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authorKuniyuki Iwashima <kuniyu@amazon.com>2022-07-07 02:39:54 +0300
committerDavid S. Miller <davem@davemloft.net>2022-07-08 14:10:32 +0300
commitf613d86d014b6375a4085901de39406598121e35 (patch)
tree547c8ed1ab20103ae132cf5ace27714f12062e88 /kernel/sysctl.c
parent4762b532ec9539755aab61445d5da6e1926ccb99 (diff)
downloadlinux-f613d86d014b6375a4085901de39406598121e35.tar.xz
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: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'kernel/sysctl.c')
-rw-r--r--kernel/sysctl.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 2ab8c2a37e8f..4d87832367f2 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -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;