CVE-2025-22113 ext4: avoid journaling sb update on error if journal is destroying

What is CVE-2025-22113?

CVE-2025-22113 is a medium-severity denial of service vulnerability in Linux kernel, published on 16 Apr 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: avoid journaling sb update on error if journal is destroying

Presently we always BUG_ON if trying to start a transaction on a journal marked with JBD2_UNMOUNT, since this should never happen. However, while ltp running stress tests, it was observed that in case of some error handling paths, it is possible for update_super_work to start a transaction after the journal is destroyed eg:

(umount) ext4_kill_sb kill_block_super generic_shutdown_super sync_filesystem /* commits all txns */ evict_inodes /* might start a new txn */ ext4_put_super flush_work(&sbi->s_sb_upd_work) /* flush the workqueue */ jbd2_journal_destroy journal_kill_thread journal->j_flags |= JBD2_UNMOUNT; jbd2_journal_commit_transaction jbd2_journal_get_descriptor_buffer jbd2_journal_bmap ext4_journal_bmap ext4_map_blocks ... ext4_inode_error ext4_handle_error schedule_work(&sbi->s_sb_upd_work)

/* work queue kicks in */ update_super_work jbd2_journal_start start_this_handle BUG_ON(journal->j_flags & JBD2_UNMOUNT)

Hence, introduce a new mount flag to indicate journal is destroying and only do a journaled (and deferred) update of sb if this flag is not set. Otherwise, just fallback to an un-journaled commit.

Further, in the journal destroy path, we have the following sequence:

1. Set mount flag indicating journal is destroying 2. force a commit and wait for it 3. flush pending sb updates

This sequence is important as it ensures that, after this point, there is no sb update that might be journaled so it is safe to update the sb outside the journal. (To avoid race discussed in 2d01ddc86606)

Also, we don't need a similar check in ext4_grp_locked_error since it is only called from mballoc and AFAICT it would be always valid to schedule work here.

Which versions are affected by CVE-2025-22113?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2025-22113?

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-2025-22113 being exploited?

There is no known exploitation of CVE-2025-22113 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 AZL-62538, AZL-69605, BELL-CVE-2025-22113, DEBIAN-CVE-2025-22113, GHSA-2gxm-8qch-c9vg, ROOT-OS-DEBIAN-12-CVE-2025-22113 and 4 more.