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.
The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
| Link | Tags |
|---|---|
| https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.6.5 | third party advisory release notes |
| https://www.openwall.com/lists/kernel-hardening/2020/03/25/1 | mailing list patch exploit third party advisory |
| https://lists.openwall.net/linux-kernel/2020/03/24/1803 | mailing list patch exploit third party advisory |
| https://github.com/torvalds/linux/commit/7395ea4e65c2a00d23185a3f63ad315756ba9cef | third party advisory patch |
| https://bugzilla.redhat.com/show_bug.cgi?id=1822077 | issue tracking third party advisory patch |
| https://usn.ubuntu.com/4367-1/ | third party advisory vendor advisory |
| https://usn.ubuntu.com/4369-1/ | vendor advisory |
| https://security.netapp.com/advisory/ntap-20200608-0001/ | |
| https://lists.debian.org/debian-lts-announce/2020/06/msg00011.html | mailing list |
| https://lists.debian.org/debian-lts-announce/2020/06/msg00013.html | mailing list |
| https://usn.ubuntu.com/4391-1/ | vendor advisory |