From: Eric Dumazet edumazet@google.com
commit a9f5970767d11eadc805d5283f202612c7ba1f59 upstream.
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 Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv4/udp.c | 10 +++++----- net/ipv6/udp.c | 2 +- 2 files changed, 6 insertions(+), 6 deletions(-)
--- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -886,7 +886,7 @@ int udp_sendmsg(struct sock *sk, struct __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; @@ -1167,7 +1167,7 @@ int udp_sendpage(struct sock *sk, struct }
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; @@ -2034,9 +2034,9 @@ int udp_lib_setsockopt(struct sock *sk, 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); @@ -2143,7 +2143,7 @@ int udp_lib_getsockopt(struct sock *sk,
switch (optname) { case UDP_CORK: - val = up->corkflag; + val = READ_ONCE(up->corkflag); break;
case UDP_ENCAP: --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -1028,7 +1028,7 @@ int udpv6_sendmsg(struct sock *sk, struc struct ipcm6_cookie ipc6; int addr_len = msg->msg_namelen; 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 connected = 0; int is_udplite = IS_UDPLITE(sk);