diff options
| author | Qais Yousef <qais.yousef@arm.com> | 2020-01-14 21:09:47 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-02-19 19:53:07 +0100 |
| commit | 9f6f61c61a84515d1533a0c71ab3159f39960236 (patch) | |
| tree | 610fddaead598295a2f31f6c4e99e2fa64099213 | |
| parent | 115402ee80cef6560be9d3456b4e61eab0afcf52 (diff) | |
sched/uclamp: Reject negative values in cpu_uclamp_write()
commit b562d140649966d4daedd0483a8fe59ad3bb465a upstream.
The check to ensure that the new written value into cpu.uclamp.{min,max}
is within range, [0:100], wasn't working because of the signed
comparison
7301 if (req.percent > UCLAMP_PERCENT_SCALE) {
7302 req.ret = -ERANGE;
7303 return req;
7304 }
# echo -1 > cpu.uclamp.min
# cat cpu.uclamp.min
42949671.96
Cast req.percent into u64 to force the comparison to be unsigned and
work as intended in capacity_from_percent().
# echo -1 > cpu.uclamp.min
sh: write error: Numerical result out of range
Fixes: 2480c093130f ("sched/uclamp: Extend CPU's cgroup controller")
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200114210947.14083-1-qais.yousef@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | kernel/sched/core.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 00743684a549..dfaefb175ba0 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7250,7 +7250,7 @@ capacity_from_percent(char *buf) &req.percent); if (req.ret) return req; - if (req.percent > UCLAMP_PERCENT_SCALE) { + if ((u64)req.percent > UCLAMP_PERCENT_SCALE) { req.ret = -ERANGE; return req; } |