From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gnu.wildebeest.org (wildebeest.demon.nl [212.238.236.112]) by sourceware.org (Postfix) with ESMTPS id 114AC386F43F for ; Sun, 7 Jun 2020 14:51:29 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 114AC386F43F Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=klomp.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=mark@klomp.org Received: from tarox.wildebeest.org (tarox.wildebeest.org [172.31.17.39]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by gnu.wildebeest.org (Postfix) with ESMTPSA id C6D5130291AA; Sun, 7 Jun 2020 16:51:26 +0200 (CEST) Received: by tarox.wildebeest.org (Postfix, from userid 1000) id 757AB413CC40; Sun, 7 Jun 2020 16:51:26 +0200 (CEST) From: Mark Wielaard To: elfutils-devel@sourceware.org Cc: Mark Wielaard Subject: [PATCH] nm: Handle corrupt symbol name table. Date: Sun, 7 Jun 2020 16:51:24 +0200 Message-Id: <20200607145124.32214-1-mark@klomp.org> X-Mailer: git-send-email 2.18.4 X-Spam-Status: No, score=-12.7 required=5.0 tests=BAYES_00, GIT_PATCH_0, JMQ_SPF_NEUTRAL, KAM_DMARC_STATUS, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: elfutils-devel@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Elfutils-devel mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 07 Jun 2020 14:51:32 -0000 We try to sort symbol by name (when neither -n nor -p are given). This could crash if the symbol name table was corrupt. Use elf_strptr to get the symbol name and use the empty string in case a name couldn't be found. Signed-off-by: Mark Wielaard --- src/ChangeLog | 8 ++++++++ src/nm.c | 15 +++++++++------ 2 files changed, 17 insertions(+), 6 deletions(-) diff --git a/src/ChangeLog b/src/ChangeLog index 4684d332..512d7b54 100644 --- a/src/ChangeLog +++ b/src/ChangeLog @@ -1,3 +1,11 @@ +2020-06-07 Mark Wielaard + + * nm.c (sort_by_name_strtab): Replace by... + (sort_by_name_elf): New static Elf pointer and ... + (sort_by_name_ndx): New static size_t index. + (sort_by_name): Use elf_strptr to get symbol string. + (show_symbols): Set sort_by_name_elf and sort_by_name_ndx. + 2020-06-06 Mark Wielaard * nm.c (show_symbols_sysv): Skip no name and STT_FILE symbols. diff --git a/src/nm.c b/src/nm.c index 8302a98c..a6334743 100644 --- a/src/nm.c +++ b/src/nm.c @@ -1,5 +1,5 @@ /* Print symbol information from ELF file in human-readable form. - Copyright (C) 2000-2008, 2009, 2011, 2012, 2014, 2015 Red Hat, Inc. + Copyright (C) 2000-2008, 2009, 2011, 2012, 2014, 2015, 2020 Red Hat, Inc. This file is part of elfutils. Written by Ulrich Drepper , 2000. @@ -1153,7 +1153,8 @@ sort_by_address (const void *p1, const void *p2) return reverse_sort ? -result : result; } -static Elf_Data *sort_by_name_strtab; +static Elf *sort_by_name_elf; +static size_t sort_by_name_ndx; static int sort_by_name (const void *p1, const void *p2) @@ -1161,8 +1162,10 @@ sort_by_name (const void *p1, const void *p2) GElf_SymX *s1 = (GElf_SymX *) p1; GElf_SymX *s2 = (GElf_SymX *) p2; - const char *n1 = sort_by_name_strtab->d_buf + s1->sym.st_name; - const char *n2 = sort_by_name_strtab->d_buf + s2->sym.st_name; + const char *n1 = elf_strptr (sort_by_name_elf, sort_by_name_ndx, + s1->sym.st_name) ?: ""; + const char *n2 = elf_strptr (sort_by_name_elf, sort_by_name_ndx, + s2->sym.st_name) ?: ""; int result = strcmp (n1, n2); @@ -1475,8 +1478,8 @@ show_symbols (int fd, Ebl *ebl, GElf_Ehdr *ehdr, /* Sort the entries according to the users wishes. */ if (sort == sort_name) { - sort_by_name_strtab = elf_getdata (elf_getscn (ebl->elf, shdr->sh_link), - NULL); + sort_by_name_elf = ebl->elf; + sort_by_name_ndx = shdr->sh_link; qsort (sym_mem, nentries, sizeof (GElf_SymX), sort_by_name); } else if (sort == sort_numeric) -- 2.18.4