{"id":"CVE-2025-39999","state":"PUBLISHED","title":"blk-mq: fix blk_mq_tags double free while nr_requests grown","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nblk-mq: fix blk_mq_tags double free while nr_requests grown\n\nIn the case user trigger tags grow by queue sysfs attribute nr_requests,\nhctx->sched_tags will be freed directly and replaced with a new\nallocated tags, see blk_mq_tag_update_depth().\n\nThe problem is that hctx->sched_tags is from elevator->et->tags, while\net->tags is still the freed tags, hence later elevator exit will try to\nfree the tags again, causing kernel panic.\n\nFix this problem by replacing et->tags with new allocated tags as well.\n\nNoted there are still some long term problems that will require some\nrefactor to be fixed thoroughly[1].\n\n[1] https://lore.kernel.org/all/20250815080216.410665-1-yukuai1@huaweicloud.com/","publishedAt":"2025-10-15T07:58:23.038Z","updatedAt":"2026-05-23T16:01:13.466Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"58567d8e95c096ad234963df90a2ca518901f4b6","status":"affected","lessThan":"8faee580d63bc2a54a59dcdb7f9ce4de29384fec","versionType":"git"},{"version":"f5a6604f7a4405450e4a1f54e5430f47290c500f","status":"affected","lessThan":"392b1d64911f4de8887fe8b68299fa8bd6e5b923","versionType":"git"},{"version":"f5a6604f7a4405450e4a1f54e5430f47290c500f","status":"affected","lessThan":"ba28afbd9eff2a6370f23ef4e6a036ab0cfda409","versionType":"git"},{"version":"6.16.4","status":"affected","lessThan":"6.16.11","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["block/blk-mq-tag.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.17","versionType":"semver"},{"version":"6.16.11","status":"unaffected","lessThanOrEqual":"6.16.*","versionType":"semver"},{"version":"6.17.1","status":"unaffected","lessThanOrEqual":"6.17.*","versionType":"semver"},{"version":"6.18","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["block/blk-mq-tag.c"]}],"references":["https://git.kernel.org/stable/c/8faee580d63bc2a54a59dcdb7f9ce4de29384fec","https://git.kernel.org/stable/c/392b1d64911f4de8887fe8b68299fa8bd6e5b923","https://git.kernel.org/stable/c/ba28afbd9eff2a6370f23ef4e6a036ab0cfda409"],"weaknesses":[],"ingestedAt":"2026-10-29T20:09:09.358Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/39xxx/CVE-2025-39999.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-39999","state":"PUBLISHED","datePublished":"2025-10-15T07:58:23.038Z","dateUpdated":"2026-05-23T16:01:13.466Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-04-16T07:20:57.151Z"},"containers":{"cna":{"title":"blk-mq: fix blk_mq_tags double free while nr_requests grown","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nblk-mq: fix blk_mq_tags double free while nr_requests grown\n\nIn the case user trigger tags grow by queue sysfs attribute nr_requests,\nhctx->sched_tags will be freed directly and replaced with a new\nallocated tags, see blk_mq_tag_update_depth().\n\nThe problem is that hctx->sched_tags is from elevator->et->tags, while\net->tags is still the freed tags, hence later elevator exit will try to\nfree the tags again, causing kernel panic.\n\nFix this problem by replacing et->tags with new allocated tags as well.\n\nNoted there are still some long term problems that will require some\nrefactor to be fixed thoroughly[1].\n\n[1] https://lore.kernel.org/all/20250815080216.410665-1-yukuai1@huaweicloud.com/"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"58567d8e95c096ad234963df90a2ca518901f4b6","status":"affected","lessThan":"8faee580d63bc2a54a59dcdb7f9ce4de29384fec","versionType":"git"},{"version":"f5a6604f7a4405450e4a1f54e5430f47290c500f","status":"affected","lessThan":"392b1d64911f4de8887fe8b68299fa8bd6e5b923","versionType":"git"},{"version":"f5a6604f7a4405450e4a1f54e5430f47290c500f","status":"affected","lessThan":"ba28afbd9eff2a6370f23ef4e6a036ab0cfda409","versionType":"git"},{"version":"6.16.4","status":"affected","lessThan":"6.16.11","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["block/blk-mq-tag.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.17","versionType":"semver"},{"version":"6.16.11","status":"unaffected","lessThanOrEqual":"6.16.*","versionType":"semver"},{"version":"6.17.1","status":"unaffected","lessThanOrEqual":"6.17.*","versionType":"semver"},{"version":"6.18","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["block/blk-mq-tag.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/8faee580d63bc2a54a59dcdb7f9ce4de29384fec"},{"url":"https://git.kernel.org/stable/c/392b1d64911f4de8887fe8b68299fa8bd6e5b923"},{"url":"https://git.kernel.org/stable/c/ba28afbd9eff2a6370f23ef4e6a036ab0cfda409"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-23T16:01:13.466Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16.4","versionEndExcluding":"6.16.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.17","versionEndExcluding":"6.17.1"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.17","versionEndExcluding":"6.18"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}