CVE-2025-68358

/// Technical description

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

btrfs: fix racy bitfield write in btrfs_clear_space_info_full()

From the memory-barriers.txt document regarding memory barrier ordering

guarantees:

(*) These guarantees do not apply to bitfields, because compilers often

generate code to modify these using non-atomic read-modify-write

sequences. Do not attempt to use bitfields to synchronize parallel

algorithms.

(*) Even in cases where bitfields are protected by locks, all fields

in a given bitfield must be protected by one lock. If two fields

in a given bitfield are protected by different locks, the compiler's

non-atomic read-modify-write sequences can cause an update to one

field to corrupt the value of an adjacent field.

btrfs_space_info has a bitfield sharing an underlying word consisting of

the fields full, chunk_alloc, and flush:

struct btrfs_space_info {

struct btrfs_fs_info * fs_info; /* 0

/// 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