From patchwork Mon Jul 27 17:41:58 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 11687363 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 25CA714B7 for ; Mon, 27 Jul 2020 17:42:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 09AC62078A for ; Mon, 27 Jul 2020 17:42:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595871774; bh=ozOE6UcON1RhZRLjtldC0B+EDLULU+0SvtdCa41mDdc=; h=From:To:Cc:Subject:Date:List-ID:From; b=tsUmFL7kTl0+GB60OlLUStHH89iw8lKHgdyLCtgcODwbqmZyOkORBaQ0Vtvr8UjuJ +AQaePoKxTcIAz3BrXW45P3vBdNkgAz8yfuxHc/tHgq3qQ3kPL17KrO5Ae9BkWkfpk xzWfGdjtD6w86laYooy2QXTZYHLScOlG2CI49mA0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730893AbgG0Rmx (ORCPT ); Mon, 27 Jul 2020 13:42:53 -0400 Received: from mail.kernel.org ([198.145.29.99]:36790 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729097AbgG0Rmx (ORCPT ); Mon, 27 Jul 2020 13:42:53 -0400 Received: from sol.hsd1.ca.comcast.net (c-107-3-166-239.hsd1.ca.comcast.net [107.3.166.239]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AA0AD20714; Mon, 27 Jul 2020 17:42:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595871772; bh=ozOE6UcON1RhZRLjtldC0B+EDLULU+0SvtdCa41mDdc=; h=From:To:Cc:Subject:Date:From; b=LBdDwGb+BxMrhL4dI59/DVNUo1GjKSYw9URg4Hdmy6WB9h2T62oHc1A0I16S8ljl5 p+CHUA2oy0y3SbsAUmcAwQjQG5cYXYlPo0dIM/Y0h7r8X3w3buT6d7oKCvoh2+fpwP M+QvmPMnjg/IvpmdNKk4ahflJ0mRWcmjC968YWAA= From: Eric Biggers To: linux-fscrypt@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, Satya Tangirala , Dave Chinner Subject: [PATCH] fscrypt: don't load ->i_crypt_info before it's known to be valid Date: Mon, 27 Jul 2020 10:41:58 -0700 Message-Id: <20200727174158.121456-1-ebiggers@kernel.org> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Eric Biggers In fscrypt_set_bio_crypt_ctx(), ->i_crypt_info isn't known to be non-NULL until we check fscrypt_inode_uses_inline_crypto(). So, load ->i_crypt_info after the check rather than before. This makes no difference currently, but it prevents people from introducing bugs where the pointer is dereferenced when it may be NULL. Suggested-by: Dave Chinner Cc: Satya Tangirala Signed-off-by: Eric Biggers --- fs/crypto/inline_crypt.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/crypto/inline_crypt.c b/fs/crypto/inline_crypt.c index dfb06375099ae..b6b8574caa13c 100644 --- a/fs/crypto/inline_crypt.c +++ b/fs/crypto/inline_crypt.c @@ -244,11 +244,12 @@ static void fscrypt_generate_dun(const struct fscrypt_info *ci, u64 lblk_num, void fscrypt_set_bio_crypt_ctx(struct bio *bio, const struct inode *inode, u64 first_lblk, gfp_t gfp_mask) { - const struct fscrypt_info *ci = inode->i_crypt_info; + const struct fscrypt_info *ci; u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE]; if (!fscrypt_inode_uses_inline_crypto(inode)) return; + ci = inode->i_crypt_info; fscrypt_generate_dun(ci, first_lblk, dun); bio_crypt_set_ctx(bio, &ci->ci_enc_key.blk_key->base, dun, gfp_mask);