From patchwork Mon May 25 05:47:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 11568085 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 17F8A1392 for ; Mon, 25 May 2020 05:47:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0072020849 for ; Mon, 25 May 2020 05:47:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590385652; bh=5k6xz6TuiGF+ullAgZUvDOvOMPBANbKX9OHAS2NHpS0=; h=From:To:Cc:Subject:Date:List-ID:From; b=msAfVAWrVEM0bMxfJwgR9wHCr3TP7JpJx7YgGZorWFhSrAo9Ya50VXlcsXxr2Z4ru hNWTbbQ+DiIRce2uANcIPZJgb5aoZLinI+7F9hR38tYRcOHE3NwO0YnFOWCIay0v6T FUrILMGnevC7G2bzKBEK9F/aJLnF1dnOxhtnXvwg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388743AbgEYFrb (ORCPT ); Mon, 25 May 2020 01:47:31 -0400 Received: from conuserg-10.nifty.com ([210.131.2.77]:62121 "EHLO conuserg-10.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388745AbgEYFr2 (ORCPT ); Mon, 25 May 2020 01:47:28 -0400 Received: from oscar.flets-west.jp (softbank126090202047.bbtec.net [126.90.202.47]) (authenticated) by conuserg-10.nifty.com with ESMTP id 04P5l9A0013208; Mon, 25 May 2020 14:47:09 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-10.nifty.com 04P5l9A0013208 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1590385629; bh=U5HG07zP7ca2X4TcXFbTL58H0LBgSxaGOS7/4KlXXDA=; h=From:To:Cc:Subject:Date:From; b=tJu2whngR2eETQTKf6XrEQ1x1oU4lWGbp0+qxZY3OyjIafyL0Zqx4Dv54dXAId8AI fym6mc89UU9m9IoFCIPMc0AQWbPWRCPMVSy6KigYe/Gd7TMo2plCWnzvMJ4+C7dE7f sdcIysmx6GXVdbpBE1n5Qb+DALmLnTZzVcql3SBFVlVLr7FLiF7J+zkCtyOxNjApgK C70Um/Z4sXJfn3O0Q4XfidDrSm2DXnpQGnz91kBUE+fMLk9GlBGvfmpUNVSNRAWkDn bJEzKHwmL8mkqVdFQYaLlZ43D0OvgbadIOtTeSt5VG8Jl0sjTfHrTkV9yp4W1jOSa3 cuVKTbahF5QnQ== X-Nifty-SrcIP: [126.90.202.47] From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: Masahiro Yamada , Michal Marek , linux-kernel@vger.kernel.org Subject: [PATCH 1/2] modpost: fix potential segmentation fault for addend_i386_rel() Date: Mon, 25 May 2020 14:47:04 +0900 Message-Id: <20200525054705.1066033-1-masahiroy@kernel.org> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org This may not be a practical problem, but the second pass of ARCH=i386 modpost causes segmentation fault if the -s option is not passed. MODPOST 12 modules Segmentation fault (core dumped) make[2]: *** [scripts/Makefile.modpost:94: __modpost] Error 139 make[1]: *** [Makefile:1339: modules] Error 2 make[1]: *** Waiting for unfinished jobs.... The segmentation fault occurs when section_rel() is called for vmlinux, which is untested in regular builds. The cause of the problem is reloc_location() returns a wrong pointer for ET_EXEC object type. In this case, you need to subtract sechdr->sh_addr, otherwise it would get access beyond the mmap'ed memory. Add sym_get_data_offset() helper to avoid code duplication. Signed-off-by: Masahiro Yamada --- scripts/mod/modpost.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 34f2aa3a021f..a8306adb3554 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -345,19 +345,23 @@ static const char *sec_name(struct elf_info *elf, int secindex) return sech_name(elf, &elf->sechdrs[secindex]); } -static void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym) +static void *sym_get_data_offset(const struct elf_info *info, + unsigned int secindex, unsigned long offset) { - unsigned int secindex = get_secindex(info, sym); Elf_Shdr *sechdr = &info->sechdrs[secindex]; - unsigned long offset; - offset = sym->st_value; if (info->hdr->e_type != ET_REL) offset -= sechdr->sh_addr; return (void *)info->hdr + sechdr->sh_offset + offset; } +static void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym) +{ + return sym_get_data_offset(info, get_secindex(info, sym), + sym->st_value); +} + #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0) static enum export export_from_secname(struct elf_info *elf, unsigned int sec) @@ -1761,11 +1765,7 @@ static void check_section_mismatch(const char *modname, struct elf_info *elf, static unsigned int *reloc_location(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) { - Elf_Shdr *sechdrs = elf->sechdrs; - int section = sechdr->sh_info; - - return (void *)elf->hdr + sechdrs[section].sh_offset + - r->r_offset; + return sym_get_data_offset(elf, sechdr->sh_info, r->r_offset); } static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r) From patchwork Mon May 25 05:47:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 11568083 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 CDFCC60D for ; Mon, 25 May 2020 05:47:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B47D120849 for ; Mon, 25 May 2020 05:47:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590385651; bh=rVU0ew6POXDDT3J60biapHGUo6nBMyPT1PuwG9sBae8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=uqVwMVRSer/OOY7mIZFntDMnxuBxMxswwYSo+2TJYXl7JhbMCeEupMNnHAJ4HrySJ oNj537jjBpNqm5fO+Gj1g/MWBI0IP+gK6xtGLvPkEnrRjCVQrhbpCd+xzmUNwkNzdx V/9+XXkkF6Rvvo3mMJlS6w8dDRXEwzLISalEYBl4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388508AbgEYFr2 (ORCPT ); Mon, 25 May 2020 01:47:28 -0400 Received: from conuserg-10.nifty.com ([210.131.2.77]:62120 "EHLO conuserg-10.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388743AbgEYFr1 (ORCPT ); Mon, 25 May 2020 01:47:27 -0400 Received: from oscar.flets-west.jp (softbank126090202047.bbtec.net [126.90.202.47]) (authenticated) by conuserg-10.nifty.com with ESMTP id 04P5l9A1013208; Mon, 25 May 2020 14:47:10 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conuserg-10.nifty.com 04P5l9A1013208 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1590385630; bh=0uTKdW1KbUmtGYeOi/qQd7Taz/4BizcEeyoYfCw1RgQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vVbOCC+QI3UNPkBYtTTGyY+sFEk9ccI3jons1o/CoGQ1wWDz0lYwYbr1cfmhEHNoj LqSKxcvue3yJRwVbDLUcJpqFN/4cDuJ8ZXq1hFM0Idg965qxCPijV2i/Hek5D4GlwC R3UZf94I4xibS7241/Og2YFVhB1vdL4F80VhHfpbMf31K742saq7Gxn8xVmERIxIqq 5RPrAeWSAN3I7kadidHG0u04EIA9Oo46hE03OP2HEN2p7iSBRxWiIu+eYN6HDFoVva wnzEKpkB4AcxgiX7NImOvp+WbE85U41eZ8hshxBMaxoSrqNLOvpZtfhYuc7adDp8sD 2lqrBWjHTMw8g== X-Nifty-SrcIP: [126.90.202.47] From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: Masahiro Yamada , Michal Marek , linux-kernel@vger.kernel.org Subject: [PATCH 2/2] modpost: refactor sech_name() Date: Mon, 25 May 2020 14:47:05 +0900 Message-Id: <20200525054705.1066033-2-masahiroy@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200525054705.1066033-1-masahiroy@kernel.org> References: <20200525054705.1066033-1-masahiroy@kernel.org> MIME-Version: 1.0 Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org Use sym_get_data_offset() helper to get access to the .shstrtab section data. No functional change is intended because elf->sechdrs[elf->secindex_strings].sh_addr is 0 for both ET_REL and ET_EXEC object types. Signed-off-by: Masahiro Yamada --- scripts/mod/modpost.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index a8306adb3554..a5f3908bc9e4 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -333,18 +333,6 @@ static enum export export_no(const char *s) return export_unknown; } -static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr) -{ - return (void *)elf->hdr + - elf->sechdrs[elf->secindex_strings].sh_offset + - sechdr->sh_name; -} - -static const char *sec_name(struct elf_info *elf, int secindex) -{ - return sech_name(elf, &elf->sechdrs[secindex]); -} - static void *sym_get_data_offset(const struct elf_info *info, unsigned int secindex, unsigned long offset) { @@ -362,6 +350,16 @@ static void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym) sym->st_value); } +static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr) +{ + return sym_get_data_offset(elf, elf->secindex_strings, sechdr->sh_name); +} + +static const char *sec_name(struct elf_info *elf, int secindex) +{ + return sech_name(elf, &elf->sechdrs[secindex]); +} + #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0) static enum export export_from_secname(struct elf_info *elf, unsigned int sec)