CVE-2021-46945

Summary

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

ext4: always panic when errors=panic is specified

Before commit 014c9caa29d3 ("ext4: make ext4_abort() use __ext4_error()"), the following series of commands would trigger a panic:

  1. mount /dev/sda -o ro,errors=panic test
  2. mount /dev/sda -o remount,abort test

After commit 014c9caa29d3, remounting a file system using the test mount option "abort" will no longer trigger a panic. This commit will restore the behaviour immediately before commit 014c9caa29d3. (However, note that the Linux kernel's behavior has not been consistent; some previous kernel versions, including 5.4 and 4.19 similarly did not panic after using the mount option "abort".)

This also makes a change to long-standing behaviour; namely, the following series commands will now cause a panic, when previously it did not:

  1. mount /dev/sda -o ro,errors=panic test
  2. echo test > /sys/fs/ext4/sda/trigger_fs_error

However, this makes ext4's behaviour much more consistent, so this is a good thing.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux014c9caa29d3a44e0de695c99ef18bec3e887d52 < 64e1eebe2131183174f4fbb6b1491355f96c6cdeaffected
LinuxLinux014c9caa29d3a44e0de695c99ef18bec3e887d52 < 1e9ea8f4637026b8e965128953f2da061ccae9c4affected
LinuxLinux014c9caa29d3a44e0de695c99ef18bec3e887d52 < ac2f7ca51b0929461ea49918f27c11b680f28995affected
LinuxLinux5.11affected
LinuxLinux0 < 5.11unaffected
LinuxLinux5.11.20 <= 5.11.*unaffected
LinuxLinux5.12.3 <= 5.12.*unaffected
LinuxLinux5.13 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

CVE Program Container

Additional References

References