CVE-2022-49001

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> riscv: fix race when vmap stack overflow<br /> <br /> Currently, when detecting vmap stack overflow, riscv firstly switches<br /> to the so called shadow stack, then use this shadow stack to call the<br /> get_overflow_stack() to get the overflow stack. However, there&amp;#39;s<br /> a race here if two or more harts use the same shadow stack at the same<br /> time.<br /> <br /> To solve this race, we introduce spin_shadow_stack atomic var, which<br /> will be swap between its own address and 0 in atomic way, when the<br /> var is set, it means the shadow_stack is being used; when the var<br /> is cleared, it means the shadow_stack isn&amp;#39;t being used.<br /> <br /> [Palmer: Add AQ to the swap, and also some comments.]