| Summary: | nettle: use size_t for sizes, protect computations | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 7 | Reporter: | Florian Weimer <fweimer> |
| Component: | nettle | Assignee: | Nikos Mavrogiannopoulos <nmavrogi> |
| Status: | CLOSED WONTFIX | QA Contact: | BaseOS QE Security Team <qe-baseos-security> |
| Severity: | low | Docs Contact: | |
| Priority: | low | ||
| Version: | 7.0 | CC: | nmavrogi |
| Target Milestone: | rc | ||
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2013-12-13 16:01:59 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Bug Depends On: | |||
| Bug Blocks: | 1033527 | ||
This is fixed in nettle's master branch, at the cost of an ABI change. I don't think there is much we can do on that (except maintaining a local version of nettle). Nevertheless, I think the impact is minimal as I don't see the nettle's buffer.h to be used in the projects using nettle. |
buffer.h uses unsigned values for keeping track of allocated sizes. This means that a call to nettle_buffer_grow could silently truncate a large argument of type size_t (on 64 bit systems), for example. This issue also applies to nettle_realloc_func Furthermore, a size computation in nettle_buffer_grow can wrap around, failing to allocate additional buffer space: if (buffer->size + length > buffer->alloc) There is another size computation in asn1_der_get_bignum which looks a bit suspicious as well. If 8 * i->length wraps around, then the max_bits restriction is not necessarily enforced: if (max_bits && (8 * i->length > (16 + max_bits))) This size computation in pgp_armor needs a guard against wraparound, too: unsigned text_size = BASE64_ENCODE_LENGTH(length) + BASE64_ENCODE_FINAL_LENGTH;