CVE-2021-47004

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> f2fs: fix to avoid touching checkpointed data in get_victim()<br /> <br /> In CP disabling mode, there are two issues when using LFS or SSR | AT_SSR<br /> mode to select victim:<br /> <br /> 1. LFS is set to find source section during GC, the victim should have<br /> no checkpointed data, since after GC, section could not be set free for<br /> reuse.<br /> <br /> Previously, we only check valid chpt blocks in current segment rather<br /> than section, fix it.<br /> <br /> 2. SSR | AT_SSR are set to find target segment for writes which can be<br /> fully filled by checkpointed and newly written blocks, we should never<br /> select such segment, otherwise it can cause panic or data corruption<br /> during allocation, potential case is described as below:<br /> <br /> a) target segment has &amp;#39;n&amp;#39; (n