vhost-scsi: reject feature changes after endpoint
Summary
| CVE | CVE-2026-74702 |
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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 | 2026-08-22 16:16:44 UTC |
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| Updated | 2026-08-22 16:16:44 UTC |
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| Description | In the Linux kernel, the following vulnerability has been resolved:
vhost-scsi: reject feature changes after endpoint
vhost_scsi_setup_vq_cmds() runs from VHOST_SCSI_SET_ENDPOINT and allocates
each command's protection scatterlist array (prot_sgl) according to the
acknowledged VIRTIO_SCSI_F_T10_PI bit. The command pools are not rebuilt
when VHOST_SET_FEATURES changes that bit later.
Although virtio feature bits must not change after feature negotiation,
vhost_scsi_set_features() currently accepts such a request after the
endpoint is active and updates acked_features. Enabling T10-PI after
endpoint setup therefore leaves prot_sgl NULL while the I/O path follows
the new feature bit.
For a 129-page protection payload, vhost_scsi_mapal() passes the missing
first chunk to sg_alloc_table_chained():
sg_alloc_table_chained(table, 129, first_chunk=NULL,
nents_first_chunk=inline_sg_cnt)
sg_pool_index() then hits:
BUG_ON(nents > SG_CHUNK_SIZE); /* 129 > 128 */
The kernel reported the following call trace and register state:
Call Trace:
<TASK>
? __sg_alloc_table+0x1d8/0x250
? __pfx_vhost_run_work_list+0x10/0x10 [vhost]
sg_alloc_table_chained+0x59/0xf0
? __pfx_sg_pool_alloc+0x10/0x10
? vhost_scsi_calc_sgls.constprop.0+0x43/0x60 [vhost_scsi]
vhost_scsi_handle_vq+0xf02/0x1700 [vhost_scsi]
? __pfx_vhost_scsi_handle_vq+0x10/0x10 [vhost_scsi]
vhost_scsi_handle_kick+0x37/0x50 [vhost_scsi]
vhost_run_work_list+0x8e/0xd0 [vhost]
vhost_task_fn+0xe1/0x210
ret_from_fork+0x348/0x540
</TASK>
RIP: 0010:0x4
CR2 = 0x4
RSP: 0018:ffffc90000dbf940 EFLAGS: 00010202
RAX: ffffffff82396810 RBX: ffff88811dc28b80 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000820 RDI: 0000000000000081
VHOST_F_LOG_ALL is a vhost-specific runtime feature and remains the only
exception.
Reject changes to any feature other than VHOST_F_LOG_ALL while the
endpoint is active. This preserves the existing runtime log toggle while
preventing feature-dependent command resources and data-path state from
becoming inconsistent. Userspace must clear the endpoint before changing
any other negotiated feature and set the endpoint up again afterward. |
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Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|
| CNA |
Linux |
Linux |
affected bf2d650391be508dd8b5e188b65ed32300cf3489 a06e4611d45518896fbff4f45d9581578b107e91 git |
Not specified |
| CNA |
Linux |
Linux |
affected bf2d650391be508dd8b5e188b65ed32300cf3489 9a3eb77a612f9d158e4d27df43677a014e9cfa55 git |
Not specified |
| CNA |
Linux |
Linux |
affected bf2d650391be508dd8b5e188b65ed32300cf3489 42bc45df5905e2b7dccb72adaf7730f66cfbe03f git |
Not specified |
| CNA |
Linux |
Linux |
affected 6.15 |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.15 semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 6.18.45 6.18.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.1.9 7.1.* semver |
Not specified |
| CNA |
Linux |
Linux |
unaffected 7.2 * original_commit_for_fix |
Not specified |
References
| Reference | Source | Link | Tags |
|---|
| git.kernel.org/stable/c/a06e4611d45518896fbff4f45d9581578b107e91 |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/42bc45df5905e2b7dccb72adaf7730f66cfbe03f |
416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
git.kernel.org |
|
| git.kernel.org/stable/c/9a3eb77a612f9d158e4d27df43677a014e9cfa55 |
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.