UBUNTU-CVE-2020-12826
A signal access-control issue was discovered in the Linux kernel before 5.6.5, aka CID-7395ea4e65c2. Because exec_id in include/linux/sched.h is only 32 bits, an integer overflow can interfere with a do_notify_parent protection mechanism. A child process can send an arbitrary signal to a parent process in a different security domain. Exploitation limitations include the amount of elapsed time before an integer overflow occurs, and the lack of scenarios where signals to a parent process present a substantial operational threat.
02 / AFFECTED SOFTWARE
Affected packages
79 explicit affected versions
37 explicit affected versions
6 explicit affected versions
19 explicit affected versions
6 explicit affected versions
57 explicit affected versions
191 explicit affected versions
42 explicit affected versions
8 explicit affected versions
23 explicit affected versions
1 explicit affected versions
48 explicit affected versions
23 explicit affected versions
1 explicit affected versions
1 explicit affected versions
7 explicit affected versions
1 explicit affected versions
1 explicit affected versions
7 explicit affected versions
10 explicit affected versions
47 explicit affected versions
15 explicit affected versions
7 explicit affected versions
10 explicit affected versions
23 explicit affected versions
46 explicit affected versions
22 explicit affected versions
2 explicit affected versions
8 explicit affected versions
6 explicit affected versions
40 explicit affected versions
1 explicit affected versions
8 explicit affected versions
19 explicit affected versions
23 explicit affected versions
2 explicit affected versions
11 explicit affected versions
81 explicit affected versions
7 explicit affected versions
2 explicit affected versions
43 explicit affected versions
47 explicit affected versions
110 explicit affected versions
51 explicit affected versions
1 explicit affected versions
56 explicit affected versions
1 explicit affected versions
1 explicit affected versions
1 explicit affected versions
68 explicit affected versions
25 explicit affected versions
44 explicit affected versions
10 explicit affected versions
26 explicit affected versions
6 explicit affected versions
38 explicit affected versions
4 explicit affected versions
88 explicit affected versions
69 explicit affected versions
23 explicit affected versions
33 explicit affected versions
27 explicit affected versions
12 explicit affected versions
2 explicit affected versions
4 explicit affected versions
1 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
A signal access-control issue was discovered in the Linux kernel before 5.6.5, aka CID-7395ea4e65c2. Because exec_id in include/linux/sched.h is only 32 bits, an integer overflow can interfere with a do_notify_parent protection mechanism. A child process can send an arbitrary signal to a parent process in a different security domain. Exploitation limitations include the amount of elapsed time before an integer overflow occurs, and the lack of scenarios where signals to a parent process present a substantial operational threat.
05 / REFERENCES
Further evidence
- https://bugzilla.redhat.com/show_bug.cgi?id=1822077
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.6.5
- https://git.kernel.org/linus/d1e7fd6462ca9fc76650fbe6ca800e35b24267da
- https://github.com/torvalds/linux/commit/7395ea4e65c2a00d23185a3f63ad315756ba9cef
- https://lists.openwall.net/linux-kernel/2020/03/24/1803
- https://ubuntu.com/security/CVE-2020-12826
- https://ubuntu.com/security/notices/USN-4367-1
- https://ubuntu.com/security/notices/USN-4369-1
- https://ubuntu.com/security/notices/USN-4391-1
- https://www.cve.org/CVERecord?id=CVE-2020-12826
- https://www.openwall.com/lists/kernel-hardening/2020/03/25/1