[PATCH net] inet: control sockets should not use current thread task_frag

From: Eric Dumazet <edumazet@google.com>
To: "David S . Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com,
	Eric Dumazet <edumazet@google.com>,
	syzbot+bebc6f1acdf4cbb79b03@syzkaller.appspotmail.com,
	Guillaume Nault <gnault@redhat.com>,
	Benjamin Coddington <bcodding@redhat.com>
Subject: [PATCH net] inet: control sockets should not use current thread task_frag
Date: Tue,  3 Jan 2023 19:27:36 +0000	[thread overview]
Message-ID: <20230103192736.454149-1-edumazet@google.com> (raw)

Because ICMP handlers run from softirq contexts,
they must not use current thread task_frag.

Previously, all sockets allocated by inet_ctl_sock_create()
would use the per-socket page fragment, with no chance of
recursion.

Fixes: 98123866fcf3 ("Treewide: Stop corrupting socket's task_frag")
Reported-by: syzbot+bebc6f1acdf4cbb79b03@syzkaller.appspotmail.com
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Guillaume Nault <gnault@redhat.com>
Cc: Benjamin Coddington <bcodding@redhat.com>
---
 net/ipv4/af_inet.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index ab4a06be489b5d410cec603bf56248d31dbc90dd..6c0ec27899431eb56e2f9d0c3a936b77f44ccaca 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1665,6 +1665,7 @@ int inet_ctl_sock_create(struct sock **sk, unsigned short family,
 	if (rc == 0) {
 		*sk = sock->sk;
 		(*sk)->sk_allocation = GFP_ATOMIC;
+		(*sk)->sk_use_task_frag = false;
 		/*
 		 * Unhash it so that IP input processing does not even see it,
 		 * we do not wish this socket to see incoming packets.
-- 
2.39.0.314.g84b9a713c41-goog

