From 5e2c6fe7cc5314c13d96069328b603c40dc12b41 Mon Sep 17 00:00:00 2001 From: Greg Kurz Date: Fri, 16 Sep 2016 11:44:49 +0200 Subject: [PATCH] 9pfs: fix potential segfault during walk MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If the call to fid_to_qid() returns an error, we will call v9fs_path_free() on uninitialized paths. It is a regression introduced by the following commit: 56f101ecce0e 9pfs: handle walk of ".." in the root directory Let's fix this by initializing dpath and path before calling fid_to_qid(). Signed-off-by: Greg Kurz Reviewed-by: Cédric Le Goater [groug: updated the changelog to indicate this is regression and to provide the offending commit SHA1] Signed-off-by: Greg Kurz (cherry picked from commit 13fd08e631ec0c3ff5ad1bdcb6a4474c7d9a024f) Signed-off-by: Michael Roth --- hw/9pfs/9p.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c index 1ac05b24deb8..d47f5dee5248 100644 --- a/hw/9pfs/9p.c +++ b/hw/9pfs/9p.c @@ -1318,13 +1318,14 @@ static void v9fs_walk(void *opaque) goto out_nofid; } + v9fs_path_init(&dpath); + v9fs_path_init(&path); + err = fid_to_qid(pdu, fidp, &qid); if (err < 0) { goto out; } - v9fs_path_init(&dpath); - v9fs_path_init(&path); /* * Both dpath and path initially poin to fidp. * Needed to handle request with nwnames == 0