From 882af43a0fc37e26d85fb0df0c9edd3bed928de4 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 12 Sep 2023 09:17:30 +0000 Subject: udplite: fix various data-races udp->pcflag, udp->pcslen and udp->pcrlen reads/writes are racy. Move udp->pcflag to udp->udp_flags for atomicity, and add READ_ONCE()/WRITE_ONCE() annotations for pcslen and pcrlen. Fixes: ba4e58eca8aa ("[NET]: Supporting UDP-Lite (RFC 3828) in Linux") Signed-off-by: Eric Dumazet Reviewed-by: Willem de Bruijn Signed-off-by: Paolo Abeni --- include/linux/udp.h | 6 ++---- include/net/udplite.h | 14 +++++++++----- 2 files changed, 11 insertions(+), 9 deletions(-) (limited to 'include') diff --git a/include/linux/udp.h b/include/linux/udp.h index 58156edec009..d04188714dca 100644 --- a/include/linux/udp.h +++ b/include/linux/udp.h @@ -40,6 +40,8 @@ enum { UDP_FLAGS_ACCEPT_FRAGLIST, UDP_FLAGS_ACCEPT_L4, UDP_FLAGS_ENCAP_ENABLED, /* This socket enabled encap */ + UDP_FLAGS_UDPLITE_SEND_CC, /* set via udplite setsockopt */ + UDP_FLAGS_UDPLITE_RECV_CC, /* set via udplite setsockopt */ }; struct udp_sock { @@ -54,10 +56,6 @@ struct udp_sock { int pending; /* Any pending frames ? */ __u8 encap_type; /* Is this an Encapsulation socket? */ -/* indicator bits used by pcflag: */ -#define UDPLITE_SEND_CC 0x1 /* set via udplite setsockopt */ -#define UDPLITE_RECV_CC 0x2 /* set via udplite setsocktopt */ - __u8 pcflag; /* marks socket as UDP-Lite if > 0 */ /* * Following member retains the information to create a UDP header * when the socket is uncorked. diff --git a/include/net/udplite.h b/include/net/udplite.h index bd33ff2b8f42..786919d29f8d 100644 --- a/include/net/udplite.h +++ b/include/net/udplite.h @@ -66,14 +66,18 @@ static inline int udplite_checksum_init(struct sk_buff *skb, struct udphdr *uh) /* Fast-path computation of checksum. Socket may not be locked. */ static inline __wsum udplite_csum(struct sk_buff *skb) { - const struct udp_sock *up = udp_sk(skb->sk); const int off = skb_transport_offset(skb); + const struct sock *sk = skb->sk; int len = skb->len - off; - if ((up->pcflag & UDPLITE_SEND_CC) && up->pcslen < len) { - if (0 < up->pcslen) - len = up->pcslen; - udp_hdr(skb)->len = htons(up->pcslen); + if (udp_test_bit(UDPLITE_SEND_CC, sk)) { + u16 pcslen = READ_ONCE(udp_sk(sk)->pcslen); + + if (pcslen < len) { + if (pcslen > 0) + len = pcslen; + udp_hdr(skb)->len = htons(pcslen); + } } skb->ip_summed = CHECKSUM_NONE; /* no HW support for checksumming */ -- cgit v1.2.3