CVE-2020-10766
A logic bug flaw was found in Linux kernel before 5.8-rc1 in the implementation of SSBD. A bug in the logic handling allows an attacker with a local account to disable SSBD protection during a context switch when additional speculative execution mitigations are in place. This issue was introduced when the per task/process conditional STIPB switching was added on top of the existing SSBD switching. 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 __speculation_ctrl_update of process.c, there is a possible way to disable Speculative Store Bypass Disable due to a logic error, which allows for side channel information disclosure. This could lead to local information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation.
A logic bug flaw was found in Linux kernel before 5.8-rc1 in the implementation of SSBD. A bug in the logic handling allows an attacker with a local account to disable SSBD protection during a context switch when additional speculative execution mitigations are in place. This issue was introduced when the per task/process conditional STIPB switching was added on top of the existing SSBD switching. The highest threat from this vulnerability is to confidentiality.
05 / REFERENCES
Further evidence
- https://android.googlesource.com/kernel/common/+/dbbe2ad02e9df26e372f38cc3e70dab9222c832e
- https://source.android.com/security/bulletin/2021-01-01
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-10766
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=dbbe2ad02e9df26e372f38cc3e70dab9222c832e