Commit f01bedbd authored by Tetsuo Handa's avatar Tetsuo Handa Committed by Jialin Zhang
Browse files

kernel: Initialize cpumask before parsing 

mainline inclusion
from mainline-v5.13-rc1
commit c5e3a411
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6O293

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c5e3a41187ac01425f5ad1abce927905e4ac44e4



--------------------------------

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: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20210401055823.3929-1-penguin-kernel@I-love.SAKURA.ne.jp


Signed-off-by: default avatarLin Yujun <linyujun809@huawei.com>
Reviewed-by: default avatarZhang Jianhua <chris.zjh@huawei.com>
Signed-off-by: default avatarJialin Zhang <zhangjialin11@huawei.com>
parent 24ead127

kernel/irq/proc.c

+2 −2
Original line number Diff line number Diff line
@@ -144,7 +144,7 @@ static ssize_t write_irq_affinity(int type, struct file *file, 
	if (!irq_can_set_affinity_usr(irq) || no_irq_affinity)

		return -EIO;



	if (!alloc_cpumask_var(&new_value, GFP_KERNEL))

	if (!zalloc_cpumask_var(&new_value, GFP_KERNEL))

		return -ENOMEM;



	if (type)
@@ -238,7 +238,7 @@ static ssize_t default_affinity_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);

kernel/profile.c

+1 −1
Original line number Diff line number Diff line
@@ -438,7 +438,7 @@ 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);

kernel/trace/trace.c

+1 −1
Original line number Diff line number Diff line
@@ -4792,7 +4792,7 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf, 
	cpumask_var_t tracing_cpumask_new;

	int err;



	if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL))

	if (!zalloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL))

		return -ENOMEM;



	err = cpumask_parse_user(ubuf, count, tracing_cpumask_new);