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| author | Nick Clifton <nickc@redhat.com> | 2018-02-28 11:50:49 +0000 |
|---|---|---|
| committer | Nick Clifton <nickc@redhat.com> | 2018-02-28 11:53:06 +0000 |
| commit | 12c963421d045a127c413a0722062b9932c50aa9 (patch) | |
| tree | c708ba5d2f686c3fec620cc676ce54f704478770 /bfd/dwarf2.c | |
| parent | 116acb2c268c89c89186673a7c92620d21825b25 (diff) | |
| download | gdb-12c963421d045a127c413a0722062b9932c50aa9.zip gdb-12c963421d045a127c413a0722062b9932c50aa9.tar.gz gdb-12c963421d045a127c413a0722062b9932c50aa9.tar.bz2 | |
Catch integer overflows/underflows when parsing corrupt DWARF FORM blocks.
PR 22895
PR 22893
* dwarf2.c (read_n_bytes): Replace size parameter with dwarf_block
pointer. Drop unused abfd parameter. Check the size of the block
before initialising the data field. Return the end pointer if the
size is invalid.
(read_attribute_value): Adjust invocations of read_n_bytes.
Diffstat (limited to 'bfd/dwarf2.c')
| -rw-r--r-- | bfd/dwarf2.c | 36 |
1 files changed, 21 insertions, 15 deletions
diff --git a/bfd/dwarf2.c b/bfd/dwarf2.c index 2413542..ca22db7 100644 --- a/bfd/dwarf2.c +++ b/bfd/dwarf2.c @@ -623,14 +623,24 @@ read_8_bytes (bfd *abfd, bfd_byte *buf, bfd_byte *end) } static bfd_byte * -read_n_bytes (bfd *abfd ATTRIBUTE_UNUSED, - bfd_byte *buf, - bfd_byte *end, - unsigned int size ATTRIBUTE_UNUSED) +read_n_bytes (bfd_byte * buf, + bfd_byte * end, + struct dwarf_block * block) { - if (buf + size > end) - return NULL; - return buf; + unsigned int size = block->size; + bfd_byte * block_end = buf + size; + + if (block_end > end || block_end < buf) + { + block->data = NULL; + block->size = 0; + return end; + } + else + { + block->data = buf; + return block_end; + } } /* Scans a NUL terminated string starting at BUF, returning a pointer to it. @@ -1128,8 +1138,7 @@ read_attribute_value (struct attribute * attr, return NULL; blk->size = read_2_bytes (abfd, info_ptr, info_ptr_end); info_ptr += 2; - blk->data = read_n_bytes (abfd, info_ptr, info_ptr_end, blk->size); - info_ptr += blk->size; + info_ptr = read_n_bytes (info_ptr, info_ptr_end, blk); attr->u.blk = blk; break; case DW_FORM_block4: @@ -1139,8 +1148,7 @@ read_attribute_value (struct attribute * attr, return NULL; blk->size = read_4_bytes (abfd, info_ptr, info_ptr_end); info_ptr += 4; - blk->data = read_n_bytes (abfd, info_ptr, info_ptr_end, blk->size); - info_ptr += blk->size; + info_ptr = read_n_bytes (info_ptr, info_ptr_end, blk); attr->u.blk = blk; break; case DW_FORM_data2: @@ -1180,8 +1188,7 @@ read_attribute_value (struct attribute * attr, blk->size = _bfd_safe_read_leb128 (abfd, info_ptr, &bytes_read, FALSE, info_ptr_end); info_ptr += bytes_read; - blk->data = read_n_bytes (abfd, info_ptr, info_ptr_end, blk->size); - info_ptr += blk->size; + info_ptr = read_n_bytes (info_ptr, info_ptr_end, blk); attr->u.blk = blk; break; case DW_FORM_block1: @@ -1191,8 +1198,7 @@ read_attribute_value (struct attribute * attr, return NULL; blk->size = read_1_byte (abfd, info_ptr, info_ptr_end); info_ptr += 1; - blk->data = read_n_bytes (abfd, info_ptr, info_ptr_end, blk->size); - info_ptr += blk->size; + info_ptr = read_n_bytes (info_ptr, info_ptr_end, blk); attr->u.blk = blk; break; case DW_FORM_data1: |