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Add fbounds-safety annotations for data.

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Reasoning:

Analysis of `GetLE32` and its called function `GetLE16`
(src/utils/utils.h:95) showed that `GetLE32` requires access to 4
bytes starting from `data`. `GetLE16` accesses 2 bytes.

Therefore, `WEBP_COUNTED_BY(4)` was added to the `data` parameter of
`GetLE32`. Similarly, `WEBP_COUNTED_BY(2)` was added to `GetLE16`.

During this analysis, related functions `GetLE24`, `PutLE16`,
`PutLE24`, and `PutLE32` (src/utils/utils.h lines 99-123) were also
identified as needing similar annotations. They were annotated with
`WEBP_COUNTED_BY(3)`, `WEBP_COUNTED_BY(2)`, `WEBP_COUNTED_BY(3)`, and
`WEBP_COUNTED_BY(4)` respectively, based on the number of bytes they
access or modify.

Bug: 432511821
Change-Id: I5783392bc8dcaa2f346a81928ef496fc52da3a30
This commit is contained in:
Arman Hasanzadeh
2025-08-18 23:41:03 -07:00
parent 7903644f24
commit 46d65e4a19
1 changed files with 10 additions and 6 deletions
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16
src/utils/utils.h
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@@ -93,32 +93,36 @@ static WEBP_INLINE void WebPInt32ToMem(uint8_t* const ptr, int val) {
// Reading/writing data.
// Read 16, 24 or 32 bits stored in little-endian order.
static WEBP_INLINE int GetLE16(const uint8_t* const data) {
static WEBP_INLINE int GetLE16(const uint8_t* const WEBP_COUNTED_BY(2) data) {
return (int)(data[0] << 0) | (data[1] << 8);
}
static WEBP_INLINE int GetLE24(const uint8_t* const data) {
static WEBP_INLINE int GetLE24(const uint8_t* const WEBP_COUNTED_BY(3) data) {
return GetLE16(data) | (data[2] << 16);
}
static WEBP_INLINE uint32_t GetLE32(const uint8_t* const data) {
static WEBP_INLINE uint32_t GetLE32(const uint8_t* const WEBP_COUNTED_BY(4)
data) {
return GetLE16(data) | ((uint32_t)GetLE16(data + 2) << 16);
}
// Store 16, 24 or 32 bits in little-endian order.
static WEBP_INLINE void PutLE16(uint8_t* const data, int val) {
static WEBP_INLINE void PutLE16(uint8_t* const WEBP_COUNTED_BY(2) data,
int val) {
assert(val < (1 << 16));
data[0] = (val >> 0) & 0xff;
data[1] = (val >> 8) & 0xff;
}
static WEBP_INLINE void PutLE24(uint8_t* const data, int val) {
static WEBP_INLINE void PutLE24(uint8_t* const WEBP_COUNTED_BY(3) data,
int val) {
assert(val < (1 << 24));
PutLE16(data, val & 0xffff);
data[2] = (val >> 16) & 0xff;
}
static WEBP_INLINE void PutLE32(uint8_t* const data, uint32_t val) {
static WEBP_INLINE void PutLE32(uint8_t* const WEBP_COUNTED_BY(4) data,
uint32_t val) {
PutLE16(data, (int)(val & 0xffff));
PutLE16(data + 2, (int)(val >> 16));
}