CVE-2024-50102
Nov. 12, 2024, 3:08 p.m.
Tags
CVSS Score
Products Impacted
Vendor | Product | Versions |
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linux |
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Description
In the Linux kernel, the following vulnerability has been resolved: x86: fix user address masking non-canonical speculation issue It turns out that AMD has a "Meltdown Lite(tm)" issue with non-canonical accesses in kernel space. And so using just the high bit to decide whether an access is in user space or kernel space ends up with the good old "leak speculative data" if you have the right gadget using the result: CVE-2020-12965 “Transient Execution of Non-Canonical Accesses“ Now, the kernel surrounds the access with a STAC/CLAC pair, and those instructions end up serializing execution on older Zen architectures, which closes the speculation window. But that was true only up until Zen 5, which renames the AC bit [1]. That improves performance of STAC/CLAC a lot, but also means that the speculation window is now open. Note that this affects not just the new address masking, but also the regular valid_user_address() check used by access_ok(), and the asm version of the sign bit check in the get_user() helpers. It does not affect put_user() or clear_user() variants, since there's no speculative result to be used in a gadget for those operations.
Weaknesses
CWE-203
Observable Discrepancy
The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor, which exposes security-relevant information about the state of the product, such as whether a particular operation was successful or not.
CWE ID: 203Date
Published: Nov. 5, 2024, 6:15 p.m.
Last Modified: Nov. 12, 2024, 3:08 p.m.
Status : Analyzed
CVE has been recently published to the CVE List and has been received by the NVD.
More infoSource
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CPEs
Type | Vendor | Product | Version | Update | Edition | Language | Software Edition | Target Software | Target Hardware | Other Information |
---|---|---|---|---|---|---|---|---|---|---|
o | linux | linux_kernel | / | / | / | / | / | / | / | / |
o | linux | linux_kernel | 6.12 | rc1 | / | / | / | / | / | / |
o | linux | linux_kernel | 6.12 | rc2 | / | / | / | / | / | / |
o | linux | linux_kernel | 6.12 | rc3 | / | / | / | / | / | / |
o | linux | linux_kernel | 6.12 | rc4 | / | / | / | / | / | / |
CVSS Data
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
NONE
Availability Impact
NONE
Base Score
Exploitability Score
Impact Score
Base Severity
MEDIUMCVSS Vector String
The CVSS vector string provides an in-depth view of the vulnerability metrics.
View Vector StringCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N