UBUNTU-CVE-2021-28688
The fix for XSA-365 includes initialization of pointers such that subsequent cleanup code wouldn't use uninitialized or stale values. This initialization went too far and may under certain conditions also overwrite pointers which are in need of cleaning up. The lack of cleanup would result in leaking persistent grants. The leak in turn would prevent fully cleaning up after a respective guest has died, leaving around zombie domains. All Linux versions having the fix for XSA-365 applied are vulnerable. XSA-365 was classified to affect versions back to at least 3.11.
02 / AFFECTED SOFTWARE
Affected packages
50 explicit affected versions
6 explicit affected versions
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57 explicit affected versions
191 explicit affected versions
64 explicit affected versions
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44 explicit affected versions
17 explicit affected versions
74 explicit affected versions
23 explicit affected versions
71 explicit affected versions
1 explicit affected versions
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18 explicit affected versions
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12 explicit affected versions
1 explicit affected versions
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19 explicit affected versions
10 explicit affected versions
137 explicit affected versions
13 explicit affected versions
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1 explicit affected versions
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1 explicit affected versions
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13 explicit affected versions
58 explicit affected versions
1 explicit affected versions
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10 explicit affected versions
43 explicit affected versions
11 explicit affected versions
66 explicit affected versions
28 explicit affected versions
2 explicit affected versions
61 explicit affected versions
24 explicit affected versions
1 explicit affected versions
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1 explicit affected versions
1 explicit affected versions
23 explicit affected versions
18 explicit affected versions
1 explicit affected versions
19 explicit affected versions
1 explicit affected versions
20 explicit affected versions
8 explicit affected versions
17 explicit affected versions
44 explicit affected versions
16 explicit affected versions
13 explicit affected versions
38 explicit affected versions
9 explicit affected versions
114 explicit affected versions
18 explicit affected versions
49 explicit affected versions
2 explicit affected versions
74 explicit affected versions
51 explicit affected versions
11 explicit affected versions
42 explicit affected versions
17 explicit affected versions
43 explicit affected versions
1 explicit affected versions
92 explicit affected versions
89 explicit affected versions
12 explicit affected versions
21 explicit affected versions
4 explicit affected versions
8 explicit affected versions
1 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
The fix for XSA-365 includes initialization of pointers such that subsequent cleanup code wouldn't use uninitialized or stale values. This initialization went too far and may under certain conditions also overwrite pointers which are in need of cleaning up. The lack of cleanup would result in leaking persistent grants. The leak in turn would prevent fully cleaning up after a respective guest has died, leaving around zombie domains. All Linux versions having the fix for XSA-365 applied are vulnerable. XSA-365 was classified to affect versions back to at least 3.11.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/a846738f8c3788d846ed1f587270d2f2e3d32432
- https://ubuntu.com/security/CVE-2021-28688
- https://ubuntu.com/security/notices/USN-4946-1
- https://ubuntu.com/security/notices/USN-4948-1
- https://ubuntu.com/security/notices/USN-4982-1
- https://ubuntu.com/security/notices/USN-4984-1
- https://ubuntu.com/security/notices/USN-5343-1
- https://www.cve.org/CVERecord?id=CVE-2021-28688
- https://xenbits.xen.org/xsa/advisory-371.html