title: ext4: always panic when errors=panic is specified
description: 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:
{
product: Linux
vendor: Linux
defaultStatus: unaffected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 014c9caa29d3, lessThan: 64e1eebe2131, status: affected, versionType: git
version: 014c9caa29d3, lessThan: 1e9ea8f46370, status: affected, versionType: git
version: 014c9caa29d3, lessThan: ac2f7ca51b09, status: affected, versionType: git
}
{
product: Linux
vendor: Linux
defaultStatus: affected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 5.11, status: affected
version: 0, lessThan: 5.11, status: unaffected, versionType: custom
version: 5.11.20, lessThanOrEqual: 5.11.*, status: unaffected, versionType: custom
version: 5.12.3, lessThanOrEqual: 5.12.*, status: unaffected, versionType: custom
version: 5.13, lessThanOrEqual: *, status: unaffected, versionType: original_commit_for_fix
}
