Merge branch 'sysctl-data-races'

Kuniyuki Iwashima says:

====================
sysctl: Fix data-races around ipv4_table.

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.

The first half of this series changes some proc handlers used in ipv4_table
to use READ_ONCE() and WRITE_ONCE() internally to fix data-races on the
sysctl side.  Then, the second half adds READ_ONCE() to the other readers
of ipv4_table.

Changes:
  v2:
    * Drop some changes that makes backporting difficult
      * First cleanup patch
      * Lockless helpers and .proc_handler changes
    * Drop the tracing part for .sysctl_mem
      * Steve already posted a fix
    * Drop int-to-bool change for cipso
      * Should be posted to net-next later
    * Drop proc_dobool() change
      * Can be included in another series

  v1: https://lore.kernel.org/netdev/20220706052130.16368-1-kuniyu@amazon.com/
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/net/sock.h b/include/net/sock.h
index 72ca97ccb460..9fa54762e077 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1529,7 +1529,7 @@ void __sk_mem_reclaim(struct sock *sk, int amount);
 /* sysctl_mem values are in pages, we convert them in SK_MEM_QUANTUM units */
 static inline long sk_prot_mem_limits(const struct sock *sk, int index)
 {
-	long val = sk->sk_prot->sysctl_mem[index];
+	long val = READ_ONCE(sk->sk_prot->sysctl_mem[index]);
 
 #if PAGE_SIZE > SK_MEM_QUANTUM
 	val <<= PAGE_SHIFT - SK_MEM_QUANTUM_SHIFT;