| Message ID | 148760167688.31154.15169118370965638805.stgit@bahia.lan |
|---|---|
| State | New |
| Headers | show |
On Mon, Feb 20, 2017 at 03:41:16PM +0100, Greg Kurz wrote: > The local_statfs() callback is vulnerable to symlink attacks because it > calls statfs() which follows symbolic links in all path elements. > > This patch converts local_statfs() to rely on open_nofollow() and fstatfs() > instead. > > This partly fixes CVE-2016-9602. > > Signed-off-by: Greg Kurz <groug@kaod.org> > --- > hw/9pfs/9p-local.c | 10 ++++------ > 1 file changed, 4 insertions(+), 6 deletions(-) Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c index 7f3d9dd9a499..ebc12f3c0691 100644 --- a/hw/9pfs/9p-local.c +++ b/hw/9pfs/9p-local.c @@ -1072,13 +1072,11 @@ static int local_fsync(FsContext *ctx, int fid_type, static int local_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf) { - char *buffer; - int ret; - char *path = fs_path->data; + int fd, ret; - buffer = rpath(s, path); - ret = statfs(buffer, stbuf); - g_free(buffer); + fd = local_open_nofollow(s, fs_path->data, O_RDONLY, 0); + ret = fstatfs(fd, stbuf); + close_preserve_errno(fd); return ret; }
The local_statfs() callback is vulnerable to symlink attacks because it calls statfs() which follows symbolic links in all path elements. This patch converts local_statfs() to rely on open_nofollow() and fstatfs() instead. This partly fixes CVE-2016-9602. Signed-off-by: Greg Kurz <groug@kaod.org> --- hw/9pfs/9p-local.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)