Date: Tue, 05 Jul 2022 12:04:23 +0000 From: Xen.org security team <security@....org> To: xen-announce@...ts.xen.org, xen-devel@...ts.xen.org, xen-users@...ts.xen.org, oss-security@...ts.openwall.com CC: Xen.org security team <security-team-members@....org> Subject: Xen Security Advisory 406 v3 (CVE-2022-33744) - Arm guests can cause Dom0 DoS via PV devices -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Xen Security Advisory CVE-2022-33744 / XSA-406 version 3 Arm guests can cause Dom0 DoS via PV devices UPDATES IN VERSION 3 ==================== Public release. ISSUE DESCRIPTION ================= When mapping pages of guests on Arm, dom0 is using an rbtree to keep track of the foreign mappings. Updating of that rbtree is not always done completely with the related lock held, resulting in a small race window, which can be used by unprivileged guests via PV devices to cause inconsistencies of the rbtree. These inconsistencies can lead to Denial of Service (DoS) of dom0, e.g. by causing crashes or the inability to perform further mappings of other guests' memory pages. IMPACT ====== A guest performing multiple I/Os of PV devices in parallel can cause DoS of dom0 and thus of the complete host. VULNERABLE SYSTEMS ================== Only Arm systems (32-bit and 64-bit) are vulnerable. Dom0 Linux versions 3.13 - 5.18 are vulnerable. X86 systems are not vulnerable. MITIGATION ========== There is no mitigation available. CREDITS ======= This issue was discovered by Oleksandr Tyshchenko of EPAM. RESOLUTION ========== Applying the appropriate attached patch resolves this issue. Note that patches for released versions are generally prepared to apply to the stable branches, and may not apply cleanly to the most recent release tarball. Downstreams are encouraged to update to the tip of the stable branch before applying these patches. xsa406-linux.patch Linux 3.13 - 5.19-rc $ sha256sum xsa406* 7a789f564b3365cade6e95d549dbbd5a8b7b5e53d09bc5a463c77dfefd5a4182 xsa406-linux.patch $ DEPLOYMENT DURING EMBARGO ========================= Deployment of the patches and/or mitigations described above (or others which are substantially similar) is permitted during the embargo, even on public-facing systems with untrusted guest users and administrators. But: Distribution of updated software is prohibited (except to other members of the predisclosure list). Predisclosure list members who wish to deploy significantly different patches and/or mitigations, please contact the Xen Project Security Team. (Note: this during-embargo deployment notice is retained in post-embargo publicly released Xen Project advisories, even though it is then no longer applicable. This is to enable the community to have oversight of the Xen Project Security Team's decisionmaking.) For more information about permissible uses of embargoed information, consult the Xen Project community's agreed Security Policy: http://www.xenproject.org/security-policy.html -----BEGIN PGP SIGNATURE----- iQFABAEBCAAqFiEEI+MiLBRfRHX6gGCng/4UyVfoK9kFAmLEFgEMHHBncEB4ZW4u b3JnAAoJEIP+FMlX6CvZwJUIAJSrSYNMQE4jo1sJFKjEJ3cHy6CymbJC94JSm2Tf HzeMlwd7NQF3Sc2HSWQoCSI+0TiRb6bJpfZASsbL/E3b6zcm3+VxwS7HVUtvHXhN HJYRUMN9vckUkGwWDYbgveI7uie9P7gpjwi5CEXxQf4NO9Oloyk2J5bijktzbBN2 9FIZ7zFuiSRwGtr2WRaozCSzgg4EGiPRc5eMCFMP+K0P+oRvpkE52wWo/ZOPzW8T xocUIcvQK335ib04OCS3oqJZrRNwrvX6Vn+CifXac2WHR9tQ24VnTq1iYRrVD+5x kxpg4IuiNc2eD8lZCLnKEUDUj6LzWvgxKoxXgJFKXlESb0A= =57so -----END PGP SIGNATURE----- Download attachment "xsa406-linux.patch" of type "application/octet-stream" (2561 bytes)
Powered by blists - more mailing lists
Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.