CVE-2022-49408: ext4: fix memory leak in parse_apply_sb_mount_options()

CVE-2022-49408: ext4: fix memory leak in parse_apply_sb_mount_options()

[Greg Kroah-Hartman]

Description
===========

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

ext4: fix memory leak in parse_apply_sb_mount_options()

If processing the on-disk mount options fails after any memory was
allocated in the ext4_fs_context, e.g. s_qf_names, then this memory is
leaked.  Fix this by calling ext4_fc_free() instead of kfree() directly.

Reproducer:

    mkfs.ext4 -F /dev/vdc
    tune2fs /dev/vdc -E mount_opts=usrjquota=file
    echo clear > /sys/kernel/debug/kmemleak
    mount /dev/vdc /vdc
    echo scan > /sys/kernel/debug/kmemleak
    sleep 5
    echo scan > /sys/kernel/debug/kmemleak
    cat /sys/kernel/debug/kmemleak

The Linux kernel CVE team has assigned CVE-2022-49408 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 5.17 with commit 7edfd85b1ffd36593011dec96ab395912a340418 and fixed in 5.17.14 with commit 9ea3e6168948189cec31d0678d2b55b395f88491
	Issue introduced in 5.17 with commit 7edfd85b1ffd36593011dec96ab395912a340418 and fixed in 5.18.3 with commit f92ded66e9d0aa20b883a2a5183973abc8f41815
	Issue introduced in 5.17 with commit 7edfd85b1ffd36593011dec96ab395912a340418 and fixed in 5.19 with commit c069db76ed7b681c69159f44be96d2137e9ca989

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2022-49408
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	fs/ext4/super.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/9ea3e6168948189cec31d0678d2b55b395f88491
	https://git.kernel.org/stable/c/f92ded66e9d0aa20b883a2a5183973abc8f41815
	https://git.kernel.org/stable/c/c069db76ed7b681c69159f44be96d2137e9ca989