[PATCH net] net: udp: annotate data race around udp_sk(sk)->corkflag
From: Eric Dumazet <hidden>
Date: 2021-09-28 00:29:34
From: Eric Dumazet <edumazet@google.com>
up->corkflag field can be read or written without any lock.
Annotate accesses to avoid possible syzbot/KCSAN reports.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
net/ipv4/udp.c | 10 +++++-----
net/ipv6/udp.c | 2 +-
2 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 8851c9463b4b62c9017565f545250c4ffe22927c..2a7825a5b84254b70b2f06fc04d601719c2e0bc3 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c@@ -1053,7 +1053,7 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) __be16 dport; u8 tos; int err, is_udplite = IS_UDPLITE(sk); - int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; + int corkreq = READ_ONCE(up->corkflag) || msg->msg_flags&MSG_MORE; int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); struct sk_buff *skb; struct ip_options_data opt_copy;
@@ -1361,7 +1361,7 @@ int udp_sendpage(struct sock *sk, struct page *page, int offset, } up->len += size; - if (!(up->corkflag || (flags&MSG_MORE))) + if (!(READ_ONCE(up->corkflag) || (flags&MSG_MORE))) ret = udp_push_pending_frames(sk); if (!ret) ret = size;
@@ -2662,9 +2662,9 @@ int udp_lib_setsockopt(struct sock *sk, int level, int optname, switch (optname) { case UDP_CORK: if (val != 0) { - up->corkflag = 1; + WRITE_ONCE(up->corkflag, 1); } else { - up->corkflag = 0; + WRITE_ONCE(up->corkflag, 0); lock_sock(sk); push_pending_frames(sk); release_sock(sk);
@@ -2787,7 +2787,7 @@ int udp_lib_getsockopt(struct sock *sk, int level, int optname, switch (optname) { case UDP_CORK: - val = up->corkflag; + val = READ_ONCE(up->corkflag); break; case UDP_ENCAP:
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index ea53847b5b7e8b82f1898fa442327a9ce060085f..e505bb007e9f97995bf64a37702e0dc44a8c4a5c 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c@@ -1303,7 +1303,7 @@ int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) int addr_len = msg->msg_namelen; bool connected = false; int ulen = len; - int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; + int corkreq = READ_ONCE(up->corkflag) || msg->msg_flags&MSG_MORE; int err; int is_udplite = IS_UDPLITE(sk); int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);
--
2.33.0.685.g46640cef36-goog