CVE-2021-46945 Information

Feb 29, 2024 cve

Description

In the Linux kernel the following vulnerability has been resolved:

ext4: always panic when errors=panic is specified

Before commit 014c9caa29d3 (xt4: make ext4_abort() use __ext4_error()) the following series of commands would trigger a panic:

  1. mount /dev/sda -o roerrors=panic test
  2. mount /dev/sda -o remountabort test

After commit 014c9caa29d3 remounting a file system using the test mount option bort\ 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 bort.)

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 roerrors=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.

Reference

https://git.kernel.org/stable/c/64e1eebe2131183174f4fbb6b1491355f96c6cde https://git.kernel.org/stable/c/1e9ea8f4637026b8e965128953f2da061ccae9c4 https://git.kernel.org/stable/c/ac2f7ca51b0929461ea49918f27c11b680f28995

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