CVE-2021-47066

async_xor: increase src_offs when dropping destination page

Description

In the Linux kernel, the following vulnerability has been resolved: async_xor: increase src_offs when dropping destination page Now we support sharing one page if PAGE_SIZE is not equal stripe size. To support this, it needs to support calculating xor value with different offsets for each r5dev. One offset array is used to record those offsets. In RMW mode, parity page is used as a source page. It sets ASYNC_TX_XOR_DROP_DST before calculating xor value in ops_run_prexor5. So it needs to add src_list and src_offs at the same time. Now it only needs src_list. So the xor value which is calculated is wrong. It can cause data corruption problem. I can reproduce this problem 100% on a POWER8 machine. The steps are: mdadm -CR /dev/md0 -l5 -n3 /dev/sdb1 /dev/sdc1 /dev/sdd1 --size=3G mkfs.xfs /dev/md0 mount /dev/md0 /mnt/test mount: /mnt/test: mount(2) system call failed: Structure needs cleaning.

5.5

CVSS

Severity: Medium

CVSS 3.1 •

EPSS 0.02%

Affected: Linux Linux

References

Link	Tags
https://git.kernel.org/stable/c/cab2e8e5997b592fdb7d02cf2387b4b8e3057174	patch
https://git.kernel.org/stable/c/29ffa50f33de824b5491f8239c88c4a0efdd03af	patch
https://git.kernel.org/stable/c/53f8208e11abd6dde9480dfcb97fecdb1bc2ac18	patch
https://git.kernel.org/stable/c/ceaf2966ab082bbc4d26516f97b3ca8a676e2af8	patch

Frequently Asked Questions

What is the severity of CVE-2021-47066?: CVE-2021-47066 has been scored as a medium severity vulnerability.
How to fix CVE-2021-47066?: To fix CVE-2021-47066, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-47066 being actively exploited in the wild?: As for now, there are no information to confirm that CVE-2021-47066 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-47066?: CVE-2021-47066 affects Linux Linux, Linux Linux.

This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.