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authorWillem de Bruijn <willemb@google.com>2021-12-15 09:39:37 -0500
committerJakub Kicinski <kuba@kernel.org>2021-12-15 17:49:36 -0800
commitec6af094ea28f0f2dda1a6a33b14cd57e36a9755 (patch)
tree907fc24cb8efc985e2475143b9e905bd6c99acd2 /net
parent481221775d53d6215a6e5e9ce1cce6d2b4ab9a46 (diff)
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>
Diffstat (limited to 'net')
-rw-r--r--net/packet/af_packet.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 46943a18a10d..76c2dca7f0a5 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -4492,9 +4492,10 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
}
out_free_pg_vec:
- bitmap_free(rx_owner_map);
- if (pg_vec)
+ if (pg_vec) {
+ bitmap_free(rx_owner_map);
free_pg_vec(pg_vec, order, req->tp_block_nr);
+ }
out:
return err;
}