From c5e3a41187ac01425f5ad1abce927905e4ac44e4 Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Thu, 1 Apr 2021 14:58:23 +0900 Subject: kernel: Initialize cpumask before parsing KMSAN complains that new_value at cpumask_parse_user() from write_irq_affinity() from irq_affinity_proc_write() is uninitialized. [ 148.133411][ T5509] ===================================================== [ 148.135383][ T5509] BUG: KMSAN: uninit-value in find_next_bit+0x325/0x340 [ 148.137819][ T5509] [ 148.138448][ T5509] Local variable ----new_value.i@irq_affinity_proc_write created at: [ 148.140768][ T5509] irq_affinity_proc_write+0xc3/0x3d0 [ 148.142298][ T5509] irq_affinity_proc_write+0xc3/0x3d0 [ 148.143823][ T5509] ===================================================== Since bitmap_parse() from cpumask_parse_user() calls find_next_bit(), any alloc_cpumask_var() + cpumask_parse_user() sequence has possibility that find_next_bit() accesses uninitialized cpu mask variable. Fix this problem by replacing alloc_cpumask_var() with zalloc_cpumask_var(). Signed-off-by: Tetsuo Handa Signed-off-by: Thomas Gleixner Acked-by: Steven Rostedt (VMware) Link: https://lore.kernel.org/r/20210401055823.3929-1-penguin-kernel@I-love.SAKURA.ne.jp --- kernel/profile.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/profile.c') diff --git a/kernel/profile.c b/kernel/profile.c index 6f69a4195d56..c2ebddb5e974 100644 --- a/kernel/profile.c +++ b/kernel/profile.c @@ -430,7 +430,7 @@ static ssize_t prof_cpu_mask_proc_write(struct file *file, cpumask_var_t new_value; int err; - if (!alloc_cpumask_var(&new_value, GFP_KERNEL)) + if (!zalloc_cpumask_var(&new_value, GFP_KERNEL)) return -ENOMEM; err = cpumask_parse_user(buffer, count, new_value); -- cgit v1.2.3-59-g8ed1b