{"cve":"CVE-2026-74702","nvd":{"published":"2026-08-22T16:16:44.873","modified":"2026-10-14T13:10:00.187","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nvhost-scsi: reject feature changes after endpoint\n\nvhost_scsi_setup_vq_cmds() runs from VHOST_SCSI_SET_ENDPOINT and allocates\neach command's protection scatterlist array (prot_sgl) according to the\nacknowledged VIRTIO_SCSI_F_T10_PI bit.  The command pools are not rebuilt\nwhen VHOST_SET_FEATURES changes that bit later.\n\nAlthough virtio feature bits must not change after feature negotiation,\nvhost_scsi_set_features() currently accepts such a request after the\nendpoint is active and updates acked_features.  Enabling T10-PI after\nendpoint setup therefore leaves prot_sgl NULL while the I/O path follows\nthe new feature bit.\n\nFor a 129-page protection payload, vhost_scsi_mapal() passes the missing\nfirst chunk to sg_alloc_table_chained():\n\n  sg_alloc_table_chained(table, 129, first_chunk=NULL,\n                         nents_first_chunk=inline_sg_cnt)\n\nsg_pool_index() then hits:\n\n  BUG_ON(nents > SG_CHUNK_SIZE);   /* 129 > 128 */\n\nThe kernel reported the following call trace and register state:\n\n  Call Trace:\n   <TASK>\n   ? __sg_alloc_table+0x1d8/0x250\n   ? __pfx_vhost_run_work_list+0x10/0x10 [vhost]\n   sg_alloc_table_chained+0x59/0xf0\n   ? __pfx_sg_pool_alloc+0x10/0x10\n   ? vhost_scsi_calc_sgls.constprop.0+0x43/0x60 [vhost_scsi]\n   vhost_scsi_handle_vq+0xf02/0x1700 [vhost_scsi]\n   ? __pfx_vhost_scsi_handle_vq+0x10/0x10 [vhost_scsi]\n   vhost_scsi_handle_kick+0x37/0x50 [vhost_scsi]\n   vhost_run_work_list+0x8e/0xd0 [vhost]\n   vhost_task_fn+0xe1/0x210\n   ret_from_fork+0x348/0x540\n   </TASK>\n\n  RIP: 0010:0x4\n  CR2 = 0x4\n  RSP: 0018:ffffc90000dbf940 EFLAGS: 00010202\n  RAX: ffffffff82396810 RBX: ffff88811dc28b80 RCX: 0000000000000000\n  RDX: 0000000000000000 RSI: 0000000000000820 RDI: 0000000000000081\n\nVHOST_F_LOG_ALL is a vhost-specific runtime feature and remains the only\nexception.\n\nReject changes to any feature other than VHOST_F_LOG_ALL while the\nendpoint is active.  This preserves the existing runtime log toggle while\npreventing feature-dependent command resources and data-path state from\nbecoming inconsistent.  Userspace must clear the endpoint before changing\nany other negotiated feature and set the endpoint up again afterward.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","score":8.8},"cwes":[],"references":["https://git.kernel.org/stable/c/42bc45df5905e2b7dccb72adaf7730f66cfbe03f","https://git.kernel.org/stable/c/9a3eb77a612f9d158e4d27df43677a014e9cfa55","https://git.kernel.org/stable/c/a06e4611d45518896fbff4f45d9581578b107e91"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:49:38.260478770+00:00"},"epss":{"cve":"CVE-2026-74702","score":0.00173,"percentile":0.06727,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}