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authorJ. Bruce Fields <bfields@redhat.com>2019-02-20 12:54:50 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-03-23 20:11:36 +0100
commitf03f5295caf0106820d1dac1fe0e019ee00f05dc (patch)
tree475f65c8c1ae8f0c1c4290a763d7caf899bde559 /net
parent1363f37fbd241c8341816513dfd07b3d9ed3a4ba (diff)
downloadtalos-obmc-linux-f03f5295caf0106820d1dac1fe0e019ee00f05dc.tar.gz
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svcrpc: fix UDP on servers with lots of threads
commit b7e5034cbecf5a65b7bfdc2b20a8378039577706 upstream. James Pearson found that an NFS server stopped responding to UDP requests if started with more than 1017 threads. sv_max_mesg is about 2^20, so that is probably where the calculation performed by svc_sock_setbufsize(svsk->sk_sock, (serv->sv_nrthreads+3) * serv->sv_max_mesg, (serv->sv_nrthreads+3) * serv->sv_max_mesg); starts to overflow an int. Reported-by: James Pearson <jcpearson@gmail.com> Tested-by: James Pearson <jcpearson@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
-rw-r--r--net/sunrpc/svcsock.c20
1 files changed, 10 insertions, 10 deletions
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index a6a060925e5d..43590a968b73 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -349,12 +349,16 @@ static ssize_t svc_recvfrom(struct svc_rqst *rqstp, struct kvec *iov,
/*
* Set socket snd and rcv buffer lengths
*/
-static void svc_sock_setbufsize(struct socket *sock, unsigned int snd,
- unsigned int rcv)
+static void svc_sock_setbufsize(struct svc_sock *svsk, unsigned int nreqs)
{
+ unsigned int max_mesg = svsk->sk_xprt.xpt_server->sv_max_mesg;
+ struct socket *sock = svsk->sk_sock;
+
+ nreqs = min(nreqs, INT_MAX / 2 / max_mesg);
+
lock_sock(sock->sk);
- sock->sk->sk_sndbuf = snd * 2;
- sock->sk->sk_rcvbuf = rcv * 2;
+ sock->sk->sk_sndbuf = nreqs * max_mesg * 2;
+ sock->sk->sk_rcvbuf = nreqs * max_mesg * 2;
sock->sk->sk_write_space(sock->sk);
release_sock(sock->sk);
}
@@ -516,9 +520,7 @@ static int svc_udp_recvfrom(struct svc_rqst *rqstp)
* provides an upper bound on the number of threads
* which will access the socket.
*/
- svc_sock_setbufsize(svsk->sk_sock,
- (serv->sv_nrthreads+3) * serv->sv_max_mesg,
- (serv->sv_nrthreads+3) * serv->sv_max_mesg);
+ svc_sock_setbufsize(svsk, serv->sv_nrthreads + 3);
clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
skb = NULL;
@@ -681,9 +683,7 @@ static void svc_udp_init(struct svc_sock *svsk, struct svc_serv *serv)
* receive and respond to one request.
* svc_udp_recvfrom will re-adjust if necessary
*/
- svc_sock_setbufsize(svsk->sk_sock,
- 3 * svsk->sk_xprt.xpt_server->sv_max_mesg,
- 3 * svsk->sk_xprt.xpt_server->sv_max_mesg);
+ svc_sock_setbufsize(svsk, 3);
/* data might have come in before data_ready set up */
set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
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