CVE-2020-10768
A flaw was found in the Linux Kernel before 5.8-rc1 in the prctl() function, where it can be used to enable indirect branch speculation after it has been disabled. This call incorrectly reports it as being 'force disabled' when it is not and opens the system to Spectre v2 attacks. The highest threat from this vulnerability is to confidentiality.
02 / AFFECTED SOFTWARE
Affected packages
1 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In ib_prctl_set of bugs.c, there is a possible way to re-enable indirect branch speculation due to a permissions bypass. This could lead to local information disclosure via a Spectre v2 attack with no additional execution privileges needed. User interaction is not needed for exploitation.
A flaw was found in the Linux Kernel before 5.8-rc1 in the prctl() function, where it can be used to enable indirect branch speculation after it has been disabled. This call incorrectly reports it as being 'force disabled' when it is not and opens the system to Spectre v2 attacks. The highest threat from this vulnerability is to confidentiality.
05 / REFERENCES
Further evidence
- https://android.googlesource.com/kernel/common/+/4d8df8cbb9156b0a0ab3f802b80cb5db57acc0bf
- https://source.android.com/security/bulletin/2021-10-01
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-10768
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=4d8df8cbb9156b0a0ab3f802b80cb5db57acc0bf