It was reported  that a crafted diff file (attached) can make patch to eat memory and later segfault.
Upstream commit that fixes this:
Created attachment 983284 [details]
Created patch tracking bugs for this issue:
Affects: fedora-all [bug 1184491]
patch-2.7.3-1.fc21 has been pushed to the Fedora 21 stable repository. If problems still persist, please make note of it in this bug report.
patch-2.7.5-1.fc20 has been pushed to the Fedora 20 stable repository. If problems still persist, please make note of it in this bug report.
Red Hat Product Security has rated this issue as having Low security impact. This issue is not currently planned to be addressed in future updates. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.