CVE-2022-49761 Information

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(). If we have to run delayed refs for the abort transaction run_one_delayed_ref() will just cleanup the refs and do nothing thus no new error messages would be output.

Reference

https://git.kernel.org/stable/c/18bd1c9c02e64a3567f90c83c2c8b855531c8098 https://git.kernel.org/stable/c/39f501d68ec1ed5cd5c66ac6ec2a7131c517bb92 https://git.kernel.org/stable/c/853ffa1511b058c79a4c9bb1407b3b20ce311792 https://git.kernel.org/stable/c/fdb4a70bb768d2a87890409597529ad81cb3de8a