CVE-2022-49327

/// Technical description

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

bcache: avoid journal no-space deadlock by reserving 1 journal bucket

The journal no-space deadlock was reported time to time. Such deadlock

can happen in the following situation.

When all journal buckets are fully filled by active jset with heavy

write I/O load, the cache set registration (after a reboot) will load

all active jsets and inserting them into the btree again (which is

called journal replay). If a journaled bkey is inserted into a btree

node and results btree node split, new journal request might be

triggered. For example, the btree grows one more level after the node

split, then the root node record in cache device super block will be

upgrade by bch_journal_meta() from bch_btree_set_root(). But there is no

space in journal buckets, the journal replay has to wait for new journal

bucket to be reclaimed after at least one journal bucket replayed. This

is one example that how the journal no-space deadlock

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References