diff options
Diffstat (limited to 'tiffer.h')
| -rw-r--r-- | tiffer.h | 15 |
1 files changed, 10 insertions, 5 deletions
@@ -15,9 +15,10 @@ // CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. // +#include <stdbool.h> +#include <stddef.h> #include <stdint.h> #include <string.h> -#include <stdbool.h> // --- Utilities --------------------------------------------------------------- @@ -85,7 +86,7 @@ struct tiffer { static bool tiffer_u32(struct tiffer *self, uint32_t *u) { - if (self->p < self->begin || self->p + 4 > self->end) + if (self->end - self->p < 4) return false; *u = self->un->u32(self->p); @@ -96,7 +97,7 @@ tiffer_u32(struct tiffer *self, uint32_t *u) static bool tiffer_u16(struct tiffer *self, uint16_t *u) { - if (self->p < self->begin || self->p + 2 > self->end) + if (self->end - self->p < 2) return false; *u = self->un->u16(self->p); @@ -160,6 +161,9 @@ static bool tiffer_subifd( const struct tiffer *self, uint32_t offset, struct tiffer *subreader) { + if (self->end - self->begin < offset) + return false; + *subreader = *self; subreader->p = subreader->begin + offset; return tiffer_u16(subreader, &subreader->remaining_fields); @@ -323,14 +327,15 @@ tiffer_next_entry(struct tiffer *self, struct tiffer_entry *entry) if (values_size <= sizeof offset) { entry->p = self->p; self->p += sizeof offset; - } else if (tiffer_u32(self, &offset)) { + } else if (tiffer_u32(self, &offset) && self->end - self->begin >= offset) { entry->p = self->begin + offset; } else { return false; } // All entries are pre-checked not to overflow. - if (entry->p + values_size > self->end) + if (values_size > PTRDIFF_MAX || + self->end - entry->p < (ptrdiff_t) values_size) return false; // Setting it at the end may provide an indication while debugging. |