diff options
| author | Qais Yousef <qais.yousef@arm.com> | 2020-01-14 21:09:47 +0000 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2020-01-28 21:36:56 +0100 |
| commit | b562d140649966d4daedd0483a8fe59ad3bb465a (patch) | |
| tree | 51ebb6a78780b085099f205877f23c0b7a58911b /kernel/sched | |
| parent | b396f52326de20ec974471b7b19168867b365cbf (diff) | |
sched/uclamp: Reject negative values in cpu_uclamp_write()
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
Diffstat (limited to 'kernel/sched')
| -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 4ff03c27779e..55b9a9c53b91 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7264,7 +7264,7 @@ 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; } |