[PATCH v2 net 09/12] net: Fix data-races around sysctl_mem.

From: Kuniyuki Iwashima
Date: Wed Jul 06 2022 - 19:43:13 EST


While reading .sysctl_mem, it can be changed concurrently.
So, we need to add READ_ONCE() to avoid data-races.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
---
include/net/sock.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

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;
--
2.30.2