From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: lizf@kernel.org To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Eryu Guan , Theodore Ts'o , Zefan Li Subject: [PATCH 3.4 096/146] ext4: check for zero length extent explicitly Date: Tue, 15 Sep 2015 17:03:31 +0800 Message-Id: <1442307861-32031-96-git-send-email-lizf@kernel.org> In-Reply-To: <1442307787-31952-1-git-send-email-lizf@kernel.org> References: <1442307787-31952-1-git-send-email-lizf@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: From: Eryu Guan 3.4.109-rc1 review patch. If anyone has any objections, please let me know. ------------------ commit 2f974865ffdfe7b9f46a9940836c8b167342563d upstream. The following commit introduced a bug when checking for zero length extent 5946d08 ext4: check for overlapping extents in ext4_valid_extent_entries() Zero length extent could pass the check if lblock is zero. Adding the explicit check for zero length back. Signed-off-by: Eryu Guan Signed-off-by: Theodore Ts'o Signed-off-by: Zefan Li --- fs/ext4/extents.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index bb72833..bbe09a9 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -320,7 +320,7 @@ static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext) ext4_lblk_t lblock = le32_to_cpu(ext->ee_block); ext4_lblk_t last = lblock + len - 1; - if (lblock > last) + if (len == 0 || lblock > last) return 0; return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len); } -- 1.9.1