From 102def4da826b3d9e169741421e5e67e8731909a Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Tue, 23 Oct 2018 18:30:22 +1030 Subject: [PATCH] PR23805, NULL pointer dereference in elf_link_input_bfd PR 23805 * elflink.c (elf_link_input_bfd): Don't segfault on finding STT_TLS symbols without any TLS sections. Instead, change the symbol type to STT_NOTYPE. Upstream-Status: Backport CVE: CVE-2018-18606 Signed-off-by: Zhixiong Chi --- bfd/ChangeLog | 7 +++++++ bfd/elflink.c | 20 ++++++++++++++------ 2 files changed, 21 insertions(+), 6 deletions(-) --- a/bfd/elflink.c +++ b/bfd/elflink.c @@ -10496,8 +10496,11 @@ elf_link_input_bfd (struct elf_final_lin if (ELF_ST_TYPE (osym.st_info) == STT_TLS) { /* STT_TLS symbols are relative to PT_TLS segment base. */ - BFD_ASSERT (elf_hash_table (flinfo->info)->tls_sec != NULL); - osym.st_value -= elf_hash_table (flinfo->info)->tls_sec->vma; + if (elf_hash_table (flinfo->info)->tls_sec != NULL) + osym.st_value -= elf_hash_table (flinfo->info)->tls_sec->vma; + else + osym.st_info = ELF_ST_INFO (ELF_ST_BIND (osym.st_info), + STT_NOTYPE); } } @@ -11053,12 +11056,17 @@ elf_link_input_bfd (struct elf_final_lin sym.st_value += osec->vma; if (ELF_ST_TYPE (sym.st_info) == STT_TLS) { + struct elf_link_hash_table *htab + = elf_hash_table (flinfo->info); + /* STT_TLS symbols are relative to PT_TLS segment base. */ - BFD_ASSERT (elf_hash_table (flinfo->info) - ->tls_sec != NULL); - sym.st_value -= (elf_hash_table (flinfo->info) - ->tls_sec->vma); + if (htab->tls_sec != NULL) + sym.st_value -= htab->tls_sec->vma; + else + sym.st_info + = ELF_ST_INFO (ELF_ST_BIND (sym.st_info), + STT_NOTYPE); } }