Fix illegal memory accesses in the assembler when attempting to parse corrup tinput files.

PR 23054
	* cond.c (s_ifsef): Replace use of obstack_copy with obstack_alloc
	followed by memcpy.
	(s_if, s_ifb, s_ifc, s_ifeqs): Likewise.
	* obj-elf.c (elf_adjust_symtab): Check for local symbols before
	attempting to dereference the sy_next field of a symbol.
	* stabs.c (get_stab_string_offset): Fail if there is no string
	following the stab directive.
This commit is contained in:
Nick Clifton
2018-04-16 16:39:15 +01:00
parent fc7aa874aa
commit c77852c891
4 changed files with 41 additions and 17 deletions

View File

@@ -28,7 +28,8 @@
scanned. */
struct obstack cond_obstack;
struct file_line {
struct file_line
{
const char *file;
unsigned int line;
};
@@ -36,7 +37,8 @@ struct file_line {
/* We push one of these structures for each .if, and pop it at the
.endif. */
struct conditional_frame {
struct conditional_frame
{
/* The source file & line number of the "if". */
struct file_line if_file_line;
/* The source file & line of the "else". */
@@ -108,9 +110,9 @@ s_ifdef (int test_defined)
cframe.ignoring = ! (test_defined ^ is_defined);
}
current_cframe = ((struct conditional_frame *)
obstack_copy (&cond_obstack, &cframe,
sizeof (cframe)));
current_cframe =
(struct conditional_frame *) obstack_alloc (&cond_obstack, sizeof cframe);
memcpy (current_cframe, &cframe, sizeof cframe);
if (LISTING_SKIP_COND ()
&& cframe.ignoring
@@ -166,8 +168,9 @@ s_if (int arg)
using an undefined result. No big deal. */
initialize_cframe (&cframe);
cframe.ignoring = cframe.dead_tree || ! t;
current_cframe = ((struct conditional_frame *)
obstack_copy (&cond_obstack, &cframe, sizeof (cframe)));
current_cframe =
(struct conditional_frame *) obstack_alloc (&cond_obstack, sizeof cframe);
memcpy (current_cframe, & cframe, sizeof cframe);
if (LISTING_SKIP_COND ()
&& cframe.ignoring
@@ -202,9 +205,9 @@ s_ifb (int test_blank)
cframe.ignoring = (test_blank == !is_eol);
}
current_cframe = ((struct conditional_frame *)
obstack_copy (&cond_obstack, &cframe,
sizeof (cframe)));
current_cframe =
(struct conditional_frame *) obstack_alloc (&cond_obstack, sizeof cframe);
memcpy (current_cframe, &cframe, sizeof cframe);
if (LISTING_SKIP_COND ()
&& cframe.ignoring
@@ -283,10 +286,11 @@ s_ifc (int arg)
initialize_cframe (&cframe);
cframe.ignoring = cframe.dead_tree || ! (res ^ arg);
current_cframe = ((struct conditional_frame *)
obstack_copy (&cond_obstack, &cframe, sizeof (cframe)));
if (LISTING_SKIP_COND ()
current_cframe =
(struct conditional_frame *) obstack_alloc (&cond_obstack, sizeof cframe);
memcpy (current_cframe, &cframe, sizeof cframe);
if (LISTING_SKIP_COND ()
&& cframe.ignoring
&& (cframe.previous_cframe == NULL
|| ! cframe.previous_cframe->ignoring))
@@ -477,8 +481,9 @@ s_ifeqs (int arg)
initialize_cframe (&cframe);
cframe.ignoring = cframe.dead_tree || ! (res ^ arg);
current_cframe = ((struct conditional_frame *)
obstack_copy (&cond_obstack, &cframe, sizeof (cframe)));
current_cframe =
(struct conditional_frame *) obstack_alloc (&cond_obstack, sizeof cframe);
memcpy (current_cframe, &cframe, sizeof cframe);
if (LISTING_SKIP_COND ()
&& cframe.ignoring
@@ -548,6 +553,7 @@ cond_finish_check (int nest)
as_bad (_("end of macro inside conditional"));
else
as_bad (_("end of file inside conditional"));
as_bad_where (current_cframe->if_file_line.file,
current_cframe->if_file_line.line,
_("here is the start of the unterminated conditional"));