diff options
| author |   Willem de Bruijn <willemb@google.com> | 2021-12-15 09:39:37 -0500 |
|---|---|---|
| committer |   Jakub Kicinski <kuba@kernel.org> | 2021-12-15 17:49:36 -0800 |
| commit | ec6af094ea28f0f2dda1a6a33b14cd57e36a9755 (patch) | |
| tree | 907fc24cb8efc985e2475143b9e905bd6c99acd2 /net/packet/af_packet.c | |
| parent | netdevsim: Zero-initialize memory for new map's value in function nsim_bpf_map_alloc (diff) | |
| download | linux-dev-ec6af094ea28f0f2dda1a6a33b14cd57e36a9755.tar.xz linux-dev-ec6af094ea28f0f2dda1a6a33b14cd57e36a9755.zip | |
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/packet/af_packet.c')
| -rw-r--r-- | net/packet/af_packet.c | 5 |
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; } |