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
3 files changed
