CVE-2022-49001 Information

Description

In the Linux kernel the following vulnerability has been resolved:

riscv: fix race when vmap stack overflow

Currently when detecting vmap stack overflow riscv firstly switches to the so called shadow stack then use this shadow stack to call the get_overflow_stack() to get the overflow stack. However there’s a race here if two or more harts use the same shadow stack at the same time.

To solve this race we introduce spin_shadow_stack atomic var which will be swap between its own address and 0 in atomic way when the var is set it means the shadow_stack is being used; when the var is cleared it means the shadow_stack isn’t being used.

[Palmer: Add AQ to the swap and also some comments.]

CVSS Vector

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Reference

https://git.kernel.org/stable/c/ac00301adb19df54f2eae1efc4bad7447c0156ce https://git.kernel.org/stable/c/879fabc5a95401d9bce357e4b1d24ae4a360a81f https://git.kernel.org/stable/c/7e1864332fbc1b993659eab7974da9fe8bf8c128

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

7.0