asan: heap buffer overflow in mmo_scan
mmo_get_loc needs to handle arbitrary vma and size chunks. Fuzzers found that it wasn't working so well when the end of chunks were getting close to address wrap-around. * mmo.c (mmo_get_loc): Make "size" unsigned. Avoid arithmetic overflow when calculating whether range hits an existing chunk.
This commit is contained in:
parent
11c6a7c623
commit
2bda15d73c
26
bfd/mmo.c
26
bfd/mmo.c
@ -382,7 +382,7 @@ static bool mmo_scan (bfd *);
|
||||
static asection *mmo_decide_section (bfd *, bfd_vma);
|
||||
static asection *mmo_get_generic_spec_data_section (bfd *, int);
|
||||
static asection *mmo_get_spec_section (bfd *, int);
|
||||
static bfd_byte *mmo_get_loc (asection *, bfd_vma, int);
|
||||
static bfd_byte *mmo_get_loc (asection *, bfd_vma, unsigned int);
|
||||
static bfd_cleanup mmo_object_p (bfd *);
|
||||
static void mmo_map_set_sizes (bfd *, asection *, void *);
|
||||
static bool mmo_get_symbols (bfd *);
|
||||
@ -1492,7 +1492,7 @@ SUBSECTION
|
||||
MMO_SEC_CONTENTS_CHUNK_SIZE. */
|
||||
|
||||
static bfd_byte *
|
||||
mmo_get_loc (asection *sec, bfd_vma vma, int size)
|
||||
mmo_get_loc (asection *sec, bfd_vma vma, unsigned int size)
|
||||
{
|
||||
bfd_size_type allocated_size;
|
||||
struct mmo_section_data_struct *sdatap = mmo_section_data (sec);
|
||||
@ -1504,27 +1504,29 @@ mmo_get_loc (asection *sec, bfd_vma vma, int size)
|
||||
for (; datap != NULL; datap = datap->next)
|
||||
{
|
||||
if (datap->where <= vma
|
||||
&& datap->where + datap->size >= vma + size)
|
||||
return datap->data + vma - datap->where;
|
||||
&& datap->size >= size
|
||||
&& datap->size - size >= vma - datap->where)
|
||||
return datap->data + (vma - datap->where);
|
||||
else if (datap->where <= vma
|
||||
&& datap->where + datap->allocated_size >= vma + size
|
||||
&& datap->allocated_size >= size
|
||||
&& datap->allocated_size - size >= vma - datap->where
|
||||
/* Only munch on the "allocated size" if it does not
|
||||
overlap the next chunk. */
|
||||
&& (datap->next == NULL || datap->next->where >= vma + size))
|
||||
{
|
||||
/* There was room allocated, but the size wasn't set to include
|
||||
it. Do that now. */
|
||||
datap->size += (vma + size) - (datap->where + datap->size);
|
||||
datap->size = vma - datap->where + size;
|
||||
|
||||
/* Update the section size. This happens only if we update the
|
||||
32-bit-aligned chunk size. Callers that have
|
||||
non-32-bit-aligned sections should do all allocation and
|
||||
size-setting by themselves or at least set the section size
|
||||
after the last allocating call to this function. */
|
||||
if (vma + size > sec->vma + sec->size)
|
||||
sec->size += (vma + size) - (sec->vma + sec->size);
|
||||
if (vma - sec->vma + size > sec->size)
|
||||
sec->size = vma - sec->vma + size;
|
||||
|
||||
return datap->data + vma - datap->where;
|
||||
return datap->data + (vma - datap->where);
|
||||
}
|
||||
}
|
||||
|
||||
@ -1535,7 +1537,7 @@ mmo_get_loc (asection *sec, bfd_vma vma, int size)
|
||||
for no more than MMO_SEC_CONTENTS_CHUNK_SIZE will always get resolved. */
|
||||
|
||||
for (datap = sdatap->head; datap != NULL; datap = datap->next)
|
||||
if ((datap->where <= vma && datap->where + datap->size > vma)
|
||||
if ((datap->where <= vma && datap->size > vma - datap->where)
|
||||
|| (datap->where < vma + size
|
||||
&& datap->where + datap->size >= vma + size))
|
||||
return NULL;
|
||||
@ -1583,8 +1585,8 @@ mmo_get_loc (asection *sec, bfd_vma vma, int size)
|
||||
|
||||
/* Update the section size. This happens only when we add contents and
|
||||
re-size as we go. The section size will then be aligned to 32 bits. */
|
||||
if (vma + size > sec->vma + sec->size)
|
||||
sec->size += (vma + size) - (sec->vma + sec->size);
|
||||
if (vma - sec->vma + size > sec->size)
|
||||
sec->size = vma - sec->vma + size;
|
||||
return entry->data;
|
||||
}
|
||||
|
||||
|
Loading…
x
Reference in New Issue
Block a user