From: Eric Dumazet edumazet@google.com
[ Upstream commit fd53c297aa7b077ae98a3d3d2d3aa278a1686ba6 ]
po->auxdata can be read while another thread is changing its value, potentially raising KCSAN splat.
Convert it to PACKET_SOCK_AUXDATA flag.
Fixes: 8dc419447415 ("[PACKET]: Add optional checksum computation for recvmsg") Signed-off-by: Eric Dumazet edumazet@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/packet/af_packet.c | 8 +++----- net/packet/diag.c | 2 +- net/packet/internal.h | 4 ++-- 3 files changed, 6 insertions(+), 8 deletions(-)
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 0e88a8dd4530f..13666fe787db7 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -3456,7 +3456,7 @@ static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, copy_len); }
- if (pkt_sk(sk)->auxdata) { + if (packet_sock_flag(pkt_sk(sk), PACKET_SOCK_AUXDATA)) { struct tpacket_auxdata aux;
aux.tp_status = TP_STATUS_USER; @@ -3839,9 +3839,7 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv if (copy_from_user(&val, optval, sizeof(val))) return -EFAULT;
- lock_sock(sk); - po->auxdata = !!val; - release_sock(sk); + packet_sock_flag_set(po, PACKET_SOCK_AUXDATA, val); return 0; } case PACKET_ORIGDEV: @@ -4002,7 +4000,7 @@ static int packet_getsockopt(struct socket *sock, int level, int optname,
break; case PACKET_AUXDATA: - val = po->auxdata; + val = packet_sock_flag(po, PACKET_SOCK_AUXDATA); break; case PACKET_ORIGDEV: val = packet_sock_flag(po, PACKET_SOCK_ORIGDEV); diff --git a/net/packet/diag.c b/net/packet/diag.c index e1ac9bb375b31..d704c7bf51b20 100644 --- a/net/packet/diag.c +++ b/net/packet/diag.c @@ -23,7 +23,7 @@ static int pdiag_put_info(const struct packet_sock *po, struct sk_buff *nlskb) pinfo.pdi_flags = 0; if (po->running) pinfo.pdi_flags |= PDI_RUNNING; - if (po->auxdata) + if (packet_sock_flag(po, PACKET_SOCK_AUXDATA)) pinfo.pdi_flags |= PDI_AUXDATA; if (packet_sock_flag(po, PACKET_SOCK_ORIGDEV)) pinfo.pdi_flags |= PDI_ORIGDEV; diff --git a/net/packet/internal.h b/net/packet/internal.h index 23649010e9586..2b2b85dadf8ea 100644 --- a/net/packet/internal.h +++ b/net/packet/internal.h @@ -117,8 +117,7 @@ struct packet_sock { struct mutex pg_vec_lock; unsigned long flags; unsigned int running; /* bind_lock must be held */ - unsigned int auxdata:1, /* writer must hold sock lock */ - has_vnet_hdr:1, + unsigned int has_vnet_hdr:1, /* writer must hold sock lock */ tp_loss:1, tp_tx_has_off:1; int pressure; @@ -145,6 +144,7 @@ static struct packet_sock *pkt_sk(struct sock *sk)
enum packet_sock_flags { PACKET_SOCK_ORIGDEV, + PACKET_SOCK_AUXDATA, };
static inline void packet_sock_flag_set(struct packet_sock *po,