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Commit 8d2daf56 authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by Greg Kroah-Hartman
Browse files

inetpeer: Fix data-races around sysctl. 



[ Upstream commit 3d32edf1f3c38d3301f6434e56316f293466d7fb ]

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

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 2968830c

net/ipv4/inetpeer.c

+8 −4
Original line number Diff line number Diff line
@@ -148,16 +148,20 @@ 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];