From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZrBCroOsDTWQjjFsYP60khlN+w5EHIE+VGLn0HJNUa/iCgFzjVEqbCf3sZRU9daNhkWQa2O ARC-Seal: i=1; a=rsa-sha256; t=1526280886; cv=none; d=google.com; s=arc-20160816; b=ShEaxYZEeDoQOzHRuuIw5W8KfKRQ4W00Zb2Uwk9p/JV/nlsJamZ7qdQa/DPTCvJ5We Y68InsyAS6cXVzCVD8gAMlSAJn4VA7OUewjhsSeWLXsqn9ZZjOZ7hbIwzIQ+vwq3Bwsl Fmnc4z4Z5jil8fUkNoyQbM5nRZHH7bMRFIuhFPpT5dvvyYiY5Nsxnq5/HeEPI6IwjEQg 0sw2TQsR91JKYC4BdX50MhUPH6o+TSh74+UtQoRTj8l1K9gU46rID8A399DyPLVZGS8p PWIKzyQQz1uo2ls4xhIqRHX8Dq5GI/xUoGI3PldVE6A/qwEXCa9e6M9/KLyKONPOTEO7 NW7g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:dkim-signature:arc-authentication-results; bh=2rcgYRJj3e/rbwPQtJTUl/XMYV/LOvWMC5aty3oH9tU=; b=AzMhvxT7aHpePvjps6XUhQBFHTnAnfo0j+0LE8cPfNLKbebRlXT56CZCuByJqI++u6 KK9wlPzScPw0D73obOeD5Dg7dmMVsFY3gFrUlJNXZRKUeI7hgrk1uqQXhAKeBRrTq93q cHhIwLrUT0XkBrXUCkV7cxMyM5+nC5zbrBhLJ0NaxSPZwM7gUx4uUJXpMNVf1JvrqItC Owq2It29hukoUyJnua66zMyi7zuvBt+0vUq6CLRl2DTEd8Ufz63eziBdobbP/KbRkWDy +yZCCf1azLvkSRGbKbapB7gggQtkFWkg8328ToT2ECK0clam3R0AQp/k/8MsBImAwocN VMuw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=f3hdSNP3; spf=pass (google.com: domain of srs0=ywzk=ib=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=ywzk=IB=linuxfoundation.org=gregkh@kernel.org Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=f3hdSNP3; spf=pass (google.com: domain of srs0=ywzk=ib=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=ywzk=IB=linuxfoundation.org=gregkh@kernel.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Wei Fang , Chao Yu , Jaegeuk Kim , Guenter Roeck Subject: [PATCH 4.9 15/36] f2fs: fix a dead loop in f2fs_fiemap() Date: Mon, 14 May 2018 08:48:49 +0200 Message-Id: <20180514064805.465108725@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180514064804.252823817@linuxfoundation.org> References: <20180514064804.252823817@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1600421360895982780?= X-GMAIL-MSGID: =?utf-8?q?1600421507104178818?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Wei Fang commit b86e33075ed1909d8002745b56ecf73b833db143 upstream. A dead loop can be triggered in f2fs_fiemap() using the test case as below: ... fd = open(); fallocate(fd, 0, 0, 4294967296); ioctl(fd, FS_IOC_FIEMAP, fiemap_buf); ... It's caused by an overflow in __get_data_block(): ... bh->b_size = map.m_len << inode->i_blkbits; ... map.m_len is an unsigned int, and bh->b_size is a size_t which is 64 bits on 64 bits archtecture, type conversion from an unsigned int to a size_t will result in an overflow. In the above-mentioned case, bh->b_size will be zero, and f2fs_fiemap() will call get_data_block() at block 0 again an again. Fix this by adding a force conversion before left shift. Signed-off-by: Wei Fang Acked-by: Chao Yu Signed-off-by: Jaegeuk Kim Cc: Guenter Roeck Signed-off-by: Greg Kroah-Hartman --- fs/f2fs/data.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -844,7 +844,7 @@ static int __get_data_block(struct inode if (!ret) { map_bh(bh, inode->i_sb, map.m_pblk); bh->b_state = (bh->b_state & ~F2FS_MAP_FLAGS) | map.m_flags; - bh->b_size = map.m_len << inode->i_blkbits; + bh->b_size = (u64)map.m_len << inode->i_blkbits; } return ret; }