CVE-2025-38370

Technical Description

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

btrfs: fix failure to rebuild free space tree using multiple transactions

If we are rebuilding a free space tree, while modifying the free space

tree we may need to allocate a new metadata block group.

If we end up using multiple transactions for the rebuild, when we call

btrfs_end_transaction() we enter btrfs_create_pending_block_groups()

which calls add_block_group_free_space() to add items to the free space

tree for the block group.

Then later during the free space tree rebuild, at

btrfs_rebuild_free_space_tree(), we may find such new block groups

and call populate_free_space_tree() for them, which fails with -EEXIST

because there are already items in the free space tree. Then we abort the

transaction with -EEXIST at btrfs_rebuild_free_space_tree().

Notice that we say "may find" the new block groups because a new block

group may be inserted in the block groups rbtree, which is being iterated

by the rebuild proces

Remediation

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. 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.

Affected Products

References