[Qemu-stable] [PATCH 02/26] hw/9pfs: use O_NOFOLLOW for mapped readlink operation

[Michael Roth]

From: "Aneesh Kumar K.V" <address@hidden>

With mapped security models like mapped-xattr and mapped-file, we save the
symlink target as file contents. Now if we ever expose a normal directory
with mapped security model and find real symlinks in export path, never
follow them and return proper error.

Reviewed-by: Stefan Hajnoczi <address@hidden>
Signed-off-by: Aneesh Kumar K.V <address@hidden>
(cherry picked from commit aed858ce10ef09c7bdf03f73e75e772f567c74cd)

Signed-off-by: Michael Roth <address@hidden>
---
 hw/9pfs/virtio-9p-local.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/9pfs/virtio-9p-local.c b/hw/9pfs/virtio-9p-local.c
index 6ece6f7..87aa75d 100644
--- a/hw/9pfs/virtio-9p-local.c
+++ b/hw/9pfs/virtio-9p-local.c
@@ -284,7 +284,7 @@ static ssize_t local_readlink(FsContext *fs_ctx, V9fsPath 
*fs_path,
     if ((fs_ctx->export_flags & V9FS_SM_MAPPED) ||
         (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE)) {
         int fd;
-        fd = open(rpath(fs_ctx, path, buffer), O_RDONLY);
+        fd = open(rpath(fs_ctx, path, buffer), O_RDONLY | O_NOFOLLOW);
         if (fd == -1) {
             return -1;
         }
-- 
1.7.9.5