Answer in brief
CVE-2021-46989 records a High severity (CVSS 7.1) vulnerability in hfsplus: prevent corruption in shrinking truncate. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=31651c607151f1034cfb57e5a78678bea54c362b <52dde855663e5db824af51db39b5757d2ef3e28a || >=31651c607151f1034cfb57e5a78678bea54c362b <c451a6bafb5f422197d31536f82116aed132b72c || >=31651c607151f1034cfb57e5a78678bea54c362b <adbd8a2a8cc05d9e501f93e5c95c59307874cc99 || >=31651c607151f1034cfb57e5a78678bea54c362b <c477f62db1a0c0ecaa60a29713006ceeeb04b685 || >=31651c607151f1034cfb57e5a78678bea54c362b <97314e45aa1223a42d60256a62c5d9af54baf446 || >=31651c607151f1034cfb57e5a78678bea54c362b <c3187cf32216313fb316084efac4dab3a8459b1d | 52dde855663e5db824af51db39b5757d2ef3e28a, c451a6bafb5f422197d31536f82116aed132b72c, adbd8a2a8cc05d9e501f93e5c95c59307874cc99, c477f62db1a0c0ecaa60a29713006ceeeb04b685, 97314e45aa1223a42d60256a62c5d9af54baf446, c3187cf32216313fb316084efac4dab3a8459b1d |
| Linux/Linuxgeneric | 4.19 | Not reported |
Published upstream
Feb 28, 2024
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 4, 2026
In the Linux kernel, the following vulnerability has been resolved: hfsplus: prevent corruption in shrinking truncate I believe there are some issues introduced by commit 31651c607151 ("hfsplus: avoid deadlock on file truncation") HFS+ has extent records which always contains 8 extents. In case the first extent record in catalog file gets full, new ones are allocated from extents overflow file. In case shrinking truncate happens to middle of an extent record which locates in extents overflow file, the logic in hfsplus_file_truncate() was changed so that call to hfs_brec_remove() is not guarded any more. Right action would be just freeing the extents that exceed the new size inside extent record by calling hfsplus_free_extents(), and then check if the whole extent record should be removed. However since the guard (blk_cnt > start) is now after the call to hfs_brec_remove(), this has unfortunate effect that the last matching extent record is removed unconditionally. To reproduce this issue, create a file which has at least 10 extents, and then perform shrinking truncate into middle of the last extent record, so that the number of remaining extents is not under or divisible by 8. This causes the last extent record (8 extents) to be removed totally instead of truncating into middle of it. Thus this causes corruption, and lost data. Fix for this is simply checking if the new truncated end is below the start of this extent record, making it safe to remove the full extent record. However call to hfs_brec_remove() can't be moved to it's previous place since we're dropping ->tree_lock and it can cause a race condition and the cached info being invalidated possibly corrupting the node data. Another issue is related to this one. When entering into the block (blk_cnt > start) we are not holding the ->tree_lock. We break out from the loop not holding the lock, but hfs_find_exit() does unlock it. Not sure if it's possible for someone else to take the lock under our feet, but it can cause hard to debug errors and premature unlocking. Even if there's no real risk of it, the locking should still always be kept in balance. Thus taking the lock now just before the check.
Quoted source text, attributed separately from HOL analysis.