CVE-2022-49761

/// Technical description

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

btrfs: always report error in run_one_delayed_ref()

Currently we have a btrfs_debug() for run_one_delayed_ref() failure, but

if end users hit such problem, there will be no chance that

btrfs_debug() is enabled. This can lead to very little useful info for

debugging.

This patch will:

- Add extra info for error reporting

Including:

* logical bytenr

* num_bytes

* type

* action

* ref_mod

- Replace the btrfs_debug() with btrfs_err()

- Move the error reporting into run_one_delayed_ref()

This is to avoid use-after-free, the @node can be freed in the caller.

This error should only be triggered at most once.

As if run_one_delayed_ref() failed, we trigger the error message, then

causing the call chain to error out:

btrfs_run_delayed_refs()

`- btrfs_run_delayed_refs()

`- btrfs_run_delayed_refs_for_head()

`- run_one_delayed_ref()

And we will abort the current transaction in btrfs_run_delayed_refs(

/// 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