io_uring/cmd: fix iovec leak when the async cmd is not recycled
Summary
| CVE | CVE-2026-80811 |
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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 | 2026-09-04 16:18:08 UTC |
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| Updated | 2026-09-04 16:18:08 UTC |
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| Description | In the Linux kernel, the following vulnerability has been resolved:
io_uring/cmd: fix iovec leak when the async cmd is not recycled
An io_async_cmd carries an iovec array in ->vec.iovec, allocated when the
vec has to grow and kept across recycling through ctx->cmd_cache. On two
paths nothing frees it and io_clean_op()'s kfree(req->async_data) drops
the io_async_cmd without it.
io_req_uring_cleanup() clears the async data flags only when
io_alloc_cache_put() succeeds, and the cache holds IO_ALLOC_CACHE_MAX ==
128 entries, so once it is full the put fails and the vec is left behind.
An NVMe passthrough workload gets there without doing anything unusual:
nvme_uring_cmd_io() returns -EIOCBQUEUED, so the io_async_cmd stays
attached for the lifetime of the command and the live object count tracks
the queue depth. Above 128 the puts start failing.
->cleanup is the last chance to free an inherited vec, since
io_req_uring_cleanup() returns early for an io-wq issued command and is
not called at all for one completed without ever being issued. But
io_clean_op() calls ->cleanup only if REQ_F_NEED_CLEANUP is set, and for
uring_cmd that happens only where the vec has to grow, so a command
reusing a large enough cached vec never sets it. io_rw_alloc_async() and
io_msg_alloc_async() flag an inherited vec for exactly this reason;
io_uring_cmd_prep() does not.
Flag an inherited vec in io_uring_cmd_prep(), and free the vec when the
cache put fails, as io_req_rw_cleanup() does.
The leak is invisible under KASAN, where io_alloc_cache_vec_kasan() frees
the vec unconditionally. |
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Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|
| CNA |
Linux |
Linux |
affected 3a4689ac109f18f23ea0d0c1c79e055142796858 b6a768aa975b9ca81b92f028bdd975d1f8237894 git |
Not specified |
| CNA |
Linux |
Linux |
affected 3a4689ac109f18f23ea0d0c1c79e055142796858 b290de4d16d75b6c1ef42025b47f5d94eb1ec09f git |
Not specified |
| CNA |
Linux |
Linux |
affected 3a4689ac109f18f23ea0d0c1c79e055142796858 7068d3587a64a24943a7c9e232976da2c9e0e303 git |
Not specified |
| CNA |
Linux |
Linux |
affected 3a4689ac109f18f23ea0d0c1c79e055142796858 bb34ae5da3365699d53a756f4c96b6ea9f8ba0c1 git |
Not specified |
| CNA |
Linux |
Linux |
affected 6.15 |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.15 semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.18.47 6.18.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.1.11 7.1.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.2.1 7.2.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.3-rc1 * original_commit_for_fix |
Not specified |
References
| Reference | Source | Link | Tags |
|---|
| git.kernel.org/stable/c/b290de4d16d75b6c1ef42025b47f5d94eb1ec09f |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/bb34ae5da3365699d53a756f4c96b6ea9f8ba0c1 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/b6a768aa975b9ca81b92f028bdd975d1f8237894 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/7068d3587a64a24943a7c9e232976da2c9e0e303 |
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.