From 0f1db7dee200127da4c07928189748918c312031 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 4 Jul 2015 16:17:39 -0400 Subject: [PATCH] 9p: cope with bogus responses from server in p9_client_{read,write} if server claims to have written/read more than we'd told it to, warn and cap the claimed byte count to avoid advancing more than we are ready to. --- net/9p/client.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/net/9p/client.c b/net/9p/client.c index 81925b923318..498454b3c06c 100644 --- a/net/9p/client.c +++ b/net/9p/client.c @@ -1583,6 +1583,10 @@ p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err) p9_free_req(clnt, req); break; } + if (rsize < count) { + pr_err("bogus RREAD count (%d > %d)\n", count, rsize); + count = rsize; + } p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count); if (!count) { @@ -1650,6 +1654,10 @@ p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err) p9_free_req(clnt, req); break; } + if (rsize < count) { + pr_err("bogus RWRITE count (%d > %d)\n", count, rsize); + count = rsize; + } p9_debug(P9_DEBUG_9P, "<<< RWRITE count %d\n", count);