Date: Wed, 8 Jun 2016 04:49:21 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r301581 - stable/10/libexec/rtld-elf Message-ID: <201606080449.u584nLS7035412@repo.freebsd.org>
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Author: kib Date: Wed Jun 8 04:49:20 2016 New Revision: 301581 URL: https://svnweb.freebsd.org/changeset/base/301581 Log: MFC r300691: Fix issues found by Coverity in the rtld-elf.c:gethints(). Modified: stable/10/libexec/rtld-elf/rtld.c Directory Properties: stable/10/ (props changed) Modified: stable/10/libexec/rtld-elf/rtld.c ============================================================================== --- stable/10/libexec/rtld-elf/rtld.c Wed Jun 8 04:37:03 2016 (r301580) +++ stable/10/libexec/rtld-elf/rtld.c Wed Jun 8 04:49:20 2016 (r301581) @@ -1623,14 +1623,16 @@ static const char * gethints(bool nostdlib) { static char *hints, *filtered_path; - struct elfhints_hdr hdr; + static struct elfhints_hdr hdr; struct fill_search_info_args sargs, hargs; struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; struct dl_serpath *SLPpath, *hintpath; char *p; + struct stat hint_stat; unsigned int SLPndx, hintndx, fndx, fcount; int fd; size_t flen; + uint32_t dl; bool skip; /* First call, read the hints file */ @@ -1640,19 +1642,38 @@ gethints(bool nostdlib) if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) return (NULL); + + /* + * Check of hdr.dirlistlen value against type limit + * intends to pacify static analyzers. Further + * paranoia leads to checks that dirlist is fully + * contained in the file range. + */ if (read(fd, &hdr, sizeof hdr) != sizeof hdr || hdr.magic != ELFHINTS_MAGIC || - hdr.version != 1) { + hdr.version != 1 || hdr.dirlistlen > UINT_MAX / 2 || + fstat(fd, &hint_stat) == -1) { +cleanup1: close(fd); + hdr.dirlistlen = 0; return (NULL); } + dl = hdr.strtab; + if (dl + hdr.dirlist < dl) + goto cleanup1; + dl += hdr.dirlist; + if (dl + hdr.dirlistlen < dl) + goto cleanup1; + dl += hdr.dirlistlen; + if (dl > hint_stat.st_size) + goto cleanup1; p = xmalloc(hdr.dirlistlen + 1); + if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 || read(fd, p, hdr.dirlistlen + 1) != - (ssize_t)hdr.dirlistlen + 1) { + (ssize_t)hdr.dirlistlen + 1 || p[hdr.dirlistlen] != '\0') { free(p); - close(fd); - return (NULL); + goto cleanup1; } hints = p; close(fd); @@ -1685,7 +1706,7 @@ gethints(bool nostdlib) hargs.serinfo = &hmeta; path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs); - path_enumerate(p, fill_search_info, &hargs); + path_enumerate(hints, fill_search_info, &hargs); SLPinfo = xmalloc(smeta.dls_size); hintinfo = xmalloc(hmeta.dls_size); @@ -1704,7 +1725,7 @@ gethints(bool nostdlib) hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs); - path_enumerate(p, fill_search_info, &hargs); + path_enumerate(hints, fill_search_info, &hargs); /* * Now calculate the difference between two sets, by excluding
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