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net/packet: rx_owner_map depends on pg_vec

Hangbin Liu requested to merge liuhangbin/centos-stream-9:bz2050329 into main

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2050329 Upstream Status: net.git commit ec6af094ea28 CVE: CVE-2021-22600

commit ec6af094ea28f0f2dda1a6a33b14cd57e36a9755 Author: Willem de Bruijn willemb@google.com Date: Wed Dec 15 09:39:37 2021 -0500

net/packet: rx_owner_map depends on pg_vec

Packet sockets may switch ring versions. Avoid misinterpreting state
between versions, whose fields share a union. rx_owner_map is only
allocated with a packet ring (pg_vec) and both are swapped together.
If pg_vec is NULL, meaning no packet ring was allocated, then neither
was rx_owner_map. And the field may be old state from a tpacket_v3.

Fixes: 61fad6816fc1 ("net/packet: tpacket_rcv: avoid a producer race condition")
Reported-by: Syzbot <syzbot+1ac0994a0a0c55151121@syzkaller.appspotmail.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20211215143937.106178-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Signed-off-by: Hangbin Liu haliu@redhat.com

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