctl file allows writing negative values which when read back may confuse userspace. There is also a LTP test being submitted for these sysctl files at: http://patchwork.ozlabs.org/project/ltp/patch/20230901144433.2526-1-chrubis@suse.cz/ Signed-off-by: Cyril Hrubis <chrubis@suse.cz> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20231002115553.3007-2-chrubis@suse.cz [ pvorel: rebased for 5.4 ] Reviewed-by: Petr Vorel <pvorel@suse.cz> Signed-off-by: Petr Vorel <pvorel@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.