[binutils-gdb/binutils-2_43-branch] PR32109, aborting at bfd/bfd.c:1236 in int _bfd_doprnt

[Alan Modra]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=cd3e2b58f2c42197737e5f24943a74c394d04b05

commit cd3e2b58f2c42197737e5f24943a74c394d04b05
Author: Alan Modra <amodra@gmail.com>
Date:   Sun Aug 25 15:20:21 2024 +0930

    PR32109, aborting at bfd/bfd.c:1236 in int _bfd_doprnt
    
    Since bfd_section for .strtab isn't set, print the section index
    instead.  Also, don't return NULL on this error as that results in
    multiple mmap/read of the string table.  (We could return NULL if we
    arranged to set sh_size zero first, but just what we do with fuzzed
    object files is of no concern, and terminating the table might make a
    faulty object file usable.)
    
            PR 32109
            * elf.c (bfd_elf_get_str_section): Remove outdated comment, and
            tweak shstrtabsize test to suit.  Don't use string tab bfd_section
            in error message, use index instead.  Don't return NULL on
            unterminated string section, terminate it.
            (_bfd_elf_get_dynamic_symbols): Similarly terminate string table
            section.
    
    (cherry picked from commit db856d41004301b3a56438efd957ef5cabb91530)

Diff:
---
 bfd/elf.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/bfd/elf.c b/bfd/elf.c
index f85f79e1e35..389c1560d81 100644
--- a/bfd/elf.c
+++ b/bfd/elf.c
@@ -285,9 +285,7 @@ bfd_elf_get_str_section (bfd *abfd, unsigned int shindex)
       offset = i_shdrp[shindex]->sh_offset;
       shstrtabsize = i_shdrp[shindex]->sh_size;
 
-      /* Allocate and clear an extra byte at the end, to prevent crashes
-	 in case the string table is not terminated.  */
-      if (shstrtabsize + 1 <= 1
+      if (shstrtabsize == 0
 	  || bfd_seek (abfd, offset, SEEK_SET) != 0
 	  || (shstrtab
 	      = _bfd_mmap_readonly_persistent (abfd, shstrtabsize)) == NULL)
@@ -297,14 +295,13 @@ bfd_elf_get_str_section (bfd *abfd, unsigned int shindex)
 	     the string table over and over.  */
 	  i_shdrp[shindex]->sh_size = 0;
 	}
-      else if (shstrtab[shstrtabsize - 1] != '\0')
+      else if (shstrtab[shstrtabsize - 1] != 0)
 	{
 	  /* It is an error if a string table isn't terminated.  */
 	  _bfd_error_handler
 	    /* xgettext:c-format */
-	    (_("%pB(%pA): string table is corrupt"),
-	     abfd, i_shdrp[shindex]->bfd_section);
-	  return NULL;
+	    (_("%pB: string table [%u] is corrupt"), abfd, shindex);
+	  shstrtab[shstrtabsize - 1] = 0;
 	}
       i_shdrp[shindex]->contents = shstrtab;
     }
@@ -1914,7 +1911,7 @@ _bfd_elf_get_dynamic_symbols (bfd *abfd, Elf_Internal_Phdr *phdr,
       _bfd_error_handler
 	/* xgettext:c-format */
 	(_("%pB: DT_STRTAB table is corrupt"), abfd);
-      goto error_return;
+      strbuf[dt_strsz - 1] = 0;
     }
 
   /* Get the real symbol count from DT_HASH or DT_GNU_HASH.  Prefer