CVE-2023-52569: btrfs: remove BUG() after failure to insert delayed dir index item

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-03-02 · updated 2026-06-17
Weakness: CWE-617

Description

In the Linux kernel, the following vulnerability has been resolved: btrfs: remove BUG() after failure to insert delayed dir index item Instead of calling BUG() when we fail to insert a delayed dir index item into the delayed node's tree, we can just release all the resources we have allocated/acquired before and return the error to the caller. This is fine because all existing call chains undo anything they have done before calling btrfs_insert_delayed_dir_index() or BUG_ON (when creating pending snapshots in the transaction commit path). So remove the BUG() call and do proper error handling. This relates to a syzbot report linked below, but does not fix it because it only prevents hitting a BUG(), it does not fix the issue where somehow we attempt to use twice the same index number for different index items.

Affected products

Linux kernel: before 6.1.56; from 6.2 before 6.5.6; 6.6-rc1 — fixed in 6.1.56, 6.5.6

How to fix

Upgrade to a fixed version: Linux kernel 6.1.56, 6.5.6. Check the vendor advisory for mitigations.

References

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