i386msdos uninitialised read

Also reinstate ld i386aout for i386-msdos target, which doesn't build
otherwise.

bfd/
	* i386msdos.c (msdos_object_p): Don't access e_lfanew when that
	field hasn't been read.  Remove unnecessary casts.
ld/
	* Makefile.am (ALL_EMULATION_SOURCES): Reinstate ei386aout.c.
	Include ei386aout dep file.
	* Makefile.in: Regenerate.
	* po/BLD-POTFILES.in: Regenerate.

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 2e0abc83599a69902193b438b957c7e134785f97..c513ebd7537bc2ce66b047fab9367ddc0ebd217f 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,8 @@
+2020-03-23  Alan Modra  <amodra@gmail.com>
+
+       * i386msdos.c (msdos_object_p): Don't access e_lfanew when that
+       field hasn't been read.  Remove unnecessary casts.
+
 2020-03-22  Alan Modra  <amodra@gmail.com>
 
        * coff64-rs6000.c (xcoff64_slurp_armap): Ensure size is large

diff --git a/bfd/i386msdos.c b/bfd/i386msdos.c
index 5b56751cd30bd59f36337ab13548d8085cc894ad..e9307a7a4243df3a95d6715d01bbf35e1e7ab645 100644 (file)
--- a/bfd/i386msdos.c
+++ b/bfd/i386msdos.c
@@ -47,10 +47,10 @@ msdos_object_p (bfd *abfd)
   struct external_DOS_hdr hdr;
   bfd_byte buffer[2];
   asection *section;
-  unsigned int size;
+  bfd_size_type size;
 
   if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0
-      || bfd_bread (&hdr, (bfd_size_type) sizeof (hdr), abfd) < DOS_HDR_SIZE)
+      || (size = bfd_bread (&hdr, sizeof (hdr), abfd)) < DOS_HDR_SIZE)
     {
       if (bfd_get_error () != bfd_error_system_call)
        bfd_set_error (bfd_error_wrong_format);
@@ -67,9 +67,11 @@ msdos_object_p (bfd *abfd)
      e_lfanew field will be valid and point to a header beginning with one of
      the relevant signatures.  If not, e_lfanew might point to anything, so
      don't bail if we can't read there.  */
-  if (H_GET_16 (abfd, hdr.e_cparhdr) < 4
-      || bfd_seek (abfd, (file_ptr) H_GET_32 (abfd, hdr.e_lfanew), SEEK_SET) != 0
-      || bfd_bread (buffer, (bfd_size_type) 2, abfd) != 2)
+  if (size < offsetof (struct external_DOS_hdr, e_lfanew) + 4
+      || H_GET_16 (abfd, hdr.e_cparhdr) < 4)
+    ;
+  else if (bfd_seek (abfd, H_GET_32 (abfd, hdr.e_lfanew), SEEK_SET) != 0
+          || bfd_bread (buffer, (bfd_size_type) 2, abfd) != 2)
     {
       if (bfd_get_error () == bfd_error_system_call)
        return NULL;
@@ -102,7 +104,7 @@ msdos_object_p (bfd *abfd)
   size += H_GET_16 (abfd, hdr.e_cblp);
 
   /* Check that the size is valid.  */
-  if (bfd_seek (abfd, (file_ptr) (section->filepos + size), SEEK_SET) != 0)
+  if (bfd_seek (abfd, section->filepos + size, SEEK_SET) != 0)
     {
       if (bfd_get_error () != bfd_error_system_call)
        bfd_set_error (bfd_error_wrong_format);

diff --git a/ld/ChangeLog b/ld/ChangeLog
index 16c8b8b0698ed2a6c1a0936a4ad960aa91d19043..12efa1117fe3b95d023390d37622af5994496900 100644 (file)
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,10 @@
+2020-03-23  Alan Modra  <amodra@gmail.com>
+
+       * Makefile.am (ALL_EMULATION_SOURCES): Reinstate ei386aout.c.
+       Include ei386aout dep file.
+       * Makefile.in: Regenerate.
+       * po/BLD-POTFILES.in: Regenerate.
+
 2020-03-20  H.J. Lu  <hongjiu.lu@intel.com>
 
        * testsuite/ld-plugin/lto.exp (lto_link_tests): Run PR ld/25355

diff --git a/ld/Makefile.am b/ld/Makefile.am
index 4a9b8404b7b1c1366fb867669d4900a2a3a7ae4d..a64899fc091fe00115c73e9e687a95cefe274836 100644 (file)
--- a/ld/Makefile.am
+++ b/ld/Makefile.am
@@ -312,6 +312,7 @@ ALL_EMULATION_SOURCES = \
        ehppalinux.c \
        ehppanbsd.c \
        ehppaobsd.c \
+       ei386aout.c \
        ei386beos.c \
        ei386bsd.c \
        ei386go32.c \
@@ -800,6 +801,7 @@ $(ALL_EMULATION_SOURCES) $(ALL_64_EMULATION_SOURCES): $(GEN_DEPENDS)
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ehppalinux.Pc@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ehppanbsd.Pc@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ehppaobsd.Pc@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ei386aout.Pc@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ei386beos.Pc@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ei386bsd.Pc@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ei386go32.Pc@am__quote@

diff --git a/ld/Makefile.in b/ld/Makefile.in
index 46d9b14077924f4fc8f1f4ff5078479e41bdd670..b34455b1f86643e025ae3206c69d4134b240f1c7 100644 (file)
--- a/ld/Makefile.in
+++ b/ld/Makefile.in
@@ -802,6 +802,7 @@ ALL_EMULATION_SOURCES = \
        ehppalinux.c \
        ehppanbsd.c \
        ehppaobsd.c \
+       ei386aout.c \
        ei386beos.c \
        ei386bsd.c \
        ei386go32.c \
@@ -1418,6 +1419,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ehppalinux.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ehppanbsd.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ehppaobsd.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ei386aout.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ei386beos.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ei386bsd.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ei386go32.Po@am__quote@
@@ -2404,6 +2406,7 @@ $(ALL_EMULATION_SOURCES) $(ALL_64_EMULATION_SOURCES): $(GEN_DEPENDS)
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ehppalinux.Pc@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ehppanbsd.Pc@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ehppaobsd.Pc@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ei386aout.Pc@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ei386beos.Pc@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ei386bsd.Pc@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/ei386go32.Pc@am__quote@

diff --git a/ld/po/BLD-POTFILES.in b/ld/po/BLD-POTFILES.in
index 3157480c6f708571259c8947dcdb630742d25687..70f5ea9fa4bfcf9ac6b140583c878c61d8627069 100644 (file)
--- a/ld/po/BLD-POTFILES.in
+++ b/ld/po/BLD-POTFILES.in
@@ -222,6 +222,7 @@ ehppaelf.c
 ehppalinux.c
 ehppanbsd.c
 ehppaobsd.c
+ei386aout.c
 ei386beos.c
 ei386bsd.c
 ei386go32.c