Commit f613d86d authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by David S. Miller
Browse files

sysctl: Fix data races in proc_dointvec_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_dointvec_minmax() to use READ_ONCE() and
WRITE_ONCE() internally to fix data-races on the sysctl side.  For now,
proc_dointvec_minmax() itself is tolerant to a data-race, but we still
need to add annotations on the other subsystem's side.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4762b532

kernel/sysctl.c

+1 −1
Original line number Diff line number Diff line
@@ -857,7 +857,7 @@ static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp, 
		if ((param->min && *param->min > tmp) ||

		    (param->max && *param->max < tmp))

			return -EINVAL;

		*valp = tmp;

		WRITE_ONCE(*valp, tmp);

	}



	return 0;