From ba7139188c75a9c620cadea59158c5ffcab28acf Mon Sep 17 00:00:00 2001 From: Alex Lindsay Date: Thu, 17 Aug 2017 11:53:53 +0100 Subject: [PATCH] Synthetic symbol leak in elf_read_minimal_symbols Detected this leak with valgrind memcheck: ==30840== 194 bytes in 1 blocks are definitely lost in loss record 9,138 of 10,922 ==30840== at 0x4C2DB8F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==30840== by 0x80DF82: bfd_malloc (libbfd.c:193) ==30840== by 0x80E12D: bfd_zmalloc (libbfd.c:278) ==30840== by 0x819E80: elf_x86_64_get_synthetic_symtab (elf64-x86-64.c:6835) ==30840== by 0x4F7B01: elf_read_minimal_symbols(objfile*, int, elfinfo const*) (elfread.c:1124) ==30840== by 0x4F7CE7: elf_symfile_read(objfile*, enum_flags) (elfread.c:1182) ==30840== by 0x7557FC: read_symbols(objfile*, enum_flags) (symfile.c:861) ==30840== by 0x755EE1: syms_from_objfile_1(objfile*, section_addr_info*, enum_flags) (symfile.c:1062) We perform a dynamic allocation in elf64-x86-64.c:elf_x86_64_get_synthetic_symtab s = *ret = (asymbol *) bfd_zmalloc (size); that appear to never get freed. gdb: 2017-08-17 Alex Lindsay * elfread.c (elf_read_minimal_symbols): xfree synthsyms. --- gdb/ChangeLog | 4 ++++ gdb/elfread.c | 3 +++ 2 files changed, 7 insertions(+) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 10d63b0ee1..d2c194eff3 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,7 @@ +2017-08-17 Alex Lindsay (tiny change) + + * elfread.c (elf_read_minimal_symbols): xfree synthsyms. + 2017-08-17 Ruslan Kabatsayev * NEWS: Mention new shortcuts for nexti and stepi in TUI diff --git a/gdb/elfread.c b/gdb/elfread.c index ece704ca7c..a654661335 100644 --- a/gdb/elfread.c +++ b/gdb/elfread.c @@ -1132,6 +1132,9 @@ elf_read_minimal_symbols (struct objfile *objfile, int symfile_flags, synth_symbol_table[i] = synthsyms + i; elf_symtab_read (reader, objfile, ST_SYNTHETIC, synthcount, synth_symbol_table.get (), true); + + xfree (synthsyms); + synthsyms = NULL; } /* Install any minimal symbols that have been collected as the current -- 2.34.1