From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+376cea2b0ef340db3dd4@syzkaller.appspotmail.com, Amir Goldstein , Miklos Szeredi Subject: [PATCH 4.14 79/94] ovl: fix access beyond unterminated strings Date: Mon, 8 Oct 2018 20:32:00 +0200 Message-Id: <20181008175610.286599259@linuxfoundation.org> In-Reply-To: <20181008175605.067676667@linuxfoundation.org> References: <20181008175605.067676667@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Amir Goldstein commit 601350ff58d5415a001769532f6b8333820e5786 upstream. KASAN detected slab-out-of-bounds access in printk from overlayfs, because string format used %*s instead of %.*s. > BUG: KASAN: slab-out-of-bounds in string+0x298/0x2d0 lib/vsprintf.c:604 > Read of size 1 at addr ffff8801c36c66ba by task syz-executor2/27811 > > CPU: 0 PID: 27811 Comm: syz-executor2 Not tainted 4.19.0-rc5+ #36 ... > printk+0xa7/0xcf kernel/printk/printk.c:1996 > ovl_lookup_index.cold.15+0xe8/0x1f8 fs/overlayfs/namei.c:689 Reported-by: syzbot+376cea2b0ef340db3dd4@syzkaller.appspotmail.com Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi Fixes: 359f392ca53e ("ovl: lookup index entry for copy up origin") Cc: # v4.13 Signed-off-by: Greg Kroah-Hartman --- fs/overlayfs/namei.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/overlayfs/namei.c +++ b/fs/overlayfs/namei.c @@ -519,7 +519,7 @@ static struct dentry *ovl_lookup_index(s index = NULL; goto out; } - pr_warn_ratelimited("overlayfs: failed inode index lookup (ino=%lu, key=%*s, err=%i);\n" + pr_warn_ratelimited("overlayfs: failed inode index lookup (ino=%lu, key=%.*s, err=%i);\n" "overlayfs: mount with '-o index=off' to disable inodes index.\n", d_inode(origin)->i_ino, name.len, name.name, err);