When cpusetsize < cpumask_size(), hwprobe_get_cpus() did not fully
initialize its copy of the cpu mask, which could cause non-deterministic
results from the riscv_hwprobe syscall on a system with more than 8 CPUs
when the supplied cpu mask is empty. Address this by fully initializing
the cpu mask.
Fixes: e178bf146e4b ("RISC-V: hwprobe: Introduce which-cpus flag")
Signed-off-by: Mark Harris <mark.hsj@gmail.com>
Reviewed-by: Nam Cao <namcao@linutronix.de>
Reviewed-by: Michael Ellerman <mpe@kernel.org>
---
v2: Add Fixes: and Reviewed-by: tags
arch/riscv/kernel/sys_hwprobe.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/riscv/kernel/sys_hwprobe.c b/arch/riscv/kernel/sys_hwprobe.c
index 1659d31fd288..caf6762427c8 100644
--- a/arch/riscv/kernel/sys_hwprobe.c
+++ b/arch/riscv/kernel/sys_hwprobe.c
@@ -450,6 +450,7 @@ static int hwprobe_get_cpus(struct riscv_hwprobe __user *pairs,
if (cpusetsize > cpumask_size())
cpusetsize = cpumask_size();
+ cpumask_clear(&cpus);
ret = copy_from_user(&cpus, cpus_user, cpusetsize);
if (ret)
return -EFAULT;
--
2.55.0