From: Al Viro <viro@zeniv.linux.org.uk>
Date: Fri, 14 Apr 2017 21:22:18 +0000 (-0400)
Subject: p9_client_readdir() fix
X-Git-Tag: v3.12.74~4
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a8ece68c56153be505ef9b3ef55e4bcd3cef9331;p=thirdparty%2Fkernel%2Fstable.git

p9_client_readdir() fix

commit 71d6ad08379304128e4bdfaf0b4185d54375423e upstream.

Don't assume that server is sane and won't return more data than
asked for.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---

diff --git a/net/9p/client.c b/net/9p/client.c
index ae4778c84559f..bde453ae5e2e5 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -2099,6 +2099,10 @@ int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
 		trace_9p_protocol_dump(clnt, req->rc);
 		goto free_and_error;
 	}
+	if (rsize < count) {
+		pr_err("bogus RREADDIR count (%d > %d)\n", count, rsize);
+		count = rsize;
+	}
 
 	p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);