Commit 7cb09575 authored by Neil Brown's avatar Neil Brown Committed by Linus Torvalds

[PATCH] kNFSd: Fix race in svcsock.c

From: Trond Myklebust <trond.myklebust@fys.uio.no>


knfsd needs to disable soft interrupts when calling
csum_partial_copy_to_xdr().

At the moment there's a nasty conflict between the RPC server and
client. The problem arises when you get to xdr_partial_copy_from_skb()
(and the kmap_atomic()); the RPC client can end up calling the same
function from a ->data_ready() soft interrupt, and corrupt any data
the knfsd process may have copied.
parent 453a629b
......@@ -577,12 +577,15 @@ svc_udp_recvfrom(struct svc_rqst *rqstp)
if (skb_is_nonlinear(skb)) {
/* we have to copy */
local_bh_disable();
if (csum_partial_copy_to_xdr(&rqstp->rq_arg, skb)) {
local_bh_enable();
/* checksum error */
skb_free_datagram(svsk->sk_sk, skb);
svc_sock_received(svsk);
return 0;
}
local_bh_enable();
skb_free_datagram(svsk->sk_sk, skb);
} else {
/* we can use it in-place */
......
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