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| author | Kuniyuki Iwashima <kuniyu@amazon.com> | 2022-07-06 16:39:52 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-07-21 21:24:19 +0200 |
| commit | 279bf2a909e62124bf4a3b0faf735a5721e4c7f0 (patch) | |
| tree | 4930d3e6e8885859817f3f54562d89f172b941de /kernel | |
| parent | ad3014b0f6b28b9448543b1bdb57a0831dd4b818 (diff) | |
| download | linux-279bf2a909e62124bf4a3b0faf735a5721e4c7f0.tar.gz linux-279bf2a909e62124bf4a3b0faf735a5721e4c7f0.tar.bz2 linux-279bf2a909e62124bf4a3b0faf735a5721e4c7f0.zip | |
sysctl: Fix data races in proc_dointvec().
[ Upstream commit 1f1be04b4d48a2475ea1aab46a99221bfc5c0968 ]
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() to use READ_ONCE() and WRITE_ONCE()
internally to fix data-races on the sysctl side. For now, proc_dointvec()
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sysctl.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 0586047f7323..11f0714273ab 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -566,14 +566,14 @@ static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp, if (*negp) { if (*lvalp > (unsigned long) INT_MAX + 1) return -EINVAL; - *valp = -*lvalp; + WRITE_ONCE(*valp, -*lvalp); } else { if (*lvalp > (unsigned long) INT_MAX) return -EINVAL; - *valp = *lvalp; + WRITE_ONCE(*valp, *lvalp); } } else { - int val = *valp; + int val = READ_ONCE(*valp); if (val < 0) { *negp = true; *lvalp = -(unsigned long)val; |