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, Kees Cook , Silvio Cesare , Richard Weinberger Subject: [PATCH 4.9 51/63] ubifs: Check data node size before truncate Date: Fri, 7 Sep 2018 23:10:22 +0200 Message-Id: <20180907211015.785112491@linuxfoundation.org> In-Reply-To: <20180907211012.965501324@linuxfoundation.org> References: <20180907211012.965501324@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Richard Weinberger commit 95a22d2084d72ea067d8323cc85677dba5d97cae upstream. Check whether the size is within bounds before using it. If the size is not correct, abort and dump the bad data node. Cc: Kees Cook Cc: Silvio Cesare Cc: stable@vger.kernel.org Fixes: 1e51764a3c2ac ("UBIFS: add new flash file system") Reported-by: Silvio Cesare Signed-off-by: Richard Weinberger Reviewed-by: Kees Cook Signed-off-by: Richard Weinberger Signed-off-by: Greg Kroah-Hartman --- fs/ubifs/journal.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) --- a/fs/ubifs/journal.c +++ b/fs/ubifs/journal.c @@ -1344,7 +1344,16 @@ int ubifs_jnl_truncate(struct ubifs_info else if (err) goto out_free; else { - if (le32_to_cpu(dn->size) <= dlen) + int dn_len = le32_to_cpu(dn->size); + + if (dn_len <= 0 || dn_len > UBIFS_BLOCK_SIZE) { + ubifs_err(c, "bad data node (block %u, inode %lu)", + blk, inode->i_ino); + ubifs_dump_node(c, dn); + goto out_free; + } + + if (dn_len <= dlen) dlen = 0; /* Nothing to do */ else { int compr_type = le16_to_cpu(dn->compr_type);