From FEDORA_PATCHES Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Alexandra=20H=C3=A1jkov=C3=A1?= Date: Sun, 17 Sep 2023 13:36:13 +0200 Subject: gdb-rhbz2233961-CVE-2022-4806.patch ;; Backport PR29922, SHT_NOBITS section ;; avoids section size sanity check. PR29922, SHT_NOBITS section avoids section size sanity check PR 29922 * dwarf2.c (find_debug_info): Ignore sections without SEC_HAS_CONTENTS. diff --git a/bfd/dwarf2.c b/bfd/dwarf2.c --- a/bfd/dwarf2.c +++ b/bfd/dwarf2.c @@ -4831,16 +4831,19 @@ find_debug_info (bfd *abfd, const struct dwarf_debug_section *debug_sections, { look = debug_sections[debug_info].uncompressed_name; msec = bfd_get_section_by_name (abfd, look); - if (msec != NULL) + /* Testing SEC_HAS_CONTENTS is an anti-fuzzer measure. Of + course debug sections always have contents. */ + if (msec != NULL && (msec->flags & SEC_HAS_CONTENTS) != 0) return msec; look = debug_sections[debug_info].compressed_name; msec = bfd_get_section_by_name (abfd, look); - if (msec != NULL) + if (msec != NULL && (msec->flags & SEC_HAS_CONTENTS) != 0) return msec; for (msec = abfd->sections; msec != NULL; msec = msec->next) - if (startswith (msec->name, GNU_LINKONCE_INFO)) + if ((msec->flags & SEC_HAS_CONTENTS) != 0 + && startswith (msec->name, GNU_LINKONCE_INFO)) return msec; return NULL; @@ -4848,6 +4851,9 @@ find_debug_info (bfd *abfd, const struct dwarf_debug_section *debug_sections, for (msec = after_sec->next; msec != NULL; msec = msec->next) { + if ((msec->flags & SEC_HAS_CONTENTS) == 0) + continue; + look = debug_sections[debug_info].uncompressed_name; if (strcmp (msec->name, look) == 0) return msec;