netfs: Fix missing alloc tagging of direct mempool allocations
Summary
| CVE | CVE-2026-98920 |
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| State | PUBLISHED |
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| Assigner | Linux |
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| Source Priority | CVE Program / NVD first with legacy fallback |
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| Published | 2026-10-23 13:17:12 UTC |
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| Updated | 2026-10-23 13:17:12 UTC |
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| Description | In the Linux kernel, the following vulnerability has been resolved:
netfs: Fix missing alloc tagging of direct mempool allocations
Commit 1d78d56c43ef ("netfs: Fix folio_queue ENOMEM in writeback by
adding a mempool") added a mempool for the folio_queues and made the
request, subrequest and folio_queue allocations distinguish between
writeback and everything else. Writeback is part of memory reclaim
and must not fail due to ENOMEM, so it allocates under GFP_NOFS
through mempool_alloc(), which may dip into the pool's reserve and,
if that runs empty, wait for elements to be returned. The
GFP_KERNEL paths, which can return -ENOMEM to their callers, invoke
the pool's ->alloc() callback directly instead.
The direct call, however, skips the alloc_hooks() wrapper that the
mempool_alloc() macro provides. The pool callbacks, mempool_alloc_slab()
and mempool_kmalloc(), call kmem_cache_alloc_noprof() and kmalloc_noprof()
and rely on current->alloc_tag having been set by the caller. With
CONFIG_MEM_ALLOC_PROFILING_DEBUG=y this leads to
current->alloc_tag not set
WARNING: ./include/linux/alloc_tag.h:161 at __alloc_tagging_slab_alloc_hook
alloc_tag was not set
WARNING: ./include/linux/alloc_tag.h:166 at __alloc_tagging_slab_free_hook
at allocation and free time respectively, as reported when reading
files on a CIFS mount. The allocations are also missing from
/proc/allocinfo.
Wrap the direct ->alloc() invocations in alloc_hooks() with a new
mempool_alloc_noreserve() helper in include/linux/mempool.h, next to
the other alloc_hooks()-wrapped macros such as mempool_alloc(). The
GFP_KERNEL paths keep their failable allocation semantics, they just
get tagged now. |
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Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|
| CNA |
Linux |
Linux |
affected 15ed8a9b7c63e9171f5139a6aaa1ffb61809861f 5c03da745171485fd181f17b69213464f6d05f3d git |
Not specified |
| CNA |
Linux |
Linux |
affected 1d78d56c43ef3768183e8370e7367b162700e049 37a2042748bc880df03ff8315db86ed82991fbb8 git |
Not specified |
| CNA |
Linux |
Linux |
affected 1d78d56c43ef3768183e8370e7367b162700e049 b78b728e21c32ec4c330b299f657fb1eb02dffc2 git |
Not specified |
| CNA |
Linux |
Linux |
affected b343252d6f536203dd0660f676190dcbf6d2ecdc git |
Not specified |
| CNA |
Linux |
Linux |
affected 3f6d7f8a5416d852648d15a05e895f1195ee8a85 git |
Not specified |
| CNA |
Linux |
Linux |
affected 6.12.114 6.13 semver |
Not specified |
| CNA |
Linux |
Linux |
affected 7.1.8 7.2 semver |
Not specified |
| CNA |
Linux |
Linux |
affected 7.2 |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.2 semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.2.9 7.2.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.3 * original_commit_for_fix |
Not specified |
References
| Reference | Source | Link | Tags |
|---|
| git.kernel.org/stable/c/5c03da745171485fd181f17b69213464f6d05f3d |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/37a2042748bc880df03ff8315db86ed82991fbb8 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/b78b728e21c32ec4c330b299f657fb1eb02dffc2 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| CVE Program record |
CVE.ORG |
www.cve.org |
canonical |
| NVD vulnerability detail |
NVD |
nvd.nist.gov |
canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.