CVE-2026-98083

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

btrfs: fix transaction use-after-free in raid stripe insertion

If allocation of a RAID stripe extent fails, btrfs_insert_one_raid_extent() aborts and ends the transaction before returning -ENOMEM.

btrfs_finish_one_ordered(), the production caller through btrfs_insert_raid_extent(), still owns the transaction handle. It handles the error by aborting the transaction and then reaches the common exit path, which ends the transaction again.

The premature end can free the handle and drop its transaction reference. Transaction cleanup can then free the transaction before the callers second abort accesses the handle and transaction, resulting in use-after-free.

Keep the abort at the failure site, but let the callers common exit path end the transaction once, after it has finished using both objects.

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/089d9c45ea49ffffe55a8fe08d0ce2536626e90a
• https://git.kernel.org/stable/c/2fbfd02bdfe12b20bd3cc7a3190fb32e3f7072f5
• https://git.kernel.org/stable/c/a8813a923f9e43f788b357fb55c35f7f6ed6f98c
• https://git.kernel.org/stable/c/b185bdf30313e213fa1c887fe22fc3d513c061d9
• https://git.kernel.org/stable/c/b7b94923b3b5774d85a2a7c8d6eb9e3e0ef66685