From nobody Sun Feb 8 03:12:30 2026 Received: from mail-yb1-f202.google.com (mail-yb1-f202.google.com [209.85.219.202]) (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 709B71AD401 for ; Tue, 24 Sep 2024 21:20:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727212851; cv=none; b=pe6h7CqVLKeQwHU0352fkGdeoFmCps3tfp54qAXWIQthIl6fn3E/gQb9FKTvMAS0ebPJs3FPGl2+qnAf8VknZ9+fYdVucmKSiVLk7wzQJMFvM4rkLoh5mmNd5kKlBST3D5NZlptJhGOZ7S7RBMtls1o2oiPFgpeytKZJ5+9J5os= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727212851; c=relaxed/simple; bh=wM975yYhhnJbskoT3Xe/Z8RaXLTIAwoZIK7NoqKeDB8=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=je4RyE0yTcFewcj/rAMPRo22jCaG8V5VHKFvM7jnP5jKfEyqLCpVAtLfPjWyGucs9cbn9XnzEcAfwdyf6fKu1KUanXNcQMG8vN9ZtTbPGxe6kpn2zF0ZePB0l9hCVf8QIrJ3jWtA6ckPepccheFFYDxr+D8GiM0uWsyBghf1zZU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--mmaurer.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=DFQA/zpZ; arc=none smtp.client-ip=209.85.219.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--mmaurer.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="DFQA/zpZ" Received: by mail-yb1-f202.google.com with SMTP id 3f1490d57ef6-e201a37e5a4so9615130276.0 for ; Tue, 24 Sep 2024 14:20:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1727212848; x=1727817648; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=fOjsxdYdAkInxupUorws184MmwFGmal1AWb/bAcHrOQ=; b=DFQA/zpZZMMwsPS9NnAIH9GEcWUkeezEU6kmEHTSwBgmKDWaYUSb7vInK/1x6jdTH6 nD/+H2m9fC2jgdIK7gPFhCJZQ2odzNL5rK6TTBQvVRZJ9sOBj21YOf4W5LnLCSMjKCNi uEQoHAHWsn9Svu+3R4mAlEK1N0SPsIhaqW7Brd25VG2XNLMy55FDRR7sn8G8iy41tPYT iCs4zvLK9kOxvsgjKQUabzxnbsnDZb93EvBHRJf81HwD+0RWxfI2Wx8Ry8pHCiQrMDXG 5QR/GaWMeFhyZKs5IvSe6n0q+JbvtifJfv1nmehd4rHwQq3wan8rLDSLYS+FvwDqhezC C70w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1727212848; x=1727817648; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=fOjsxdYdAkInxupUorws184MmwFGmal1AWb/bAcHrOQ=; b=tFLYsnWfe4XwMAo+2rPMkyApHLyQV2Iscs5+qBzvw10Vahz9Usfhuk1SczDfOTq6Fk uZZQdP0dFsbaC68T9HZw4xCX5V1XEmdpKPknXuga/IIRpRTipIX7WvaVQUDKshth3Ahz Mqfb0XqpI5xnl1vIwf/FhJTZ/6IqJ46QLiJqKCZ3X0owsBHe0wbCDypDq9tq8Z/OL3KG GOGPuV21vLiZX36lP48vB4HEKPp3iHsDLz1fm4fdLoHc93+esD+3nsbDq2cI5nhoH+Zp XfzzoUrCM9K+ItxS+pb4f7/KLJuhjT4oPH7e2QnWF30QwUUoOh2pK0HQiw7v5xPeWMoP LklA== X-Forwarded-Encrypted: i=1; AJvYcCUDuz7JiQalXRYB6p+qVzhSCQ1PT+s2tpgjIKFS5znP5SbUA0gVbkZSaL/eYURYzznawqSUPWx1JvkZbVc=@vger.kernel.org X-Gm-Message-State: AOJu0YwoQfBx6Tv3aQT9upZV6atdzCZ7ksO9UKRw0OVp11LnuC/LsUND RlCchsm/acXrJT+iOd4Jm1ETlkGBGB+FOwWUhjJrvMIN615B7xVWsFFRaMgj4Qo/kv3KF/k6182 FBdKvlA== X-Google-Smtp-Source: AGHT+IGFSH/4qSrZBqEqlTh529yD1/WBEgXQbh0dGeEOt+TtZiA9qDu1tsUd11c56UkfBMQHgYlEILsdYk48 X-Received: from anyblade.c.googlers.com ([fda3:e722:ac3:cc00:20:ed76:c0a8:1791]) (user=mmaurer job=sendgmr) by 2002:a25:dc0c:0:b0:e1a:8195:3c1b with SMTP id 3f1490d57ef6-e24d9331a46mr447276.6.1727212848012; Tue, 24 Sep 2024 14:20:48 -0700 (PDT) Date: Tue, 24 Sep 2024 21:19:50 +0000 In-Reply-To: <20240924212024.540574-1-mmaurer@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240924212024.540574-1-mmaurer@google.com> X-Mailer: git-send-email 2.46.1.824.gd892dcdcdd-goog Message-ID: <20240924212024.540574-9-mmaurer@google.com> Subject: [PATCH v4 08/16] module: Factor out elf_validity_cache_index_str From: Matthew Maurer To: masahiroy@kernel.org, ndesaulniers@google.com, ojeda@kernel.org, gary@garyguo.net, mcgrof@kernel.org, Alex Gaynor Cc: rust-for-linux@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, neal@gompa.dev, marcan@marcan.st, j@jannau.net, asahi@lists.linux.dev, Matthew Maurer , Petr Pavlu , Sami Tolvanen , Daniel Gomez , Boqun Feng , "=?UTF-8?q?Bj=C3=B6rn=20Roy=20Baron?=" , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , linux-modules@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Pull out index validation for the symbol string section. Note that this does not validate the *contents* of the string table, only shape and presence of the section. Signed-off-by: Matthew Maurer --- kernel/module/main.c | 37 ++++++++++++++++++++++++++++--------- 1 file changed, 28 insertions(+), 9 deletions(-) diff --git a/kernel/module/main.c b/kernel/module/main.c index 6be58b0a6468..43140475aac0 100644 --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -2014,6 +2014,31 @@ static int elf_validity_cache_index_sym(struct load_= info *info) return 0; } =20 +/** + * elf_validity_cache_index_str() - Validate and cache strtab index + * @info: Load info to cache strtab index in. + * Must have &load_info->sechdrs and &load_info->secstrings populat= ed. + * Must have &load_info->index.sym populated. + * + * Looks at the symbol table's associated string table, makes sure it is + * in-bounds, and caches it. + * + * Return: %0 if valid, %-ENOEXEC on failure. + */ +static int elf_validity_cache_index_str(struct load_info *info) +{ + unsigned int str_idx =3D info->sechdrs[info->index.sym].sh_link; + + if (str_idx =3D=3D SHN_UNDEF || str_idx >=3D info->hdr->e_shnum) { + pr_err("Invalid ELF sh_link!=3DSHN_UNDEF(%d) or (sh_link(%d) >=3D hdr->e= _shnum(%d)\n", + str_idx, str_idx, info->hdr->e_shnum); + return -ENOEXEC; + } + + info->index.str =3D str_idx; + return 0; +} + /* * Check userspace passed ELF module against our expectations, and cache * useful variables for further processing as we go. @@ -2037,7 +2062,6 @@ static int elf_validity_cache_index_sym(struct load_i= nfo *info) static int elf_validity_cache_copy(struct load_info *info, int flags) { int err; - int str_idx; =20 err =3D elf_validity_cache_sechdrs(info); if (err < 0) @@ -2054,16 +2078,11 @@ static int elf_validity_cache_copy(struct load_info= *info, int flags) err =3D elf_validity_cache_index_sym(info); if (err < 0) return err; - - str_idx =3D info->sechdrs[info->index.sym].sh_link; - if (str_idx =3D=3D SHN_UNDEF || str_idx >=3D info->hdr->e_shnum) { - pr_err("Invalid ELF sh_link!=3DSHN_UNDEF(%d) or (sh_link(%d) >=3D hdr->e= _shnum(%d)\n", - str_idx, str_idx, info->hdr->e_shnum); - return -ENOEXEC; - } + err =3D elf_validity_cache_index_str(info); + if (err < 0) + return err; =20 /* Sets internal strings. */ - info->index.str =3D str_idx; info->strtab =3D (char *)info->hdr + info->sechdrs[info->index.str].sh_of= fset; =20 /* This is temporary: point mod into copy of data. */ --=20 2.46.1.824.gd892dcdcdd-goog