diff options
| author | Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> | 2021-04-01 14:58:23 +0900 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2021-04-10 13:35:54 +0200 |
| commit | c5e3a41187ac01425f5ad1abce927905e4ac44e4 (patch) | |
| tree | 554e8ce75c450c4933f1482f8ec29806adc1307d /kernel/trace | |
| parent | 883ccef355b910398b99dfaf96d40557479a7e9b (diff) | |
| download | lwn-c5e3a41187ac01425f5ad1abce927905e4ac44e4.tar.gz lwn-c5e3a41187ac01425f5ad1abce927905e4ac44e4.zip | |
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 <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20210401055823.3929-1-penguin-kernel@I-love.SAKURA.ne.jp
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/trace.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index eccb4e1187cc..7607dc8a20b2 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4827,7 +4827,7 @@ 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); |