From nobody Fri Dec 19 17:17:32 2025 Received: from mail-pl1-f182.google.com (mail-pl1-f182.google.com [209.85.214.182]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AE4FA159569 for ; Tue, 23 Jan 2024 00:29:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705969744; cv=none; b=QelEBXC3+6Z4FvGncuAF/KOAWHMMQlnpuIlq3VPh9GhY0mGZfhDMmxrltTH0xRldDW15/b3v0WIRViQn6J1JPAapntdprlAxZBf0GV4PgDMLO7jOYKJUEmtnSbcmsjSE23YGj97HlVLTBF2KuZry65guoOypYu/R6YFF6Lg6CYA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705969744; c=relaxed/simple; bh=wdQCpDFkq2XNuS6vp7VN0jrvsBX8D7+SnBrIJMJ3N+Q=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=hs5KR8/H9NiODKumsA/v6CWZ1BNrOT4YbIiyJyoBmEj/TiDyyAMt4OG4BA4YtVxdn+orjK4eiZFjq6hiS9uzGKWgfndxJS/TtbbFBWepRqTR0xozoBh7Fq+6ITO5vgepePPTzOmcDYhUVR2YyF6LXYm3Semv1zg8zjMdnh/tugc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org; spf=pass smtp.mailfrom=chromium.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b=gbjQENA/; arc=none smtp.client-ip=209.85.214.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=chromium.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="gbjQENA/" Received: by mail-pl1-f182.google.com with SMTP id d9443c01a7336-1d72f71f222so9661345ad.1 for ; Mon, 22 Jan 2024 16:29:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1705969742; x=1706574542; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=CVxLR6f7iEMo7TAEPfaWn9vwjcL8lBg/KdBkMw33Rxo=; b=gbjQENA/8g5meX6QjWQL1VbfGuh0/U5pkhiX9v6A0uBKibyG7MkLhMXLsJXz89Jj3+ 8VPauqfi6YbErj6VO/sc8GwmGZj0Xi7nP9/QxKC9ZGJZ6JOY6TqQeAjJE+GE7zV2G9b9 5UAv7JlyxKoFunZIQ77vQG0GtOxRKfYNjLFJA= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1705969742; x=1706574542; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=CVxLR6f7iEMo7TAEPfaWn9vwjcL8lBg/KdBkMw33Rxo=; b=T2BwbbJqlwT/trD1NLy3gM4R1FLsPqVY9ZSrzbgQwvsjmSWuCgHInZO5ti6xWIbReo MH67m7VN3I6TeXLZNVC+SIKYjKtZ1AmXuDKS9rV9hRB20EKCMR7bULAN1cbp9iRhvxgx rzdPtHmiZsKavMbckjpDXvzcjH12u4p5Wr4LDgdhURBQsEjEbRvRrI9x9kVS+8v4Vy2b MqeIaTT9oqWKmikkzsNIDFNmAoNbTscqdVcyVyL7dlSQXw+pDUsiQ/2rTFob5Zvamh/2 Xg4k45/VuDA353rClIv8QzU8HU5dkcd6vWrrHEILBOVSVxaWOs0QP6eYkh7X6UKiR8Ht Yc1g== X-Gm-Message-State: AOJu0YztxcudnGbZ0z3q3hIx05vip/wNMt3D9BXjoHJH4tqZOVKrYOq+ crMUQRW/Boizo88zKiV1cm0dGEZyUIALs1rPuAlYuZuIxj8h+464RHd9d5r1BFncz14gYN9rOl0 = X-Google-Smtp-Source: AGHT+IEn/houl8Yw8FvYMNWC3B8MV8/fbDL4xsjwCWUCzj3v1wRhUvEgEWe5QKZnRXFlO7vX6H4DSA== X-Received: by 2002:a17:902:f54e:b0:1d7:1e0c:f994 with SMTP id h14-20020a170902f54e00b001d71e0cf994mr3335214plf.45.1705969742100; Mon, 22 Jan 2024 16:29:02 -0800 (PST) Received: from www.outflux.net ([198.0.35.241]) by smtp.gmail.com with ESMTPSA id mp11-20020a170902fd0b00b001d75ea44323sm1403673plb.21.2024.01.22.16.28.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 22 Jan 2024 16:28:52 -0800 (PST) From: Kees Cook To: linux-hardening@vger.kernel.org Cc: Kees Cook , Jaegeuk Kim , Chao Yu , linux-f2fs-devel@lists.sourceforge.net, "Gustavo A. R. Silva" , Bill Wendling , Justin Stitt , linux-kernel@vger.kernel.org Subject: [PATCH 52/82] f2fs: Refactor intentional wrap-around test Date: Mon, 22 Jan 2024 16:27:27 -0800 Message-Id: <20240123002814.1396804-52-keescook@chromium.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240122235208.work.748-kees@kernel.org> References: <20240122235208.work.748-kees@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2415; i=keescook@chromium.org; h=from:subject; bh=wdQCpDFkq2XNuS6vp7VN0jrvsBX8D7+SnBrIJMJ3N+Q=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBlrwgJyxtpoS8kJtZtyqL6hKLCRushNAde9dDbx HeAgwOgglaJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCZa8ICQAKCRCJcvTf3G3A JqIBEAChZM9m9U2HlElYvUdy9F0F0UgsceQedYYNLYx0L54ESBSelfc98YP9tUZ1jkRspBdT1nC kijkb49E/qqF4YrjskPndLLLfvxjkzUksvg4xoaV5zyEKUTWNlk+oQ/70241cKc8IGAhpPwQl3j IP8LyEb8hrqYd1Gwv05+R/n7XJtH322XuuaSm+VUm++KmFC8YDRf3YRRQE65fPEC2kqrYnLank5 +wDA7XxfBHYZ5VFHofOMUuKsBwQfmE9o8FtseQm0z4Bo1FQS3oSxQvE673WVKQhVmEwmbOR9ivC R5t6LF2QsZrbGDhITRyjy42nBPee5QFqI09uFA+RqI1xhZr+sXi7cXkvN9jzsy4GbJhquMIvoaG 3y4wcyaqW0M1xPODI0RUOvqlK8vgezTN7sWCM6fcp3eFDI10YvIpiRlsN806ofvtT9OS4OdKak+ ANIM9E3Ui3D5E/mxLwKbgarX5fgYxrdlwUSwgNaF75JxNETK7fusGPTtlmfq8XYfUeQu9bRajgR +XeU5K2axNZCgiE9Kza8K/h1REqqfniSyTWXH5qJS4mqpQk9QgxZgIowNKo/wodiPFN53Bo4WJB U5AlyxuOYHJ5rJtrcYirdcrjdv8FILsJ1P8owWZ3SVw0FjZ+qasWTxpHjLsDEI64mmy7fuXj1wv UMcFg1tT7pui2bw== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" In an effort to separate intentional arithmetic wrap-around from unexpected wrap-around, we need to refactor places that depend on this kind of math. One of the most common code patterns of this is: VAR + value < VAR Notably, this is considered "undefined behavior" for signed and pointer types, which the kernel works around by using the -fno-strict-overflow option in the build[1] (which used to just be -fwrapv). Regardless, we want to get the kernel source to the position where we can meaningfully instrument arithmetic wrap-around conditions and catch them when they are unexpected, regardless of whether they are signed[2], unsigned[3], or pointer[4] types. Refactor open-coded wrap-around addition test to use add_would_overflow(). This paves the way to enabling the wrap-around sanitizers in the future. Link: https://git.kernel.org/linus/68df3755e383e6fecf2354a67b08f92f18536594= [1] Link: https://github.com/KSPP/linux/issues/26 [2] Link: https://github.com/KSPP/linux/issues/27 [3] Link: https://github.com/KSPP/linux/issues/344 [4] Cc: Jaegeuk Kim Cc: Chao Yu Cc: linux-f2fs-devel@lists.sourceforge.net Signed-off-by: Kees Cook --- fs/f2fs/file.c | 2 +- fs/f2fs/verity.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index b58ab1157b7e..6360efb98f64 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -2819,7 +2819,7 @@ static int f2fs_move_file_range(struct file *file_in,= loff_t pos_in, } =20 ret =3D -EINVAL; - if (pos_in + len > src->i_size || pos_in + len < pos_in) + if (pos_in + len > src->i_size || add_would_overflow(pos_in, len)) goto out_unlock; if (len =3D=3D 0) olen =3D len =3D src->i_size - pos_in; diff --git a/fs/f2fs/verity.c b/fs/f2fs/verity.c index 4fc95f353a7a..b641cb8d75e8 100644 --- a/fs/f2fs/verity.c +++ b/fs/f2fs/verity.c @@ -237,7 +237,7 @@ static int f2fs_get_verity_descriptor(struct inode *ino= de, void *buf, pos =3D le64_to_cpu(dloc.pos); =20 /* Get the descriptor */ - if (pos + size < pos || pos + size > inode->i_sb->s_maxbytes || + if (add_would_overflow(pos, size) || pos + size > inode->i_sb->s_maxbytes= || pos < f2fs_verity_metadata_pos(inode) || size > INT_MAX) { f2fs_warn(F2FS_I_SB(inode), "invalid verity xattr"); f2fs_handle_error(F2FS_I_SB(inode), --=20 2.34.1