sysctl: Fix data races in proc_douintvec_minmax().

A sysctl variable is accessed concurrently, and there is always a chance
of data-race.  So, all readers and writers need some basic protection to
avoid load/store-tearing.

This patch changes proc_douintvec_minmax() to use READ_ONCE() and
WRITE_ONCE() internally to fix data-races on the sysctl side.  For now,
proc_douintvec_minmax() itself is tolerant to a data-race, but we still
need to add annotations on the other subsystem's side.

Fixes: 61d9b56a89 ("sysctl: add unsigned int range support")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Kuniyuki Iwashima 2022-07-06 16:39:55 -07:00 committed by David S. Miller
parent f613d86d01
commit 2d3b559df3

View file

@ -923,7 +923,7 @@ static int do_proc_douintvec_minmax_conv(unsigned long *lvalp,
(param->max && *param->max < tmp)) (param->max && *param->max < tmp))
return -ERANGE; return -ERANGE;
*valp = tmp; WRITE_ONCE(*valp, tmp);
} }
return 0; return 0;