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

What is CVE-2022-49408?

CVE-2022-49408 is a medium-severity denial of service vulnerability in Linux kernel, published on 26 Feb 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official 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

Weakness: CWE-401

Which versions are affected by CVE-2022-49408?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2022-49408?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2022-49408 being exploited?

There is no known exploitation of CVE-2022-49408 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2022-49408, GHSA-j793-r5pf-7w34, UBUNTU-CVE-2022-49408.