CVE-2025-71161

Summary

In the Linux kernel, the following vulnerability has been resolved:

dm-verity: disable recursive forward error correction

There are two problems with the recursive correction:

  1. It may cause denial-of-service. In fec_read_bufs, there is a loop that has 253 iterations. For each iteration, we may call verity_hash_for_block recursively. There is a limit of 4 nested recursions - that means that there may be at most 253^4 (4 billion) iterations. Red Hat QE team actually created an image that pushes dm-verity to this limit - and this image just makes the udev-worker process get stuck in the 'D' state.

  2. It doesn't work. In fec_read_bufs we store data into the variable "fio->bufs", but fio bufs is shared between recursive invocations, if "verity_hash_for_block" invoked correction recursively, it would overwrite partially filled fio->bufs.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxa739ff3f543afbb4a041c16cd0182c8e8d366e70 < 8b821ca892cfeeaf0bedc9fc72717294f67144d5affected
LinuxLinuxa739ff3f543afbb4a041c16cd0182c8e8d366e70 < e227d2b229c7529bd98d348efc55262ccf24ab35affected
LinuxLinuxa739ff3f543afbb4a041c16cd0182c8e8d366e70 < 897d9006e75f46f8bd7df78faa424327ae6a4bcfaffected
LinuxLinuxa739ff3f543afbb4a041c16cd0182c8e8d366e70 < 4220cb37406915c926c0e4a3dbab77cd9cceeb1eaffected
LinuxLinuxa739ff3f543afbb4a041c16cd0182c8e8d366e70 < 232948cf600fba69aff36b25d85ef91a73a35756affected
LinuxLinuxa739ff3f543afbb4a041c16cd0182c8e8d366e70 < d9f3e47d3fae0c101d9094bc956ed24e7a0ee801affected
LinuxLinux4.5affected
LinuxLinux0 < 4.5unaffected
LinuxLinux5.15.209 <= 5.15.*unaffected
LinuxLinux6.1.167 <= 6.1.*unaffected
LinuxLinux6.6.130 <= 6.6.*unaffected
LinuxLinux6.12.78 <= 6.12.*unaffected
LinuxLinux6.18.6 <= 6.18.*unaffected
LinuxLinux6.19 <= *unaffected

Weaknesses

References