[PATCH] Fix the error in determining the range of file name length
Alan Modra
amodra@gmail.com
Wed Sep 25 12:20:55 GMT 2024
On Fri, Sep 13, 2024 at 03:41:41AM +0000, Song, Jiaying (CN) wrote:
> Hi Martin, Alan, and team,
>
> Thank you for your attention to this issue. Based on recent tests,
> it appears that the check (strlen(input) + 2) > NAME_MAX in the code
> is incorrect because it does not leave sufficient buffer space. This
> is because, in addition to the tmp_prefix generated by appending an
> "_" symbol to input, the temporary files also have a suffix
> s00000.o. Consequently, the final filename adds 9 extra bytes to the
> input.
Yes. Would you mind testing the following?
>From 8b75913f44537b51a14f771f616deea747d00c76 Mon Sep 17 00:00:00 2001
From: Alan Modra <amodra@gmail.com>
Date: Wed, 25 Sep 2024 10:42:36 +0930
Subject: Re: dlltool: file name too long
Allow for "snnnnn.o" suffix when testing against NAME_MAX, and tidy
TMP_STUB handling by overwrite prior nnnnn.o string rather than
copying the name.
* dlltool.c (TMP_STUB): Add "nnnnn.o" to format.
(make_one_lib_file): Localise variables. Don't copy TMP_STUB,
overwrite suffix instead.
(gen_lib_file): Similarly.
(main): Allow for max suffix when testing against NAME_MAX.
diff --git a/binutils/dlltool.c b/binutils/dlltool.c
index 6dc16a9ed84..01d6cf7d392 100644
--- a/binutils/dlltool.c
+++ b/binutils/dlltool.c
@@ -505,7 +505,7 @@ static char *tmp_stub_buf;
#define TMP_HEAD_O dlltmp (&tmp_head_o_buf, "%sh.o")
#define TMP_TAIL_S dlltmp (&tmp_tail_s_buf, "%st.s")
#define TMP_TAIL_O dlltmp (&tmp_tail_o_buf, "%st.o")
-#define TMP_STUB dlltmp (&tmp_stub_buf, "%ss")
+#define TMP_STUB dlltmp (&tmp_stub_buf, "%ssnnnnn.o")
/* This bit of assembly does jmp * .... */
static const unsigned char i386_jtab[] =
@@ -2365,26 +2365,11 @@ make_imp_label (const char *prefix, const char *name)
static bfd *
make_one_lib_file (export_type *exp, int i, int delay)
{
- bfd * abfd;
- asymbol * exp_label;
- asymbol * iname = 0;
- asymbol * iname2;
- asymbol * iname_lab;
- asymbol ** iname_lab_pp;
- asymbol ** iname_pp;
-#ifndef EXTRA
-#define EXTRA 0
-#endif
- asymbol * ptrs[NSECS + 4 + EXTRA + 1];
- flagword applicable;
- char * outname = xmalloc (strlen (TMP_STUB) + 10);
- int oidx = 0;
-
-
- sprintf (outname, "%s%05d.o", TMP_STUB, i);
-
- abfd = bfd_openw (outname, HOW_BFD_WRITE_TARGET);
+ char *outname = TMP_STUB;
+ size_t name_len = strlen (outname);
+ sprintf (outname + name_len - 7, "%05d.o", i);
+ bfd *abfd = bfd_openw (outname, HOW_BFD_WRITE_TARGET);
if (!abfd)
/* xgettext:c-format */
fatal (_("bfd_open failed open stub file: %s: %s"),
@@ -2401,9 +2386,13 @@ make_one_lib_file (export_type *exp, int i, int delay)
bfd_set_private_flags (abfd, F_INTERWORK);
#endif
- applicable = bfd_applicable_section_flags (abfd);
-
/* First make symbols for the sections. */
+ flagword applicable = bfd_applicable_section_flags (abfd);
+#ifndef EXTRA
+#define EXTRA 0
+#endif
+ asymbol *ptrs[NSECS + 4 + EXTRA + 1];
+ int oidx = 0;
for (i = 0; i < NSECS; i++)
{
sinfo *si = secdata + i;
@@ -2430,7 +2419,7 @@ make_one_lib_file (export_type *exp, int i, int delay)
if (! exp->data)
{
- exp_label = bfd_make_empty_symbol (abfd);
+ asymbol *exp_label = bfd_make_empty_symbol (abfd);
exp_label->name = make_imp_label ("", exp->name);
exp_label->section = secdata[TEXT].sec;
exp_label->flags = BSF_GLOBAL;
@@ -2446,6 +2435,7 @@ make_one_lib_file (export_type *exp, int i, int delay)
/* Generate imp symbols with one underscore for Microsoft
compatibility, and with two underscores for backward
compatibility with old versions of cygwin. */
+ asymbol *iname = NULL;
if (create_compat_implib)
{
iname = bfd_make_empty_symbol (abfd);
@@ -2455,25 +2445,24 @@ make_one_lib_file (export_type *exp, int i, int delay)
iname->value = 0;
}
- iname2 = bfd_make_empty_symbol (abfd);
+ asymbol *iname2 = bfd_make_empty_symbol (abfd);
iname2->name = make_imp_label ("__imp_", exp->name);
iname2->section = secdata[IDATA5].sec;
iname2->flags = BSF_GLOBAL;
iname2->value = 0;
- iname_lab = bfd_make_empty_symbol (abfd);
-
+ asymbol *iname_lab = bfd_make_empty_symbol (abfd);
iname_lab->name = head_label;
iname_lab->section = bfd_und_section_ptr;
iname_lab->flags = 0;
iname_lab->value = 0;
- iname_pp = ptrs + oidx;
+ asymbol **iname_pp = ptrs + oidx;
if (create_compat_implib)
ptrs[oidx++] = iname;
ptrs[oidx++] = iname2;
- iname_lab_pp = ptrs + oidx;
+ asymbol **iname_lab_pp = ptrs + oidx;
ptrs[oidx++] = iname_lab;
ptrs[oidx] = 0;
@@ -3056,29 +3045,26 @@ gen_lib_file (int delay)
if (dontdeltemps < 2)
{
- char *name;
- size_t stub_len = strlen (TMP_STUB);
+ char *name = TMP_STUB;
+ size_t name_len = strlen (name);
- name = xmalloc (stub_len + 10);
- memcpy (name, TMP_STUB, stub_len);
for (i = 0; (exp = d_exports_lexically[i]); i++)
{
/* Don't delete non-existent stubs for PRIVATE entries. */
if (exp->private)
continue;
- sprintf (name + stub_len, "%05d.o", i);
+ sprintf (name + name_len - 7, "%05d.o", i);
if (unlink (name) < 0)
/* xgettext:c-format */
non_fatal (_("cannot delete %s: %s"), name, strerror (errno));
if (ext_prefix_alias)
{
- sprintf (name + stub_len, "%05d.o", i + PREFIX_ALIAS_BASE);
+ sprintf (name + name_len - 7, "%05d.o", i + PREFIX_ALIAS_BASE);
if (unlink (name) < 0)
/* xgettext:c-format */
non_fatal (_("cannot delete %s: %s"), name, strerror (errno));
}
}
- free (name);
}
inform (_("Created lib file"));
@@ -4069,7 +4055,7 @@ main (int ac, char **av)
{
/* If possible use a deterministic prefix. */
const char *input = imp_name ? imp_name : delayimp_name;
- if (input && strlen (input) + 2 <= NAME_MAX)
+ if (input && strlen (input) + sizeof ("_snnnnn.o") - 1 <= NAME_MAX)
{
tmp_prefix = xmalloc (strlen (input) + 2);
sprintf (tmp_prefix, "%s_", input);
--
Alan Modra
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