From 1a4c27355e146b6d8cc6487b998462c7fdd1048f Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Thu, 11 Apr 2019 18:12:00 -0300 Subject: elf: Fix pldd (BZ#18035) Since 9182aa67994 (Fix vDSO l_name for GDB's, BZ#387) the initial link_map for executable itself and loader will have both l_name and l_libname->name holding the same value due: elf/dl-object.c 95 new->l_name = *realname ? realname : (char *) newname->name + libname_len - 1; Since newname->name points to new->l_libname->name. This leads to pldd to an infinite call at: elf/pldd-xx.c 203 again: 204 while (1) 205 { 206 ssize_t n = pread64 (memfd, tmpbuf.data, tmpbuf.length, name_offset); 228 /* Try the l_libname element. */ 229 struct E(libname_list) ln; 230 if (pread64 (memfd, &ln, sizeof (ln), m.l_libname) == sizeof (ln)) 231 { 232 name_offset = ln.name; 233 goto again; 234 } Since the value at ln.name (l_libname->name) will be the same as previously read. The straightforward fix is just avoid the check and read the new list entry. I checked also against binaries issues with old loaders with fix for BZ#387, and pldd could dump the shared objects. Checked on x86_64-linux-gnu, i686-linux-gnu, aarch64-linux-gnu, and powerpc64le-linux-gnu. [BZ #18035] * elf/Makefile (tests-container): Add tst-pldd. * elf/pldd-xx.c: Use _Static_assert in of pldd_assert. (E(find_maps)): Avoid use alloca, use default read file operations instead of explicit LFS names, and fix infinite loop. * elf/pldd.c: Explicit set _FILE_OFFSET_BITS, cleanup headers. (get_process_info): Use _Static_assert instead of assert, use default directory operations instead of explicit LFS names, and free some leadek pointers. * elf/tst-pldd.c: New file. --- elf/Makefile | 1 + 1 file changed, 1 insertion(+) (limited to 'elf/Makefile') diff --git a/elf/Makefile b/elf/Makefile index 310a37cc13..0b4a877880 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -194,6 +194,7 @@ tests-internal += loadtest unload unload2 circleload1 \ tst-tls3 tst-tls6 tst-tls7 tst-tls8 tst-dlmopen2 \ tst-ptrguard1 tst-stackguard1 tst-libc_dlvsym \ tst-create_format1 +tests-container += tst-pldd ifeq ($(build-hardcoded-path-in-tests),yes) tests += tst-dlopen-aout tst-dlopen-aout-no-pie = yes -- cgit v1.2.3