Skip to content

Add buffer overflow detection #5884

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 4 commits into from
Oct 15, 2025
Merged

Add buffer overflow detection #5884

Changes from 2 commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
d5f05f3
Harden H5C__decode_cache_image_header() by adding buffer overflow checks
bmribler Sep 27, 2025
df86e9d
Committing clang-format changes
github-actions[bot] Sep 27, 2025
9e9f28d
Fix typos
bmribler Sep 28, 2025
17b13b0
Code improvement
bmribler Oct 10, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
19 changes: 14 additions & 5 deletions src/H5Cimage.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1277,7 +1277,8 @@ H5C__decode_cache_image_header(const H5F_t *f, H5C_t *cache_ptr, const uint8_t *
size_t actual_header_len;
size_t expected_header_len;
const uint8_t *p;
herr_t ret_value = SUCCEED; /* Return value */
const uint8_t *p_end = p + buf_size - 1; /* End of the p buffer */
herr_t ret_value = SUCCEED; /* Return value */

FUNC_ENTER_PACKAGE

Expand All @@ -1299,25 +1300,33 @@ H5C__decode_cache_image_header(const H5F_t *f, H5C_t *cache_ptr, const uint8_t *
p += H5C__MDCI_BLOCK_SIGNATURE_LEN;

/* Check version */
if (H5_IS_BUFFER_OVERFLOW(p, 1, p_end))
Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

The buffer overflow check above if (H5_IS_BUFFER_OVERFLOW(p, H5C__MDCI_BLOCK_SIGNATURE_LEN, *buf + buf_size - 1)) should probably be updated to make use of p_end instead for consistency.

Copy link
Collaborator Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

@jhendersonHDF I made the change. Thanks!

HGOTO_ERROR(H5E_CACHE, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");
version = *p++;
if (version != (uint8_t)H5C__MDCI_BLOCK_VERSION_0)
HGOTO_ERROR(H5E_CACHE, H5E_BADVALUE, FAIL, "Bad metadata cache image version");

/* Decode flags */
if (H5_IS_BUFFER_OVERFLOW(p, 1, p_end))
HGOTO_ERROR(H5E_CACHE, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");
flags = *p++;
if (flags & H5C__MDCI_HEADER_HAVE_RESIZE_STATUS)
have_resize_status = true;
if (have_resize_status)
HGOTO_ERROR(H5E_CACHE, H5E_BADVALUE, FAIL, "MDC resize status not yet supported");

/* Read image data length */
if (H5_IS_BUFFER_OVERFLOW(p, H5F_sizeof_size(f), p_end))
HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");
H5F_DECODE_LENGTH(f, p, cache_ptr->image_data_len);

/* For now -- will become <= eventually */
if (cache_ptr->image_data_len != cache_ptr->image_len)
HGOTO_ERROR(H5E_CACHE, H5E_BADVALUE, FAIL, "Bad metadata cache image data length");

/* Read num entries */
if (H5_IS_BUFFER_OVERFLOW(p, 4, p_end))
HGOTO_ERROR(H5E_OHDR, H5E_OVERFLOW, NULL, "ran off end of input buffer while decoding");
UINT32DECODE(p, cache_ptr->num_entries_in_image);
if (cache_ptr->num_entries_in_image == 0)
HGOTO_ERROR(H5E_CACHE, H5E_BADVALUE, FAIL, "Bad metadata cache entry count");
Expand Down Expand Up @@ -2392,18 +2401,18 @@ H5C__reconstruct_cache_contents(H5F_t *f, H5C_t *cache_ptr)
assert(cache_ptr->image_len > 0);

/* Decode metadata cache image header */
p = (uint8_t *)cache_ptr->image_buffer;
image_len = cache_ptr->image_len;
if (H5C__decode_cache_image_header(f, cache_ptr, &p, image_len + 1) < 0)
p = (uint8_t *)cache_ptr->image_buffer;
if (H5C__decode_cache_image_header(f, cache_ptr, &p, cache_ptr->image_len + 1) < 0)
HGOTO_ERROR(H5E_CACHE, H5E_CANTDECODE, FAIL, "cache image header decode failed");
assert((size_t)(p - (uint8_t *)cache_ptr->image_buffer) < image_len);
assert((size_t)(p - (uint8_t *)cache_ptr->image_buffer) < cache_ptr->image_len);

/* The image_data_len and # of entries should be defined now */
assert(cache_ptr->image_data_len > 0);
assert(cache_ptr->image_data_len <= cache_ptr->image_len);
assert(cache_ptr->num_entries_in_image > 0);

/* Reconstruct entries in image */
image_len = cache_ptr->image_len;
for (u = 0; u < cache_ptr->num_entries_in_image; u++) {
/* Create the prefetched entry described by the ith
* entry in cache_ptr->image_entrise.
Expand Down
Loading