15
May
CVE-2020-12826 is assigned to track the problem with Linux kernel which I’ve described in my previous post:
CVE MITRE described the problem pretty accurately:
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. |
RedHat tracks this issue here:
https://bugzilla.redhat.com/show_bug.cgi?id=1822077
Debian here:
https://security-tracker.debian.org/tracker/CVE-2020-12826
Fix can be found here:
https://github.com/torvalds/linux/commit/7395ea4e65c2a00d23185a3f63ad315756ba9cef
What is interesting, the story of insufficient restriction of the exit signals might not be ended 😉
In short, the following patch reintroduces the same problem:
Best regards,
Adam