An issue was discovered in illumos before f859e7171bb5db34321e45585839c6c3200ebb90, OmniOS Community Edition r151038, OpenIndiana Hipster 2021.04, and SmartOS 20210923. A local unprivileged user can cause a deadlock and kernel panic via crafted rename and rmdir calls on tmpfs filesystems. Oracle Solaris 10 and 11 is also affected.

The x86-64 kernel system-call functionality in Xen 4.1.2 and earlier, as used in Citrix XenServer 6.0.2 and earlier and other products; Oracle Solaris 11 and earlier; illumos before r13724; Joyent SmartOS before 20120614T184600Z; FreeBSD before 9.0-RELEASE-p3; NetBSD 6.0 Beta and earlier; Microsoft Windows Server 2008 R2 and R2 SP1 and Windows 7 Gold and SP1; and possibly other operating systems, when running on an Intel processor, incorrectly uses the sysret path in cases where a certain address is not a canonical address, which allows local users to gain privileges via a crafted application. NOTE: because this issue is due to incorrect use of the Intel specification, it should have been split into separate identifiers; however, there was some value in preserving the original mapping of the multi-codebase coordinated-disclosure effort to a single identifier.