[PATCH][Binutils][2_42] Backport fixes for (PR 32636, 32641, 32643, 32644)
sunilkumar.dora@windriver.com
sunilkumar.dora@windriver.com
Tue Apr 29 14:52:37 GMT 2025
From: Nick Clifton <nickc@redhat.com>
This commit backports the following fixes from master to the 2.42 branch:
Cherry pick from master:
1. PR 32636 - Fix heap-buffer-overflow in _bfd_elf_gc_mark_rsec when processing
corrupt ELF input with long paths and --gc-sections. Prevents illegal memory
access when indexing sym_hashes array.
(https://sourceware.org/bugzilla/show_bug.cgi?id=32636)
2. PR 32641 - Fix SEGV in _bfd_x86_elf_check_relocs when processing malformed
relocations with -w option. Adds validation for relocation/symbol integrity.
(https://sourceware.org/bugzilla/show_bug.cgi?id=32641)
3. PR 32643 - Fix SEGV in _bfd_elf_gc_mark_rsec with --gc-sections on corrupt
input. Strengthens relocation processing checks.
(https://sourceware.org/bugzilla/show_bug.cgi?id=32643)
4. PR 32644 - Fix SEGV in bfd_elf_reloc_symbol_deleted_p with combination of
--no-undefined, --orphan-handling and -w options. Adds missing validation.
(https://sourceware.org/bugzilla/show_bug.cgi?id=32644)
Signed-off-by: Sunil Dora <sunilkumar.dora@windriver.com>
---
bfd/elf-bfd.h | 3 +
bfd/elf64-x86-64.c | 10 +-
bfd/elflink.c | 270 ++++++++++++++++++++++++---------------------
bfd/elfxx-x86.c | 20 ++--
4 files changed, 162 insertions(+), 141 deletions(-)
diff --git a/bfd/elf-bfd.h b/bfd/elf-bfd.h
index 3ed22fa6c52..07add7d0302 100644
--- a/bfd/elf-bfd.h
+++ b/bfd/elf-bfd.h
@@ -3126,6 +3126,9 @@ extern bool _bfd_elf_maybe_set_textrel
extern bool _bfd_elf_add_dynamic_tags
(bfd *, struct bfd_link_info *, bool);
+extern struct elf_link_hash_entry * _bfd_elf_get_link_hash_entry
+ (struct elf_link_hash_entry **, unsigned int, Elf_Internal_Shdr *);
+
/* Large common section. */
extern asection _bfd_elf_large_com_section;
diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index 2ed120af780..74ff749c091 100644
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -1665,7 +1665,7 @@ elf_x86_64_convert_load_reloc (bfd *abfd,
bool to_reloc_pc32;
bool abs_symbol;
bool local_ref;
- asection *tsec;
+ asection *tsec = NULL;
bfd_signed_vma raddend;
unsigned int opcode;
unsigned int modrm;
@@ -1831,6 +1831,9 @@ elf_x86_64_convert_load_reloc (bfd *abfd,
return true;
}
+ if (tsec == NULL)
+ return false;
+
/* Don't convert GOTPCREL relocation against large section. */
if (elf_section_data (tsec) != NULL
&& (elf_section_flags (tsec) & SHF_X86_64_LARGE) != 0)
@@ -2127,10 +2130,7 @@ elf_x86_64_scan_relocs (bfd *abfd, struct bfd_link_info *info,
else
{
isym = NULL;
- h = sym_hashes[r_symndx - symtab_hdr->sh_info];
- while (h->root.type == bfd_link_hash_indirect
- || h->root.type == bfd_link_hash_warning)
- h = (struct elf_link_hash_entry *) h->root.u.i.link;
+ h = _bfd_elf_get_link_hash_entry (sym_hashes, r_symndx, symtab_hdr);
}
/* Check invalid x32 relocations. */
diff --git a/bfd/elflink.c b/bfd/elflink.c
index 0fd06d11c24..97555b166d6 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -49,22 +49,60 @@ struct elf_info_failed
static bool _bfd_elf_fix_symbol_flags
(struct elf_link_hash_entry *, struct elf_info_failed *);
-asection *
-_bfd_elf_section_for_symbol (struct elf_reloc_cookie *cookie,
- unsigned long r_symndx,
- bool discard)
+static struct elf_link_hash_entry *
+get_link_hash_entry (struct elf_link_hash_entry ** sym_hashes,
+ unsigned int symndx,
+ unsigned int ext_sym_start)
+{
+ if (sym_hashes == NULL
+ /* Guard against corrupt input. See PR 32636 for an example. */
+ || symndx < ext_sym_start)
+ return NULL;
+
+ struct elf_link_hash_entry *h = sym_hashes[symndx - ext_sym_start];
+
+ /* The hash might be empty. See PR 32641 for an example of this. */
+ if (h == NULL)
+ return NULL;
+
+ while (h->root.type == bfd_link_hash_indirect
+ || h->root.type == bfd_link_hash_warning)
+ h = (struct elf_link_hash_entry *) h->root.u.i.link;
+
+ return h;
+}
+
+struct elf_link_hash_entry *
+_bfd_elf_get_link_hash_entry (struct elf_link_hash_entry ** sym_hashes,
+ unsigned int symndx,
+ Elf_Internal_Shdr * symtab_hdr)
{
- if (r_symndx >= cookie->locsymcount
- || ELF_ST_BIND (cookie->locsyms[r_symndx].st_info) != STB_LOCAL)
- {
- struct elf_link_hash_entry *h;
+ if (symtab_hdr == NULL)
+ return NULL;
+ return get_link_hash_entry (sym_hashes, symndx, symtab_hdr->sh_info);
+}
- h = cookie->sym_hashes[r_symndx - cookie->extsymoff];
+static struct elf_link_hash_entry *
+get_ext_sym_hash_from_cookie (struct elf_reloc_cookie *cookie, unsigned long r_symndx)
+{
+ if (cookie == NULL || cookie->sym_hashes == NULL)
+ return NULL;
- while (h->root.type == bfd_link_hash_indirect
- || h->root.type == bfd_link_hash_warning)
- h = (struct elf_link_hash_entry *) h->root.u.i.link;
+ if (r_symndx >= cookie->locsymcount
+ || ELF_ST_BIND (cookie->locsyms[r_symndx].st_info) != STB_LOCAL)
+ return get_link_hash_entry (cookie->sym_hashes, r_symndx, cookie->extsymoff);
+ return NULL;
+}
+asection *
+_bfd_elf_section_for_symbol (struct elf_reloc_cookie *cookie,
+ unsigned long r_symndx,
+ bool discard)
+{
+ struct elf_link_hash_entry *h;
+ h = get_ext_sym_hash_from_cookie (cookie, r_symndx);
+ if (h != NULL)
+ {
if ((h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak)
&& discarded_section (h->root.u.def.section))
@@ -72,21 +110,18 @@ _bfd_elf_section_for_symbol (struct elf_reloc_cookie *cookie,
else
return NULL;
}
- else
- {
- /* It's not a relocation against a global symbol,
- but it could be a relocation against a local
- symbol for a discarded section. */
- asection *isec;
- Elf_Internal_Sym *isym;
+ /* It's not a relocation against a global symbol,
+ but it could be a relocation against a local
+ symbol for a discarded section. */
+ asection *isec;
+ Elf_Internal_Sym *isym;
- /* Need to: get the symbol; get the section. */
- isym = &cookie->locsyms[r_symndx];
- isec = bfd_section_from_elf_index (cookie->abfd, isym->st_shndx);
- if (isec != NULL
- && discard ? discarded_section (isec) : 1)
- return isec;
- }
+ /* Need to: get the symbol; get the section. */
+ isym = &cookie->locsyms[r_symndx];
+ isec = bfd_section_from_elf_index (cookie->abfd, isym->st_shndx);
+ if (isec != NULL
+ && discard ? discarded_section (isec) : 1)
+ return isec;
return NULL;
}
@@ -8880,7 +8915,6 @@ set_symbol_value (bfd *bfd_with_globals,
size_t symidx,
bfd_vma val)
{
- struct elf_link_hash_entry **sym_hashes;
struct elf_link_hash_entry *h;
size_t extsymoff = locsymcount;
@@ -8904,11 +8938,12 @@ set_symbol_value (bfd *bfd_with_globals,
/* It is a global symbol: set its link type
to "defined" and give it a value. */
- sym_hashes = elf_sym_hashes (bfd_with_globals);
- h = sym_hashes [symidx - extsymoff];
- while (h->root.type == bfd_link_hash_indirect
- || h->root.type == bfd_link_hash_warning)
- h = (struct elf_link_hash_entry *) h->root.u.i.link;
+ h = get_link_hash_entry (elf_sym_hashes (bfd_with_globals), symidx, extsymoff);
+ if (h == NULL)
+ {
+ /* FIXMEL What should we do ? */
+ return;
+ }
h->root.type = bfd_link_hash_defined;
h->root.u.def.value = val;
h->root.u.def.section = bfd_abs_section_ptr;
@@ -11379,10 +11414,19 @@ elf_link_input_bfd (struct elf_final_link_info *flinfo, bfd *input_bfd)
|| (elf_bad_symtab (input_bfd)
&& flinfo->sections[symndx] == NULL))
{
- struct elf_link_hash_entry *h = sym_hashes[symndx - extsymoff];
- while (h->root.type == bfd_link_hash_indirect
- || h->root.type == bfd_link_hash_warning)
- h = (struct elf_link_hash_entry *) h->root.u.i.link;
+ struct elf_link_hash_entry *h;
+
+ h = get_link_hash_entry (sym_hashes, symndx, extsymoff);
+ if (h == NULL)
+ {
+ _bfd_error_handler
+ /* xgettext:c-format */
+ (_("error: %pB: unable to create group section symbol"),
+ input_bfd);
+ bfd_set_error (bfd_error_bad_value);
+ return false;
+ }
+
/* Arrange for symbol to be output. */
h->indx = -2;
elf_section_data (osec)->this_hdr.sh_info = -2;
@@ -11516,7 +11560,7 @@ elf_link_input_bfd (struct elf_final_link_info *flinfo, bfd *input_bfd)
|| (elf_bad_symtab (input_bfd)
&& flinfo->sections[r_symndx] == NULL))
{
- h = sym_hashes[r_symndx - extsymoff];
+ h = get_link_hash_entry (sym_hashes, r_symndx, extsymoff);
/* Badly formatted input files can contain relocs that
reference non-existant symbols. Check here so that
@@ -11525,17 +11569,13 @@ elf_link_input_bfd (struct elf_final_link_info *flinfo, bfd *input_bfd)
{
_bfd_error_handler
/* xgettext:c-format */
- (_("error: %pB contains a reloc (%#" PRIx64 ") for section %pA "
+ (_("error: %pB contains a reloc (%#" PRIx64 ") for section '%pA' "
"that references a non-existent global symbol"),
input_bfd, (uint64_t) rel->r_info, o);
bfd_set_error (bfd_error_bad_value);
return false;
}
- while (h->root.type == bfd_link_hash_indirect
- || h->root.type == bfd_link_hash_warning)
- h = (struct elf_link_hash_entry *) h->root.u.i.link;
-
s_type = h->type;
/* If a plugin symbol is referenced from a non-IR file,
@@ -11751,7 +11791,6 @@ elf_link_input_bfd (struct elf_final_link_info *flinfo, bfd *input_bfd)
&& flinfo->sections[r_symndx] == NULL))
{
struct elf_link_hash_entry *rh;
- unsigned long indx;
/* This is a reloc against a global symbol. We
have not yet output all the local symbols, so
@@ -11760,15 +11799,16 @@ elf_link_input_bfd (struct elf_final_link_info *flinfo, bfd *input_bfd)
reloc to point to the global hash table entry
for this symbol. The symbol index is then
set at the end of bfd_elf_final_link. */
- indx = r_symndx - extsymoff;
- rh = elf_sym_hashes (input_bfd)[indx];
- while (rh->root.type == bfd_link_hash_indirect
- || rh->root.type == bfd_link_hash_warning)
- rh = (struct elf_link_hash_entry *) rh->root.u.i.link;
-
- /* Setting the index to -2 tells
- elf_link_output_extsym that this symbol is
- used by a reloc. */
+ rh = get_link_hash_entry (elf_sym_hashes (input_bfd),
+ r_symndx, extsymoff);
+ if (rh == NULL)
+ {
+ /* FIXME: Generate an error ? */
+ continue;
+ }
+
+ /* Setting the index to -2 tells elf_link_output_extsym
+ that this symbol is used by a reloc. */
BFD_ASSERT (rh->indx < 0);
rh->indx = -2;
*rel_hash = rh;
@@ -13732,25 +13772,21 @@ _bfd_elf_gc_mark_hook (asection *sec,
struct elf_link_hash_entry *h,
Elf_Internal_Sym *sym)
{
- if (h != NULL)
+ if (h == NULL)
+ return bfd_section_from_elf_index (sec->owner, sym->st_shndx);
+
+ switch (h->root.type)
{
- switch (h->root.type)
- {
- case bfd_link_hash_defined:
- case bfd_link_hash_defweak:
- return h->root.u.def.section;
+ case bfd_link_hash_defined:
+ case bfd_link_hash_defweak:
+ return h->root.u.def.section;
- case bfd_link_hash_common:
- return h->root.u.c.p->section;
+ case bfd_link_hash_common:
+ return h->root.u.c.p->section;
- default:
- break;
- }
+ default:
+ return NULL;
}
- else
- return bfd_section_from_elf_index (sec->owner, sym->st_shndx);
-
- return NULL;
}
/* Return the debug definition section. */
@@ -13799,56 +13835,45 @@ _bfd_elf_gc_mark_rsec (struct bfd_link_info *info, asection *sec,
if (r_symndx == STN_UNDEF)
return NULL;
- if (r_symndx >= cookie->locsymcount
- || ELF_ST_BIND (cookie->locsyms[r_symndx].st_info) != STB_LOCAL)
+ h = get_ext_sym_hash_from_cookie (cookie, r_symndx);
+ if (h == NULL)
{
- bool was_marked;
+ /* A corrup tinput file can lead to a situation where the index
+ does not reference either a local or an external symbol. */
+ if (r_symndx >= cookie->locsymcount)
+ return NULL;
- h = cookie->sym_hashes[r_symndx - cookie->extsymoff];
- if (h == NULL)
- {
- info->callbacks->einfo (_("%F%P: corrupt input: %pB\n"),
- sec->owner);
- return NULL;
- }
- while (h->root.type == bfd_link_hash_indirect
- || h->root.type == bfd_link_hash_warning)
- h = (struct elf_link_hash_entry *) h->root.u.i.link;
-
- was_marked = h->mark;
- h->mark = 1;
- /* Keep all aliases of the symbol too. If an object symbol
- needs to be copied into .dynbss then all of its aliases
- should be present as dynamic symbols, not just the one used
- on the copy relocation. */
- hw = h;
- while (hw->is_weakalias)
- {
- hw = hw->u.alias;
- hw->mark = 1;
- }
-
- if (!was_marked && h->start_stop && !h->root.ldscript_def)
- {
- if (info->start_stop_gc)
- return NULL;
-
- /* To work around a glibc bug, mark XXX input sections
- when there is a reference to __start_XXX or __stop_XXX
- symbols. */
- else if (start_stop != NULL)
- {
- asection *s = h->u2.start_stop_section;
- *start_stop = true;
- return s;
- }
- }
-
- return (*gc_mark_hook) (sec, info, cookie->rel, h, NULL);
+ return (*gc_mark_hook) (sec, info, cookie->rel, NULL,
+ &cookie->locsyms[r_symndx]);
}
+ bool was_marked = h->mark;
+ h->mark = 1;
+ /* Keep all aliases of the symbol too. If an object symbol
+ needs to be copied into .dynbss then all of its aliases
+ should be present as dynamic symbols, not just the one used
+ on the copy relocation. */
+ hw = h;
+ while (hw->is_weakalias)
+ {
+ hw = hw->u.alias;
+ hw->mark = 1;
+ }
+ if (!was_marked && h->start_stop && !h->root.ldscript_def)
+ {
+ if (info->start_stop_gc)
+ return NULL;
- return (*gc_mark_hook) (sec, info, cookie->rel, NULL,
- &cookie->locsyms[r_symndx]);
+ /* To work around a glibc bug, mark XXX input sections
+ when there is a reference to __start_XXX or __stop_XXX
+ symbols. */
+ else if (start_stop != NULL)
+ {
+ asection *s = h->u2.start_stop_section;
+ *start_stop = true;
+ return s;
+ }
+ }
+ return (*gc_mark_hook) (sec, info, cookie->rel, h, NULL);
}
/* COOKIE->rel describes a relocation against section SEC, which is
@@ -14860,17 +14885,11 @@ bfd_elf_reloc_symbol_deleted_p (bfd_vma offset, void *cookie)
if (r_symndx == STN_UNDEF)
return true;
- if (r_symndx >= rcookie->locsymcount
- || ELF_ST_BIND (rcookie->locsyms[r_symndx].st_info) != STB_LOCAL)
- {
- struct elf_link_hash_entry *h;
-
- h = rcookie->sym_hashes[r_symndx - rcookie->extsymoff];
-
- while (h->root.type == bfd_link_hash_indirect
- || h->root.type == bfd_link_hash_warning)
- h = (struct elf_link_hash_entry *) h->root.u.i.link;
+ struct elf_link_hash_entry *h;
+ h = get_ext_sym_hash_from_cookie (rcookie, r_symndx);
+ if (h != NULL)
+ {
if ((h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak)
&& (h->root.u.def.section->owner != rcookie->abfd
@@ -14880,6 +14899,10 @@ bfd_elf_reloc_symbol_deleted_p (bfd_vma offset, void *cookie)
}
else
{
+ if (r_symndx >= rcookie->locsymcount)
+ /* This can happen with corrupt input. */
+ return false;
+
/* It's not a relocation against a global symbol,
but it could be a relocation against a local
symbol for a discarded section. */
@@ -14894,6 +14917,7 @@ bfd_elf_reloc_symbol_deleted_p (bfd_vma offset, void *cookie)
|| discarded_section (isec)))
return true;
}
+
return false;
}
return false;
diff --git a/bfd/elfxx-x86.c b/bfd/elfxx-x86.c
index 508fd771da3..8c261cf840a 100644
--- a/bfd/elfxx-x86.c
+++ b/bfd/elfxx-x86.c
@@ -972,15 +972,7 @@ _bfd_x86_elf_check_relocs (bfd *abfd,
goto error_return;
}
- if (r_symndx < symtab_hdr->sh_info)
- h = NULL;
- else
- {
- h = sym_hashes[r_symndx - symtab_hdr->sh_info];
- while (h->root.type == bfd_link_hash_indirect
- || h->root.type == bfd_link_hash_warning)
- h = (struct elf_link_hash_entry *) h->root.u.i.link;
- }
+ h = _bfd_elf_get_link_hash_entry (sym_hashes, r_symndx, symtab_hdr);
if (X86_NEED_DYNAMIC_RELOC_TYPE_P (is_x86_64, r_type)
&& NEED_DYNAMIC_RELOCATION_P (is_x86_64, info, true, h, sec,
@@ -1205,10 +1197,12 @@ _bfd_x86_elf_link_relax_section (bfd *abfd ATTRIBUTE_UNUSED,
else
{
/* Get H and SEC for GENERATE_DYNAMIC_RELOCATION_P below. */
- h = sym_hashes[r_symndx - symtab_hdr->sh_info];
- while (h->root.type == bfd_link_hash_indirect
- || h->root.type == bfd_link_hash_warning)
- h = (struct elf_link_hash_entry *) h->root.u.i.link;
+ h = _bfd_elf_get_link_hash_entry (sym_hashes, r_symndx, symtab_hdr);
+ if (h == NULL)
+ {
+ /* FIXMEL: Issue an error message ? */
+ continue;
+ }
if (h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak)
--
2.43.0
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