inetpeer: Fix data-races around sysctl.

[ Upstream commit 3d32edf1f3 ]

While reading inetpeer sysctl variables, they can be changed
concurrently.  So, we need to add READ_ONCE() to avoid data-races.

Fixes: 1da177e4c3 ("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>
This commit is contained in:
Kuniyuki Iwashima 2022-07-06 16:39:59 -07:00 committed by Greg Kroah-Hartman
parent a3d742c6b5
commit 20243034dc

View file

@ -147,16 +147,20 @@ static void inet_peer_gc(struct inet_peer_base *base,
struct inet_peer *gc_stack[],
unsigned int gc_cnt)
{
int peer_threshold, peer_maxttl, peer_minttl;
struct inet_peer *p;
__u32 delta, ttl;
int i;
if (base->total >= inet_peer_threshold)
peer_threshold = READ_ONCE(inet_peer_threshold);
peer_maxttl = READ_ONCE(inet_peer_maxttl);
peer_minttl = READ_ONCE(inet_peer_minttl);
if (base->total >= peer_threshold)
ttl = 0; /* be aggressive */
else
ttl = inet_peer_maxttl
- (inet_peer_maxttl - inet_peer_minttl) / HZ *
base->total / inet_peer_threshold * HZ;
ttl = peer_maxttl - (peer_maxttl - peer_minttl) / HZ *
base->total / peer_threshold * HZ;
for (i = 0; i < gc_cnt; i++) {
p = gc_stack[i];