An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a denial of service or possibly gain privileges because of missing memory barriers in read-write unlock paths. The read-write unlock paths don\'t contain a memory barrier. On Arm, this means a processor is allowed to re-order the memory access with the preceding ones. In other words, the unlock may be seen by another processor before all the memory accesses within the critical section. As a consequence, it may be possible to have a writer executing a critical section at the same time as readers or another writer. In other words, many of the assumptions (e.g., a variable cannot be modified after a check) in the critical sections are not safe anymore. The read-write locks are used in hypercalls (such as grant-table ones), so a malicious guest could exploit the race. For instance, there is a small window where Xen can leak memory if XENMAPSPACE_grant_table is used concurrently. A malicious guest may be able to leak memory, or cause a hypervisor crash resulting in a Denial of Service (DoS). Information leak and privilege escalation cannot be excluded.
Find out more about CVE-2020-11739 from the MITRE-CVE dictionary and NIST NVD
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| Product Name | Status | Defect | Fixed | Downloads |
|---|---|---|---|---|
| Linux | ||||
| Wind River Linux LTS 17 | Not Vulnerable | -- | -- | -- |
| Wind River Linux 8 | Not Vulnerable | -- | -- | -- |
| Wind River Linux 9 | Not Vulnerable | -- | -- | -- |
| Wind River Linux 7 | Not Vulnerable | -- | -- | -- |
| Wind River Linux LTS 21 | Not Vulnerable | -- | -- | -- |
| Wind River Linux LTS 22 | Not Vulnerable | -- | -- | -- |
| Wind River Linux LTS 18 | Not Vulnerable | -- | -- | -- |
| Wind River Linux LTS 19 | Not Vulnerable | -- | -- | -- |
| Wind River Linux CD release | Not Vulnerable | -- | -- | -- |
| Wind River Linux 6 | Not Vulnerable | -- | -- | -- |
| Wind River Linux LTS 23 | Not Vulnerable | -- | -- | -- |
| VxWorks | ||||
| VxWorks 7 | Not Vulnerable | -- | -- | -- |
| VxWorks 6.9 | Not Vulnerable | -- | -- | -- |
| Helix Virtualization Platform Cert Edition | ||||
| Helix Virtualization Platform Cert Edition | Not Vulnerable | -- | -- | -- |
| Product Name | Status | Defect | Fixed | Downloads |
|---|
