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| author | Kuniyuki Iwashima <kuniyu@amazon.com> | 2022-07-06 16:39:53 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2022-07-08 12:10:32 +0100 |
| commit | 4762b532ec9539755aab61445d5da6e1926ccb99 (patch) | |
| tree | 1e564c922409f15755da3ea6c1796e9e23451ce4 /kernel/sysctl.c | |
| parent | 1f1be04b4d48a2475ea1aab46a99221bfc5c0968 (diff) | |
| download | linux-4762b532ec9539755aab61445d5da6e1926ccb99.tar.gz linux-4762b532ec9539755aab61445d5da6e1926ccb99.tar.bz2 linux-4762b532ec9539755aab61445d5da6e1926ccb99.zip | |
sysctl: Fix data races in proc_douintvec().
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() to use READ_ONCE() and WRITE_ONCE()
internally to fix data-races on the sysctl side. For now, proc_douintvec()
itself is tolerant to a data-race, but we still need to add annotations on
the other subsystem's side.
Fixes: e7d316a02f68 ("sysctl: handle error writing UINT_MAX to u32 fields")
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.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/sysctl.c b/kernel/sysctl.c index c8a05655ae60..2ab8c2a37e8f 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -472,9 +472,9 @@ static int do_proc_douintvec_conv(unsigned long *lvalp, if (write) { if (*lvalp > UINT_MAX) return -EINVAL; - *valp = *lvalp; + WRITE_ONCE(*valp, *lvalp); } else { - unsigned int val = *valp; + unsigned int val = READ_ONCE(*valp); *lvalp = (unsigned long)val; } return 0; |