From: Mark Harris Date: Tue, 14 Jul 2026 00:30:56 +0000 (-0700) Subject: riscv: hwprobe: Avoid uninitialized read in hwprobe_get_cpus() X-Git-Tag: v7.2-rc4~1^2 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5caae1deee89a6582c761d5dcd4b924b744426cc;p=thirdparty%2Flinux.git riscv: hwprobe: Avoid uninitialized read in hwprobe_get_cpus() 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 Reviewed-by: Nam Cao Reviewed-by: Michael Ellerman Link: https://patch.msgid.link/20260714003056.73707-1-mark.hsj@gmail.com Signed-off-by: Paul Walmsley --- 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;