{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "descriptions": [
            {
               "lang": "en",
               "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring: fix shared sqpoll cancellation hangs\n\n[  736.982891] INFO: task iou-sqp-4294:4295 blocked for more than 122 seconds.\n[  736.982897] Call Trace:\n[  736.982901]  schedule+0x68/0xe0\n[  736.982903]  io_uring_cancel_sqpoll+0xdb/0x110\n[  736.982908]  io_sqpoll_cancel_cb+0x24/0x30\n[  736.982911]  io_run_task_work_head+0x28/0x50\n[  736.982913]  io_sq_thread+0x4e3/0x720\n\nWe call io_uring_cancel_sqpoll() one by one for each ctx either in\nsq_thread() itself or via task works, and it's intended to cancel all\nrequests of a specified context. However the function uses per-task\ncounters to track the number of inflight requests, so it counts more\nrequests than available via currect io_uring ctx and goes to sleep for\nthem to appear (e.g. from IRQ), that will never happen.\n\nCancel a bit more than before, i.e. all ctxs that share sqpoll\nand continue to use shared counters. Don't forget that we should not\nremove ctx from the list before running that task_work sqpoll-cancel,\notherwise the function wouldn't be able to find the context and will\nhang."
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "fs/io_uring.c"
               ],
               "versions": [
                  {
                     "version": "37d1e2e3642e",
                     "lessThan": "cb5e0b3d0f99",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "37d1e2e3642e",
                     "lessThan": "734551df6f9b",
                     "status": "affected",
                     "versionType": "git"
                  }
               ]
            },
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "affected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "fs/io_uring.c"
               ],
               "versions": [
                  {
                     "version": "5.12",
                     "status": "affected"
                  },
                  {
                     "version": "0",
                     "lessThan": "5.12",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.12.3",
                     "lessThanOrEqual": "5.12.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.13",
                     "lessThanOrEqual": "*",
                     "status": "unaffected",
                     "versionType": "original_commit_for_fix"
                  }
               ]
            }
         ],
         "references": [
            {
               "url": "https://git.kernel.org/stable/c/cb5e0b3d0f993a6268c1a2c7ede2f9aa0c17ef68"
            },
            {
               "url": "https://git.kernel.org/stable/c/734551df6f9bedfbefcd113ede665945e9de0b99"
            }
         ],
         "title": "io_uring: fix shared sqpoll cancellation hangs",
         "x_generator": {
            "engine": "bippy-a5840b7849dd"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2021-46942",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}