From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DD866377EDC; Fri, 4 Sep 2026 05:50:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788501038; cv=none; b=MRPWj2g7Dlz+tKkp7EInzAUqyyEpgc2qbevsUiT6GK8YK6oa3kWlYZC/oo50mau4clYvJSSAJRYWIhMfu//rX2AWPFbAyAihaROgC9nlyb2LP86gmGrc+6V2vhQik+yMfUXuS2SCjouCJyMWiCsgNNf9P470WUqzalYQ0wdwqtY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788501038; c=relaxed/simple; bh=ugHSUGosk2CyXUiJifjfVmJKHRskBTfWuZNfQ/MO+0M=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=FmL3O0Srw6/qetjv0P5VZnQCE4C71cy7m7XX8Io8ypJX9RnfORbQP4Xqt9s/XCF0PrtfB5UhxegBYHYHPMYvmWJK/qSQFV3d1Km932x+VMt/qKk88n8X926HHhhRhpFPd0DSuJXQzp0DG1E0rj4mwvRnv2qb9ifMqo5fl8GFkt4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=uCe4Q2Qg; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="uCe4Q2Qg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 446751F00A3E; Fri, 4 Sep 2026 05:50:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788501036; bh=DSNwGjw2IpcKIWSmNofoYwtO1aZ+wQIn7GByziZCd8g=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=uCe4Q2QgdQVhfRYYigR2wyzGBBXD0AfL/wR+DRWjAZJ2Pw5aPapoU5SBtN6iPu2+T rTGd+v2RXAdtTNYggGcjh0wSZFFZ5vSEfJs3Djs18mvN6HrpEZe6X9ioPCFH5+bRhs 41uUhOt5WOyoL9vNeOjlcb1+vBzOf0cK4tjpla3w= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?Thi=C3=A9baud=20Weksteen?= , Aaron Tomlin , Petr Pavlu Subject: [PATCH 6.18 269/552] module: validate string table section types Date: Fri, 4 Sep 2026 06:57:06 +0200 Message-ID: <20260904045756.073322686@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260904045747.813364717@linuxfoundation.org> References: <20260904045747.813364717@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Thiébaud Weksteen commit 9a5ff45689329835f874cefe5174e577d141d423 upstream. In elf_validity_cache_sechdrs, section sizes and offsets are validated, unless the section type is SHT_NULL or SHT_NOBITS. Later, elf_validity_cache_secstrings and elf_validity_cache_index_str access the section name table (.shstrtab) and symbol string table (.strtab) headers without first ensuring that their types are SHT_STRTAB. If a section type is SHT_NULL or SHT_NOBITS, sh_offset has not been validated and may reference out-of-bounds memory when dereferenced in elf_validity_cache_secstrings or elf_validity_cache_strtab. Validate that both string section headers are of type SHT_STRTAB before caching them. Cc: stable@vger.kernel.org Signed-off-by: Thiébaud Weksteen Reviewed-by: Aaron Tomlin Reviewed-by: Petr Pavlu Signed-off-by: Petr Pavlu Signed-off-by: Greg Kroah-Hartman --- kernel/module/main.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -1958,6 +1958,7 @@ static int elf_validity_cache_sechdrs(st * Specifically checks: * * * Section name table index is inbounds of section headers + * * Section name table type is SHT_STRTAB * * Section name table is not empty * * Section name table is NUL terminated * * All section name offsets are inbounds of the section @@ -1985,6 +1986,11 @@ static int elf_validity_cache_secstrings strhdr = &info->sechdrs[info->hdr->e_shstrndx]; + if (strhdr->sh_type != SHT_STRTAB) { + pr_err("Invalid ELF section name table type: %u\n", strhdr->sh_type); + return -ENOEXEC; + } + /* * The section name table must be NUL-terminated, as required * by the spec. This makes strcmp and pr_* calls that access @@ -2151,7 +2157,7 @@ static int elf_validity_cache_index_sym( * 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. + * in-bounds and of type SHT_STRTAB, and caches it. * * Return: %0 if valid, %-ENOEXEC on failure. */ @@ -2165,6 +2171,12 @@ static int elf_validity_cache_index_str( return -ENOEXEC; } + if (info->sechdrs[str_idx].sh_type != SHT_STRTAB) { + pr_err("Invalid ELF symbol string table type: %u\n", + info->sechdrs[str_idx].sh_type); + return -ENOEXEC; + } + info->index.str = str_idx; return 0; }