CVE-2026-89644
Last modified
CVE-2026-89644 is a vulnerability of currently unknown severity. In the Linux kernel, the following vulnerability has been resolved: btrfs: fix extent map leak in NOCOW direct I/O write btrfs_dio_iomap_begin() calls btrfs_get_extent(), which returns an extent map reference that must be dropped on all exit paths. For direct writes into a NOCOW range, btrfs_get_blocks_direct_write() keeps using that extent map and asks btrfs_create_dio_extent() to allocate the ordered extent. If that fails, for example because btrfs_alloc_ordered_extent() fails, the function returns the error without dropping the input extent map. EPSS estimates a 0.17% chance of exploitation in the next 30 days.
Description
In the Linux kernel, the following vulnerability has been resolved: btrfs: fix extent map leak in NOCOW direct I/O write btrfs_dio_iomap_begin() calls btrfs_get_extent(), which returns an extent map reference that must be dropped on all exit paths. For direct writes into a NOCOW range, btrfs_get_blocks_direct_write() keeps using that extent map and asks btrfs_create_dio_extent() to allocate the ordered extent. If that fails, for example because btrfs_alloc_ordered_extent() fails, the function returns the error without dropping the input extent map. The PREALLOC path avoided this by dropping the input extent map before replacing it with the newly created one. Check the error from btrfs_create_dio_extent() before replacing the map and drop the input extent map on failure.
Metrics
Affected Software
Source: CNA advisory (CVE.org). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | >= 5f9a8a51d8b95505d8de8b7191ae2ed8c504d4af, < b7c873765875645b11503f94c9bae2ca80127375; >= 5f9a8a51d8b95505d8de8b7191ae2ed8c504d4af, < f42efd634c0ae7ba0ce2fc5e30e291b0803b0ae2; >= 5f9a8a51d8b95505d8de8b7191ae2ed8c504d4af, < 05a1a816eef8b3e4332620a64fc8cf45c4eb5c0d; >= 5f9a8a51d8b95505d8de8b7191ae2ed8c504d4af, < 3f950867c307c5413d628a153ac44915bd117ffd |
| Linux | Linux | 4.7 |
References
Timeline
- Published
- Last Modified
- Status
- Received
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