Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 1 | From 0930cb3021b8078b34cf216e79eb8608d017864f Mon Sep 17 00:00:00 2001 |
| 2 | From: Alan Modra <amodra@gmail.com> |
| 3 | Date: Sat, 13 Oct 2018 22:03:02 +1030 |
| 4 | Subject: [PATCH] _bfd_clear_contents bounds checking |
| 5 | |
| 6 | This PR shows a fuzzed binary triggering a segfault via a bad |
| 7 | relocation in .debug_line. It turns out that unlike normal |
| 8 | relocations applied to a section, the linker applies those with |
| 9 | symbols from discarded sections via _bfd_clear_contents without |
| 10 | checking that the relocation is within the section bounds. The same |
| 11 | thing now happens when reading debug sections since commit |
| 12 | a4cd947aca23, the PR23425 fix. |
| 13 | |
| 14 | PR 23770 |
| 15 | PR 23425 |
| 16 | * reloc.c (_bfd_clear_contents): Replace "location" param with |
| 17 | "buf" and "off". Bounds check "off". Return status. |
| 18 | * cofflink.c (_bfd_coff_generic_relocate_section): Update |
| 19 | _bfd_clear_contents call. |
| 20 | * elf-bfd.h (RELOC_AGAINST_DISCARDED_SECTION): Likewise. |
| 21 | * elf32-arc.c (elf_arc_relocate_section): Likewise. |
| 22 | * elf32-i386.c (elf_i386_relocate_section): Likewise. |
| 23 | * elf32-metag.c (metag_final_link_relocate): Likewise. |
| 24 | * elf32-nds32.c (nds32_elf_get_relocated_section_contents): Likewise. |
| 25 | * elf32-ppc.c (ppc_elf_relocate_section): Likewise. |
| 26 | * elf32-visium.c (visium_elf_relocate_section): Likewise. |
| 27 | * elf64-ppc.c (ppc64_elf_relocate_section): Likewise. |
| 28 | * elf64-x86-64.c *(elf_x86_64_relocate_section): Likewise. |
| 29 | * libbfd-in.h (_bfd_clear_contents): Update prototype. |
| 30 | * libbfd.h: Regenerate. |
| 31 | |
| 32 | Upstream-Status: Backport |
| 33 | CVE: CVE-2018-18605 |
| 34 | Signed-off-by: Zhixiong Chi <zhixiong.chi@windriver.com> |
| 35 | --- |
| 36 | bfd/ChangeLog | 20 ++++++++++++++++++++ |
| 37 | bfd/cofflink.c | 2 +- |
| 38 | bfd/elf-bfd.h | 2 +- |
| 39 | bfd/elf32-arc.c | 2 +- |
| 40 | bfd/elf32-i386.c | 2 +- |
| 41 | bfd/elf32-metag.c | 2 +- |
| 42 | bfd/elf32-nds32.c | 8 ++++---- |
| 43 | bfd/elf32-ppc.c | 2 +- |
| 44 | bfd/elf32-visium.c | 2 +- |
| 45 | bfd/elf64-ppc.c | 2 +- |
| 46 | bfd/elf64-x86-64.c | 2 +- |
| 47 | bfd/libbfd-in.h | 4 ++-- |
| 48 | bfd/libbfd.h | 4 ++-- |
| 49 | bfd/reloc.c | 19 +++++++++++++------ |
| 50 | 14 files changed, 50 insertions(+), 23 deletions(-) |
| 51 | |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 52 | --- a/bfd/cofflink.c |
| 53 | +++ b/bfd/cofflink.c |
Brad Bishop | 977dc1a | 2019-02-06 16:01:43 -0500 | [diff] [blame] | 54 | @@ -3080,7 +3080,7 @@ _bfd_coff_generic_relocate_section (bfd |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 55 | if (sec != NULL && discarded_section (sec)) |
| 56 | { |
| 57 | _bfd_clear_contents (howto, input_bfd, input_section, |
| 58 | - contents + (rel->r_vaddr - input_section->vma)); |
| 59 | + contents, rel->r_vaddr - input_section->vma); |
| 60 | continue; |
| 61 | } |
| 62 | |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 63 | --- a/bfd/elf-bfd.h |
| 64 | +++ b/bfd/elf-bfd.h |
Brad Bishop | 977dc1a | 2019-02-06 16:01:43 -0500 | [diff] [blame] | 65 | @@ -2811,7 +2811,7 @@ extern asection _bfd_elf_large_com_secti |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 66 | { \ |
| 67 | int i_; \ |
| 68 | _bfd_clear_contents (howto, input_bfd, input_section, \ |
| 69 | - contents + rel[index].r_offset); \ |
| 70 | + contents, rel[index].r_offset); \ |
| 71 | \ |
| 72 | if (bfd_link_relocatable (info) \ |
| 73 | && (input_section->flags & SEC_DEBUGGING)) \ |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 74 | --- a/bfd/elf32-arc.c |
| 75 | +++ b/bfd/elf32-arc.c |
Brad Bishop | 977dc1a | 2019-02-06 16:01:43 -0500 | [diff] [blame] | 76 | @@ -1552,7 +1552,7 @@ elf_arc_relocate_section (bfd * outp |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 77 | if (sec != NULL && discarded_section (sec)) |
| 78 | { |
| 79 | _bfd_clear_contents (howto, input_bfd, input_section, |
| 80 | - contents + rel->r_offset); |
| 81 | + contents, rel->r_offset); |
| 82 | rel->r_info = 0; |
| 83 | rel->r_addend = 0; |
| 84 | |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 85 | --- a/bfd/elf32-i386.c |
| 86 | +++ b/bfd/elf32-i386.c |
Brad Bishop | 977dc1a | 2019-02-06 16:01:43 -0500 | [diff] [blame] | 87 | @@ -2197,7 +2197,7 @@ elf_i386_relocate_section (bfd *output_b |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 88 | if (sec != NULL && discarded_section (sec)) |
| 89 | { |
| 90 | _bfd_clear_contents (howto, input_bfd, input_section, |
| 91 | - contents + rel->r_offset); |
| 92 | + contents, rel->r_offset); |
| 93 | wrel->r_offset = rel->r_offset; |
| 94 | wrel->r_info = 0; |
| 95 | wrel->r_addend = 0; |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 96 | --- a/bfd/elf32-metag.c |
| 97 | +++ b/bfd/elf32-metag.c |
Brad Bishop | 977dc1a | 2019-02-06 16:01:43 -0500 | [diff] [blame] | 98 | @@ -1396,7 +1396,7 @@ metag_final_link_relocate (reloc_howto_t |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 99 | rel, relend, howto, contents) \ |
| 100 | { \ |
| 101 | _bfd_clear_contents (howto, input_bfd, input_section, \ |
| 102 | - contents + rel->r_offset); \ |
| 103 | + contents, rel->r_offset); \ |
| 104 | \ |
| 105 | if (bfd_link_relocatable (info) \ |
| 106 | && (input_section->flags & SEC_DEBUGGING)) \ |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 107 | --- a/bfd/elf32-nds32.c |
| 108 | +++ b/bfd/elf32-nds32.c |
Brad Bishop | 977dc1a | 2019-02-06 16:01:43 -0500 | [diff] [blame] | 109 | @@ -12582,14 +12582,14 @@ nds32_elf_get_relocated_section_contents |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 110 | symbol = *(*parent)->sym_ptr_ptr; |
| 111 | if (symbol->section && discarded_section (symbol->section)) |
| 112 | { |
| 113 | - bfd_byte *p; |
| 114 | + bfd_vma off; |
| 115 | static reloc_howto_type none_howto |
| 116 | = HOWTO (0, 0, 0, 0, FALSE, 0, complain_overflow_dont, NULL, |
| 117 | "unused", FALSE, 0, 0, FALSE); |
| 118 | |
| 119 | - p = data + (*parent)->address * bfd_octets_per_byte (input_bfd); |
| 120 | - _bfd_clear_contents ((*parent)->howto, input_bfd, input_section, |
| 121 | - p); |
| 122 | + off = (*parent)->address * bfd_octets_per_byte (input_bfd); |
| 123 | + _bfd_clear_contents ((*parent)->howto, input_bfd, |
| 124 | + input_section, data, off); |
| 125 | (*parent)->sym_ptr_ptr = bfd_abs_section_ptr->symbol_ptr_ptr; |
| 126 | (*parent)->addend = 0; |
| 127 | (*parent)->howto = &none_howto; |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 128 | --- a/bfd/elf32-ppc.c |
| 129 | +++ b/bfd/elf32-ppc.c |
Brad Bishop | 977dc1a | 2019-02-06 16:01:43 -0500 | [diff] [blame] | 130 | @@ -8232,7 +8232,7 @@ ppc_elf_relocate_section (bfd *output_bf |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 131 | howto = ppc_elf_howto_table[r_type]; |
| 132 | |
| 133 | _bfd_clear_contents (howto, input_bfd, input_section, |
| 134 | - contents + rel->r_offset); |
| 135 | + contents, rel->r_offset); |
| 136 | wrel->r_offset = rel->r_offset; |
| 137 | wrel->r_info = 0; |
| 138 | wrel->r_addend = 0; |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 139 | --- a/bfd/elf32-visium.c |
| 140 | +++ b/bfd/elf32-visium.c |
Brad Bishop | 977dc1a | 2019-02-06 16:01:43 -0500 | [diff] [blame] | 141 | @@ -621,7 +621,7 @@ visium_elf_relocate_section (bfd *output |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 142 | or sections discarded by a linker script, we just want the |
| 143 | section contents zeroed. Avoid any special processing. */ |
| 144 | _bfd_clear_contents (howto, input_bfd, input_section, |
| 145 | - contents + rel->r_offset); |
| 146 | + contents, rel->r_offset); |
| 147 | |
| 148 | rel->r_info = 0; |
| 149 | rel->r_addend = 0; |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 150 | --- a/bfd/elf64-ppc.c |
| 151 | +++ b/bfd/elf64-ppc.c |
Brad Bishop | 977dc1a | 2019-02-06 16:01:43 -0500 | [diff] [blame] | 152 | @@ -14074,7 +14074,7 @@ ppc64_elf_relocate_section (bfd *output_ |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 153 | { |
| 154 | _bfd_clear_contents (ppc64_elf_howto_table[r_type], |
| 155 | input_bfd, input_section, |
| 156 | - contents + rel->r_offset); |
| 157 | + contents, rel->r_offset); |
| 158 | wrel->r_offset = rel->r_offset; |
| 159 | wrel->r_info = 0; |
| 160 | wrel->r_addend = 0; |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 161 | --- a/bfd/elf64-x86-64.c |
| 162 | +++ b/bfd/elf64-x86-64.c |
Brad Bishop | 977dc1a | 2019-02-06 16:01:43 -0500 | [diff] [blame] | 163 | @@ -2490,7 +2490,7 @@ elf_x86_64_relocate_section (bfd *output |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 164 | if (sec != NULL && discarded_section (sec)) |
| 165 | { |
| 166 | _bfd_clear_contents (howto, input_bfd, input_section, |
| 167 | - contents + rel->r_offset); |
| 168 | + contents, rel->r_offset); |
| 169 | wrel->r_offset = rel->r_offset; |
| 170 | wrel->r_info = 0; |
| 171 | wrel->r_addend = 0; |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 172 | --- a/bfd/libbfd-in.h |
| 173 | +++ b/bfd/libbfd-in.h |
Brad Bishop | 977dc1a | 2019-02-06 16:01:43 -0500 | [diff] [blame] | 174 | @@ -696,8 +696,8 @@ extern bfd_reloc_status_type _bfd_reloca |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 175 | (reloc_howto_type *, bfd *, bfd_vma, bfd_byte *) ATTRIBUTE_HIDDEN; |
| 176 | |
| 177 | /* Clear a given location using a given howto. */ |
| 178 | -extern void _bfd_clear_contents |
| 179 | - (reloc_howto_type *, bfd *, asection *, bfd_byte *) ATTRIBUTE_HIDDEN; |
| 180 | +extern bfd_reloc_status_type _bfd_clear_contents |
| 181 | + (reloc_howto_type *, bfd *, asection *, bfd_byte *, bfd_vma) ATTRIBUTE_HIDDEN; |
| 182 | |
| 183 | /* Link stabs in sections in the first pass. */ |
| 184 | |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 185 | --- a/bfd/libbfd.h |
| 186 | +++ b/bfd/libbfd.h |
Brad Bishop | 977dc1a | 2019-02-06 16:01:43 -0500 | [diff] [blame] | 187 | @@ -701,8 +701,8 @@ extern bfd_reloc_status_type _bfd_reloca |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 188 | (reloc_howto_type *, bfd *, bfd_vma, bfd_byte *) ATTRIBUTE_HIDDEN; |
| 189 | |
| 190 | /* Clear a given location using a given howto. */ |
| 191 | -extern void _bfd_clear_contents |
| 192 | - (reloc_howto_type *, bfd *, asection *, bfd_byte *) ATTRIBUTE_HIDDEN; |
| 193 | +extern bfd_reloc_status_type _bfd_clear_contents |
| 194 | + (reloc_howto_type *, bfd *, asection *, bfd_byte *, bfd_vma) ATTRIBUTE_HIDDEN; |
| 195 | |
| 196 | /* Link stabs in sections in the first pass. */ |
| 197 | |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 198 | --- a/bfd/reloc.c |
| 199 | +++ b/bfd/reloc.c |
Brad Bishop | 977dc1a | 2019-02-06 16:01:43 -0500 | [diff] [blame] | 200 | @@ -1613,16 +1613,22 @@ _bfd_relocate_contents (reloc_howto_type |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 201 | relocations against discarded symbols, to make ignorable debug or unwind |
| 202 | information more obvious. */ |
| 203 | |
| 204 | -void |
| 205 | +bfd_reloc_status_type |
| 206 | _bfd_clear_contents (reloc_howto_type *howto, |
| 207 | bfd *input_bfd, |
| 208 | asection *input_section, |
| 209 | - bfd_byte *location) |
| 210 | + bfd_byte *buf, |
| 211 | + bfd_vma off) |
| 212 | { |
| 213 | int size; |
| 214 | bfd_vma x = 0; |
| 215 | + bfd_byte *location; |
| 216 | + |
| 217 | + if (!bfd_reloc_offset_in_range (howto, input_bfd, input_section, off)) |
| 218 | + return bfd_reloc_outofrange; |
| 219 | |
| 220 | /* Get the value we are going to relocate. */ |
| 221 | + location = buf + off; |
| 222 | size = bfd_get_reloc_size (howto); |
| 223 | switch (size) |
| 224 | { |
Brad Bishop | 977dc1a | 2019-02-06 16:01:43 -0500 | [diff] [blame] | 225 | @@ -1681,6 +1687,7 @@ _bfd_clear_contents (reloc_howto_type *h |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 226 | #endif |
| 227 | break; |
| 228 | } |
| 229 | + return bfd_reloc_ok; |
| 230 | } |
| 231 | |
| 232 | /* |
Brad Bishop | 977dc1a | 2019-02-06 16:01:43 -0500 | [diff] [blame] | 233 | @@ -8268,14 +8275,14 @@ bfd_generic_get_relocated_section_conten |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 234 | |
| 235 | if (symbol->section && discarded_section (symbol->section)) |
| 236 | { |
| 237 | - bfd_byte *p; |
| 238 | + bfd_vma off; |
| 239 | static reloc_howto_type none_howto |
| 240 | = HOWTO (0, 0, 0, 0, FALSE, 0, complain_overflow_dont, NULL, |
| 241 | "unused", FALSE, 0, 0, FALSE); |
| 242 | |
| 243 | - p = data + (*parent)->address * bfd_octets_per_byte (input_bfd); |
| 244 | - _bfd_clear_contents ((*parent)->howto, input_bfd, input_section, |
| 245 | - p); |
| 246 | + off = (*parent)->address * bfd_octets_per_byte (input_bfd); |
| 247 | + _bfd_clear_contents ((*parent)->howto, input_bfd, |
| 248 | + input_section, data, off); |
| 249 | (*parent)->sym_ptr_ptr = bfd_abs_section_ptr->symbol_ptr_ptr; |
| 250 | (*parent)->addend = 0; |
| 251 | (*parent)->howto = &none_howto; |