blob: b240a3f99404aa8eb9fe4d2d4ae0e5a49dfc93c5 [file] [log] [blame]
Brad Bishop1a4b7ee2018-12-16 17:11:34 -08001From 0930cb3021b8078b34cf216e79eb8608d017864f Mon Sep 17 00:00:00 2001
2From: Alan Modra <amodra@gmail.com>
3Date: Sat, 13 Oct 2018 22:03:02 +1030
4Subject: [PATCH] _bfd_clear_contents bounds checking
5
6This PR shows a fuzzed binary triggering a segfault via a bad
7relocation in .debug_line. It turns out that unlike normal
8relocations applied to a section, the linker applies those with
9symbols from discarded sections via _bfd_clear_contents without
10checking that the relocation is within the section bounds. The same
11thing now happens when reading debug sections since commit
12a4cd947aca23, 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
32Upstream-Status: Backport
33CVE: CVE-2018-18605
34Signed-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
52diff --git a/bfd/ChangeLog b/bfd/ChangeLog
53index 68c1ff665b..e9696ee314 100644
54--- a/bfd/ChangeLog
55+++ b/bfd/ChangeLog
56@@ -1,3 +1,23 @@
57+2018-10-13 Alan Modra <amodra@gmail.com>
58+
59+ PR 23770
60+ PR 23425
61+ * reloc.c (_bfd_clear_contents): Replace "location" param with
62+ "buf" and "off". Bounds check "off". Return status.
63+ * cofflink.c (_bfd_coff_generic_relocate_section): Update
64+ _bfd_clear_contents call.
65+ * elf-bfd.h (RELOC_AGAINST_DISCARDED_SECTION): Likewise.
66+ * elf32-arc.c (elf_arc_relocate_section): Likewise.
67+ * elf32-i386.c (elf_i386_relocate_section): Likewise.
68+ * elf32-metag.c (metag_final_link_relocate): Likewise.
69+ * elf32-nds32.c (nds32_elf_get_relocated_section_contents): Likewise.
70+ * elf32-ppc.c (ppc_elf_relocate_section): Likewise.
71+ * elf32-visium.c (visium_elf_relocate_section): Likewise.
72+ * elf64-ppc.c (ppc64_elf_relocate_section): Likewise.
73+ * elf64-x86-64.c *(elf_x86_64_relocate_section): Likewise.
74+ * libbfd-in.h (_bfd_clear_contents): Update prototype.
75+ * libbfd.h: Regenerate.
76+
77 2018-09-20 Alan Modra <amodra@gmail.com>
78
79 PR 23685
80diff --git a/bfd/cofflink.c b/bfd/cofflink.c
81index 2f73f72e31..b7ea69b7f9 100644
82--- a/bfd/cofflink.c
83+++ b/bfd/cofflink.c
84@@ -3080,7 +3080,7 @@ _bfd_coff_generic_relocate_section (bfd *output_bfd,
85 if (sec != NULL && discarded_section (sec))
86 {
87 _bfd_clear_contents (howto, input_bfd, input_section,
88- contents + (rel->r_vaddr - input_section->vma));
89+ contents, rel->r_vaddr - input_section->vma);
90 continue;
91 }
92
93diff --git a/bfd/elf-bfd.h b/bfd/elf-bfd.h
94index cf256f70e0..3374f411f9 100644
95--- a/bfd/elf-bfd.h
96+++ b/bfd/elf-bfd.h
97@@ -2811,7 +2811,7 @@ extern asection _bfd_elf_large_com_section;
98 { \
99 int i_; \
100 _bfd_clear_contents (howto, input_bfd, input_section, \
101- contents + rel[index].r_offset); \
102+ contents, rel[index].r_offset); \
103 \
104 if (bfd_link_relocatable (info) \
105 && (input_section->flags & SEC_DEBUGGING)) \
106diff --git a/bfd/elf32-arc.c b/bfd/elf32-arc.c
107index 7a1b3042ae..30f47a5b22 100644
108--- a/bfd/elf32-arc.c
109+++ b/bfd/elf32-arc.c
110@@ -1549,7 +1549,7 @@ elf_arc_relocate_section (bfd * output_bfd,
111 if (sec != NULL && discarded_section (sec))
112 {
113 _bfd_clear_contents (howto, input_bfd, input_section,
114- contents + rel->r_offset);
115+ contents, rel->r_offset);
116 rel->r_info = 0;
117 rel->r_addend = 0;
118
119diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c
120index 49797dcbfa..177471777d 100644
121--- a/bfd/elf32-i386.c
122+++ b/bfd/elf32-i386.c
123@@ -2197,7 +2197,7 @@ elf_i386_relocate_section (bfd *output_bfd,
124 if (sec != NULL && discarded_section (sec))
125 {
126 _bfd_clear_contents (howto, input_bfd, input_section,
127- contents + rel->r_offset);
128+ contents, rel->r_offset);
129 wrel->r_offset = rel->r_offset;
130 wrel->r_info = 0;
131 wrel->r_addend = 0;
132diff --git a/bfd/elf32-metag.c b/bfd/elf32-metag.c
133index efe95bddff..7f96246e5d 100644
134--- a/bfd/elf32-metag.c
135+++ b/bfd/elf32-metag.c
136@@ -1396,7 +1396,7 @@ metag_final_link_relocate (reloc_howto_type *howto,
137 rel, relend, howto, contents) \
138 { \
139 _bfd_clear_contents (howto, input_bfd, input_section, \
140- contents + rel->r_offset); \
141+ contents, rel->r_offset); \
142 \
143 if (bfd_link_relocatable (info) \
144 && (input_section->flags & SEC_DEBUGGING)) \
145diff --git a/bfd/elf32-nds32.c b/bfd/elf32-nds32.c
146index 0d86e5b865..184cf320f7 100644
147--- a/bfd/elf32-nds32.c
148+++ b/bfd/elf32-nds32.c
149@@ -12582,14 +12582,14 @@ nds32_elf_get_relocated_section_contents (bfd *abfd,
150 symbol = *(*parent)->sym_ptr_ptr;
151 if (symbol->section && discarded_section (symbol->section))
152 {
153- bfd_byte *p;
154+ bfd_vma off;
155 static reloc_howto_type none_howto
156 = HOWTO (0, 0, 0, 0, FALSE, 0, complain_overflow_dont, NULL,
157 "unused", FALSE, 0, 0, FALSE);
158
159- p = data + (*parent)->address * bfd_octets_per_byte (input_bfd);
160- _bfd_clear_contents ((*parent)->howto, input_bfd, input_section,
161- p);
162+ off = (*parent)->address * bfd_octets_per_byte (input_bfd);
163+ _bfd_clear_contents ((*parent)->howto, input_bfd,
164+ input_section, data, off);
165 (*parent)->sym_ptr_ptr = bfd_abs_section_ptr->symbol_ptr_ptr;
166 (*parent)->addend = 0;
167 (*parent)->howto = &none_howto;
168diff --git a/bfd/elf32-ppc.c b/bfd/elf32-ppc.c
169index 61f70de12e..c31e26efd7 100644
170--- a/bfd/elf32-ppc.c
171+++ b/bfd/elf32-ppc.c
172@@ -8232,7 +8232,7 @@ ppc_elf_relocate_section (bfd *output_bfd,
173 howto = ppc_elf_howto_table[r_type];
174
175 _bfd_clear_contents (howto, input_bfd, input_section,
176- contents + rel->r_offset);
177+ contents, rel->r_offset);
178 wrel->r_offset = rel->r_offset;
179 wrel->r_info = 0;
180 wrel->r_addend = 0;
181diff --git a/bfd/elf32-visium.c b/bfd/elf32-visium.c
182index e8f1c4c9e4..961366cd87 100644
183--- a/bfd/elf32-visium.c
184+++ b/bfd/elf32-visium.c
185@@ -621,7 +621,7 @@ visium_elf_relocate_section (bfd *output_bfd,
186 or sections discarded by a linker script, we just want the
187 section contents zeroed. Avoid any special processing. */
188 _bfd_clear_contents (howto, input_bfd, input_section,
189- contents + rel->r_offset);
190+ contents, rel->r_offset);
191
192 rel->r_info = 0;
193 rel->r_addend = 0;
194diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
195index eadde17615..7c3534ac65 100644
196--- a/bfd/elf64-ppc.c
197+++ b/bfd/elf64-ppc.c
198@@ -14073,7 +14073,7 @@ ppc64_elf_relocate_section (bfd *output_bfd,
199 {
200 _bfd_clear_contents (ppc64_elf_howto_table[r_type],
201 input_bfd, input_section,
202- contents + rel->r_offset);
203+ contents, rel->r_offset);
204 wrel->r_offset = rel->r_offset;
205 wrel->r_info = 0;
206 wrel->r_addend = 0;
207diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
208index c3a6c31ed2..4dcab43478 100644
209--- a/bfd/elf64-x86-64.c
210+++ b/bfd/elf64-x86-64.c
211@@ -2490,7 +2490,7 @@ elf_x86_64_relocate_section (bfd *output_bfd,
212 if (sec != NULL && discarded_section (sec))
213 {
214 _bfd_clear_contents (howto, input_bfd, input_section,
215- contents + rel->r_offset);
216+ contents, rel->r_offset);
217 wrel->r_offset = rel->r_offset;
218 wrel->r_info = 0;
219 wrel->r_addend = 0;
220diff --git a/bfd/libbfd-in.h b/bfd/libbfd-in.h
221index e53b255dad..f6d9565f03 100644
222--- a/bfd/libbfd-in.h
223+++ b/bfd/libbfd-in.h
224@@ -696,8 +696,8 @@ extern bfd_reloc_status_type _bfd_relocate_contents
225 (reloc_howto_type *, bfd *, bfd_vma, bfd_byte *) ATTRIBUTE_HIDDEN;
226
227 /* Clear a given location using a given howto. */
228-extern void _bfd_clear_contents
229- (reloc_howto_type *, bfd *, asection *, bfd_byte *) ATTRIBUTE_HIDDEN;
230+extern bfd_reloc_status_type _bfd_clear_contents
231+ (reloc_howto_type *, bfd *, asection *, bfd_byte *, bfd_vma) ATTRIBUTE_HIDDEN;
232
233 /* Link stabs in sections in the first pass. */
234
235diff --git a/bfd/libbfd.h b/bfd/libbfd.h
236index a8851c8026..1189e63358 100644
237--- a/bfd/libbfd.h
238+++ b/bfd/libbfd.h
239@@ -701,8 +701,8 @@ extern bfd_reloc_status_type _bfd_relocate_contents
240 (reloc_howto_type *, bfd *, bfd_vma, bfd_byte *) ATTRIBUTE_HIDDEN;
241
242 /* Clear a given location using a given howto. */
243-extern void _bfd_clear_contents
244- (reloc_howto_type *, bfd *, asection *, bfd_byte *) ATTRIBUTE_HIDDEN;
245+extern bfd_reloc_status_type _bfd_clear_contents
246+ (reloc_howto_type *, bfd *, asection *, bfd_byte *, bfd_vma) ATTRIBUTE_HIDDEN;
247
248 /* Link stabs in sections in the first pass. */
249
250diff --git a/bfd/reloc.c b/bfd/reloc.c
251index 8dbb8896d3..1686780669 100644
252--- a/bfd/reloc.c
253+++ b/bfd/reloc.c
254@@ -1613,16 +1613,22 @@ _bfd_relocate_contents (reloc_howto_type *howto,
255 relocations against discarded symbols, to make ignorable debug or unwind
256 information more obvious. */
257
258-void
259+bfd_reloc_status_type
260 _bfd_clear_contents (reloc_howto_type *howto,
261 bfd *input_bfd,
262 asection *input_section,
263- bfd_byte *location)
264+ bfd_byte *buf,
265+ bfd_vma off)
266 {
267 int size;
268 bfd_vma x = 0;
269+ bfd_byte *location;
270+
271+ if (!bfd_reloc_offset_in_range (howto, input_bfd, input_section, off))
272+ return bfd_reloc_outofrange;
273
274 /* Get the value we are going to relocate. */
275+ location = buf + off;
276 size = bfd_get_reloc_size (howto);
277 switch (size)
278 {
279@@ -1687,6 +1693,7 @@ _bfd_clear_contents (reloc_howto_type *howto,
280 #endif
281 break;
282 }
283+ return bfd_reloc_ok;
284 }
285
286 /*
287@@ -8275,14 +8282,14 @@ bfd_generic_get_relocated_section_contents (bfd *abfd,
288
289 if (symbol->section && discarded_section (symbol->section))
290 {
291- bfd_byte *p;
292+ bfd_vma off;
293 static reloc_howto_type none_howto
294 = HOWTO (0, 0, 0, 0, FALSE, 0, complain_overflow_dont, NULL,
295 "unused", FALSE, 0, 0, FALSE);
296
297- p = data + (*parent)->address * bfd_octets_per_byte (input_bfd);
298- _bfd_clear_contents ((*parent)->howto, input_bfd, input_section,
299- p);
300+ off = (*parent)->address * bfd_octets_per_byte (input_bfd);
301+ _bfd_clear_contents ((*parent)->howto, input_bfd,
302+ input_section, data, off);
303 (*parent)->sym_ptr_ptr = bfd_abs_section_ptr->symbol_ptr_ptr;
304 (*parent)->addend = 0;
305 (*parent)->howto = &none_howto;
306--
3072.13.3
308