tree 472de6aedac39abbc952a2ac967da9a9d37c88fd
parent f99027ab63bee0cbbde549ff663aef8b1c1944b5
author Miklos Szeredi <mszeredi@redhat.com> 1547630879 +0100
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1549997244 +0100

fuse: handle zero sized retrieve correctly

commit 97e1532ef81acb31c30f9e75bf00306c33a77812 upstream.

Dereferencing req->page_descs[0] will Oops if req->max_pages is zero.

Reported-by: syzbot+c1e36d30ee3416289cc0@syzkaller.appspotmail.com
Tested-by: syzbot+c1e36d30ee3416289cc0@syzkaller.appspotmail.com
Fixes: b2430d7567a3 ("fuse: add per-page descriptor <offset, length> to fuse_req")
Cc: <stable@vger.kernel.org> # v3.9
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>