| From 695c6dfe7e85006b98c8b746f3fd5f913c94ebff Mon Sep 17 00:00:00 2001 |
| From: Alan Modra <amodra@gmail.com> |
| Date: Thu, 21 Jul 2022 09:56:15 +0930 |
| Subject: [PATCH] PR29370, infinite loop in display_debug_abbrev |
| |
| The PR29370 testcase is a fuzzed object file with multiple |
| .trace_abbrev sections. Multiple .trace_abbrev or .debug_abbrev |
| sections are not a violation of the DWARF standard. The DWARF5 |
| standard even gives an example of multiple .debug_abbrev sections |
| contained in groups. Caching and lookup of processed abbrevs thus |
| needs to be done by section and offset rather than base and offset. |
| (Why base anyway?) Or, since section contents are kept, by a pointer |
| into the contents. |
| |
| PR 29370 |
| * dwarf.c (struct abbrev_list): Replace abbrev_base and |
| abbrev_offset with raw field. |
| (find_abbrev_list_by_abbrev_offset): Delete. |
| (find_abbrev_list_by_raw_abbrev): New function. |
| (process_abbrev_set): Set list->raw and list->next. |
| (find_and_process_abbrev_set): Replace abbrev list lookup with |
| new function. Don't set list abbrev_base, abbrev_offset or next. |
| |
| Upstream-Status: Backport [https://sourceware.org/git/?p=binutils-gdb.git;a=patch;h=695c6dfe7e85006b98c8b746f3fd5f913c94ebff] |
| |
| Signed-off-by: Pgowda <pgowda.cve@gmail.com> |
| --- |
| binutils/dwarf.c | 19 ++++++------------- |
| 1 file changed, 6 insertions(+), 13 deletions(-) |
| |
| diff --git a/binutils/dwarf.c b/binutils/dwarf.c |
| index 2fc352f74c5..99fb3566994 100644 |
| --- a/binutils/dwarf.c |
| +++ b/binutils/dwarf.c |
| @@ -856,8 +856,7 @@ typedef struct abbrev_list |
| { |
| abbrev_entry * first_abbrev; |
| abbrev_entry * last_abbrev; |
| - dwarf_vma abbrev_base; |
| - dwarf_vma abbrev_offset; |
| + unsigned char * raw; |
| struct abbrev_list * next; |
| unsigned char * start_of_next_abbrevs; |
| } |
| @@ -946,14 +945,12 @@ free_all_abbrevs (void) |
| } |
| |
| static abbrev_list * |
| -find_abbrev_list_by_abbrev_offset (dwarf_vma abbrev_base, |
| - dwarf_vma abbrev_offset) |
| +find_abbrev_list_by_raw_abbrev (unsigned char *raw) |
| { |
| abbrev_list * list; |
| |
| for (list = abbrev_lists; list != NULL; list = list->next) |
| - if (list->abbrev_base == abbrev_base |
| - && list->abbrev_offset == abbrev_offset) |
| + if (list->raw == raw) |
| return list; |
| |
| return NULL; |
| @@ -1040,6 +1037,7 @@ process_abbrev_set (struct dwarf_section |
| abbrev_list *list = xmalloc (sizeof (*list)); |
| list->first_abbrev = NULL; |
| list->last_abbrev = NULL; |
| + list->raw = start; |
| |
| while (start < end) |
| { |
| @@ -1055,6 +1053,7 @@ process_abbrev_set (struct dwarf_section |
| the caller. */ |
| if (start == end || entry == 0) |
| { |
| + list->next = NULL; |
| list->start_of_next_abbrevs = start != end ? start : NULL; |
| return list; |
| } |
| @@ -1144,16 +1143,10 @@ find_and_process_abbrev_set (struct dwar |
| unsigned char *end = section->start + abbrev_base + abbrev_size; |
| abbrev_list *list = NULL; |
| if (free_list) |
| - list = find_abbrev_list_by_abbrev_offset (abbrev_base, abbrev_offset); |
| + list = find_abbrev_list_by_raw_abbrev (start); |
| if (list == NULL) |
| { |
| list = process_abbrev_set (section, start, end); |
| - if (list) |
| - { |
| - list->abbrev_base = abbrev_base; |
| - list->abbrev_offset = abbrev_offset; |
| - list->next = NULL; |
| - } |
| if (free_list) |
| *free_list = list; |
| } |