1From 695c6dfe7e85006b98c8b746f3fd5f913c94ebff Mon Sep 17 00:00:00 2001 2From: Alan Modra <amodra@gmail.com> 3Date: Thu, 21 Jul 2022 09:56:15 +0930 4Subject: [PATCH] PR29370, infinite loop in display_debug_abbrev 5 6The PR29370 testcase is a fuzzed object file with multiple 7.trace_abbrev sections. Multiple .trace_abbrev or .debug_abbrev 8sections are not a violation of the DWARF standard. The DWARF5 9standard even gives an example of multiple .debug_abbrev sections 10contained in groups. Caching and lookup of processed abbrevs thus 11needs to be done by section and offset rather than base and offset. 12(Why base anyway?) Or, since section contents are kept, by a pointer 13into the contents. 14 15 PR 29370 16 * dwarf.c (struct abbrev_list): Replace abbrev_base and 17 abbrev_offset with raw field. 18 (find_abbrev_list_by_abbrev_offset): Delete. 19 (find_abbrev_list_by_raw_abbrev): New function. 20 (process_abbrev_set): Set list->raw and list->next. 21 (find_and_process_abbrev_set): Replace abbrev list lookup with 22 new function. Don't set list abbrev_base, abbrev_offset or next. 23 24Upstream-Status: Backport [https://sourceware.org/git/?p=binutils-gdb.git;a=patch;h=695c6dfe7e85006b98c8b746f3fd5f913c94ebff] 25 26Signed-off-by: Pgowda <pgowda.cve@gmail.com> 27--- 28 binutils/dwarf.c | 19 ++++++------------- 29 1 file changed, 6 insertions(+), 13 deletions(-) 30 31diff --git a/binutils/dwarf.c b/binutils/dwarf.c 32index 2fc352f74c5..99fb3566994 100644 33--- a/binutils/dwarf.c 34+++ b/binutils/dwarf.c 35@@ -856,8 +856,7 @@ typedef struct abbrev_list 36 { 37 abbrev_entry * first_abbrev; 38 abbrev_entry * last_abbrev; 39- dwarf_vma abbrev_base; 40- dwarf_vma abbrev_offset; 41+ unsigned char * raw; 42 struct abbrev_list * next; 43 unsigned char * start_of_next_abbrevs; 44 } 45@@ -946,14 +945,12 @@ free_all_abbrevs (void) 46 } 47 48 static abbrev_list * 49-find_abbrev_list_by_abbrev_offset (dwarf_vma abbrev_base, 50- dwarf_vma abbrev_offset) 51+find_abbrev_list_by_raw_abbrev (unsigned char *raw) 52 { 53 abbrev_list * list; 54 55 for (list = abbrev_lists; list != NULL; list = list->next) 56- if (list->abbrev_base == abbrev_base 57- && list->abbrev_offset == abbrev_offset) 58+ if (list->raw == raw) 59 return list; 60 61 return NULL; 62@@ -1040,6 +1037,7 @@ process_abbrev_set (struct dwarf_section 63 abbrev_list *list = xmalloc (sizeof (*list)); 64 list->first_abbrev = NULL; 65 list->last_abbrev = NULL; 66+ list->raw = start; 67 68 while (start < end) 69 { 70@@ -1055,6 +1053,7 @@ process_abbrev_set (struct dwarf_section 71 the caller. */ 72 if (start == end || entry == 0) 73 { 74+ list->next = NULL; 75 list->start_of_next_abbrevs = start != end ? start : NULL; 76 return list; 77 } 78@@ -1144,16 +1143,10 @@ find_and_process_abbrev_set (struct dwar 79 unsigned char *end = section->start + abbrev_base + abbrev_size; 80 abbrev_list *list = NULL; 81 if (free_list) 82- list = find_abbrev_list_by_abbrev_offset (abbrev_base, abbrev_offset); 83+ list = find_abbrev_list_by_raw_abbrev (start); 84 if (list == NULL) 85 { 86 list = process_abbrev_set (section, start, end); 87- if (list) 88- { 89- list->abbrev_base = abbrev_base; 90- list->abbrev_offset = abbrev_offset; 91- list->next = NULL; 92- } 93 if (free_list) 94 *free_list = list; 95 } 96