{"api_version":"1","generated_at":"2026-06-13T16:49:06+00:00","cve":"CVE-2026-43327","urls":{"html":"https://cve.report/CVE-2026-43327","api":"https://cve.report/api/cve/CVE-2026-43327.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-43327","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-43327"},"summary":{"title":"USB: dummy-hcd: Fix locking/synchronization error","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nUSB: dummy-hcd: Fix locking/synchronization error\n\nSyzbot testing was able to provoke an addressing exception and crash\nin the usb_gadget_udc_reset() routine in\ndrivers/usb/gadgets/udc/core.c, resulting from the fact that the\nroutine was called with a second (\"driver\") argument of NULL.  The bad\ncaller was set_link_state() in dummy_hcd.c, and the problem arose\nbecause of a race between a USB reset and driver unbind.\n\nThese sorts of races were not supposed to be possible; commit\n7dbd8f4cabd9 (\"USB: dummy-hcd: Fix erroneous synchronization change\"),\nalong with a few followup commits, was written specifically to prevent\nthem.  As it turns out, there are (at least) two errors remaining in\nthe code.  Another patch will address the second error; this one is\nconcerned with the first.\n\nThe error responsible for the syzbot crash occurred because the\nstop_activity() routine will sometimes drop and then re-acquire the\ndum->lock spinlock.  A call to stop_activity() occurs in\nset_link_state() when handling an emulated USB reset, after the test\nof dum->ints_enabled and before the increment of dum->callback_usage.\nThis allowed another thread (doing a driver unbind) to sneak in and\ngrab the spinlock, and then clear dum->ints_enabled and dum->driver.\nNormally this other thread would have to wait for dum->callback_usage\nto go down to 0 before it would clear dum->driver, but in this case it\ndidn't have to wait since dum->callback_usage had not yet been\nincremented.\n\nThe fix is to increment dum->callback_usage _before_ calling\nstop_activity() instead of after.  Then the thread doing the unbind\nwill not clear dum->driver until after the call to\nusb_gadget_udc_reset() safely returns and dum->callback_usage has been\ndecremented again.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-05-08 14:16:42","updated_at":"2026-05-15 18:05:56"},"problem_types":["CWE-667"],"metrics":[{"version":"3.1","source":"nvd@nist.gov","type":"Primary","score":"5.5","severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","data":{"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"}}],"references":[{"url":"https://git.kernel.org/stable/c/efbd9441f1e769a7aae1813d497cec09cbdff031","name":"https://git.kernel.org/stable/c/efbd9441f1e769a7aae1813d497cec09cbdff031","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/6350c7dd33ab481ef41c931a238361490c32d15c","name":"https://git.kernel.org/stable/c/6350c7dd33ab481ef41c931a238361490c32d15c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/616a63ff495df12863692ab3f9f7b84e3fa7a66d","name":"https://git.kernel.org/stable/c/616a63ff495df12863692ab3f9f7b84e3fa7a66d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/cc97fb5969177cccce2e23b31298df220fc7570d","name":"https://git.kernel.org/stable/c/cc97fb5969177cccce2e23b31298df220fc7570d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/218886b2ef2dea7627d3700ab0abaf4bf9d1161f","name":"https://git.kernel.org/stable/c/218886b2ef2dea7627d3700ab0abaf4bf9d1161f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/69ab97a693251d6a6093e630060a3c744fd58524","name":"https://git.kernel.org/stable/c/69ab97a693251d6a6093e630060a3c744fd58524","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/791966f85b439b261bf19865cf1c07c065ffb4b4","name":"https://git.kernel.org/stable/c/791966f85b439b261bf19865cf1c07c065ffb4b4","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/805b1833d6ed6da5086e610578a28e71bb54fbbb","name":"https://git.kernel.org/stable/c/805b1833d6ed6da5086e610578a28e71bb54fbbb","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-43327","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-43327","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 6350c7dd33ab481ef41c931a238361490c32d15c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 cc97fb5969177cccce2e23b31298df220fc7570d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 218886b2ef2dea7627d3700ab0abaf4bf9d1161f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 791966f85b439b261bf19865cf1c07c065ffb4b4 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 805b1833d6ed6da5086e610578a28e71bb54fbbb git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 efbd9441f1e769a7aae1813d497cec09cbdff031 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 69ab97a693251d6a6093e630060a3c744fd58524 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 616a63ff495df12863692ab3f9f7b84e3fa7a66d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7b416b9dac6ede26d4ca0c1a88b448b543623ff3 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 8590bc1da625dd4a589eac0fc3aa3cf4f400424d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a867d5b932ac4911d3f8a1e63505061b0c81f889 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e84b4a008365b7edbd842a063ae28d040a98db25 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected e39b17143a5b5aac81f066d455e5d3a9877eb3ae git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4f8ae1fcb0dfbb72a7678f81bf01fb7fc85c6715 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4.14","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 4.14 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.10.253 5.10.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.203 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.168 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.134 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.81 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.22 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.19.12 6.19.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[{"cve_year":"2026","cve_id":"43327","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"linux","cpe5":"linux_kernel","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"43327","cve":"CVE-2026-43327","epss":"0.000240000","percentile":"0.070360000","score_date":"2026-05-12","updated_at":"2026-05-13 00:11:53"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["drivers/usb/gadget/udc/dummy_hcd.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"6350c7dd33ab481ef41c931a238361490c32d15c","status":"affected","version":"7dbd8f4cabd96db5a50513de9d83a8105a5ffc81","versionType":"git"},{"lessThan":"cc97fb5969177cccce2e23b31298df220fc7570d","status":"affected","version":"7dbd8f4cabd96db5a50513de9d83a8105a5ffc81","versionType":"git"},{"lessThan":"218886b2ef2dea7627d3700ab0abaf4bf9d1161f","status":"affected","version":"7dbd8f4cabd96db5a50513de9d83a8105a5ffc81","versionType":"git"},{"lessThan":"791966f85b439b261bf19865cf1c07c065ffb4b4","status":"affected","version":"7dbd8f4cabd96db5a50513de9d83a8105a5ffc81","versionType":"git"},{"lessThan":"805b1833d6ed6da5086e610578a28e71bb54fbbb","status":"affected","version":"7dbd8f4cabd96db5a50513de9d83a8105a5ffc81","versionType":"git"},{"lessThan":"efbd9441f1e769a7aae1813d497cec09cbdff031","status":"affected","version":"7dbd8f4cabd96db5a50513de9d83a8105a5ffc81","versionType":"git"},{"lessThan":"69ab97a693251d6a6093e630060a3c744fd58524","status":"affected","version":"7dbd8f4cabd96db5a50513de9d83a8105a5ffc81","versionType":"git"},{"lessThan":"616a63ff495df12863692ab3f9f7b84e3fa7a66d","status":"affected","version":"7dbd8f4cabd96db5a50513de9d83a8105a5ffc81","versionType":"git"},{"status":"affected","version":"7b416b9dac6ede26d4ca0c1a88b448b543623ff3","versionType":"git"},{"status":"affected","version":"8590bc1da625dd4a589eac0fc3aa3cf4f400424d","versionType":"git"},{"status":"affected","version":"a867d5b932ac4911d3f8a1e63505061b0c81f889","versionType":"git"},{"status":"affected","version":"e84b4a008365b7edbd842a063ae28d040a98db25","versionType":"git"},{"status":"affected","version":"e39b17143a5b5aac81f066d455e5d3a9877eb3ae","versionType":"git"},{"status":"affected","version":"4f8ae1fcb0dfbb72a7678f81bf01fb7fc85c6715","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/usb/gadget/udc/dummy_hcd.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"4.14"},{"lessThan":"4.14","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.253","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.203","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.168","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.134","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.81","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.22","versionType":"semver"},{"lessThanOrEqual":"6.19.*","status":"unaffected","version":"6.19.12","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.0","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.253","versionStartIncluding":"4.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.203","versionStartIncluding":"4.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.168","versionStartIncluding":"4.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.134","versionStartIncluding":"4.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.81","versionStartIncluding":"4.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.22","versionStartIncluding":"4.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.19.12","versionStartIncluding":"4.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0","versionStartIncluding":"4.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.2.97","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16.52","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.1.46","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.4.92","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.9.55","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13.6","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nUSB: dummy-hcd: Fix locking/synchronization error\n\nSyzbot testing was able to provoke an addressing exception and crash\nin the usb_gadget_udc_reset() routine in\ndrivers/usb/gadgets/udc/core.c, resulting from the fact that the\nroutine was called with a second (\"driver\") argument of NULL.  The bad\ncaller was set_link_state() in dummy_hcd.c, and the problem arose\nbecause of a race between a USB reset and driver unbind.\n\nThese sorts of races were not supposed to be possible; commit\n7dbd8f4cabd9 (\"USB: dummy-hcd: Fix erroneous synchronization change\"),\nalong with a few followup commits, was written specifically to prevent\nthem.  As it turns out, there are (at least) two errors remaining in\nthe code.  Another patch will address the second error; this one is\nconcerned with the first.\n\nThe error responsible for the syzbot crash occurred because the\nstop_activity() routine will sometimes drop and then re-acquire the\ndum->lock spinlock.  A call to stop_activity() occurs in\nset_link_state() when handling an emulated USB reset, after the test\nof dum->ints_enabled and before the increment of dum->callback_usage.\nThis allowed another thread (doing a driver unbind) to sneak in and\ngrab the spinlock, and then clear dum->ints_enabled and dum->driver.\nNormally this other thread would have to wait for dum->callback_usage\nto go down to 0 before it would clear dum->driver, but in this case it\ndidn't have to wait since dum->callback_usage had not yet been\nincremented.\n\nThe fix is to increment dum->callback_usage _before_ calling\nstop_activity() instead of after.  Then the thread doing the unbind\nwill not clear dum->driver until after the call to\nusb_gadget_udc_reset() safely returns and dum->callback_usage has been\ndecremented again."}],"providerMetadata":{"dateUpdated":"2026-05-11T22:22:25.350Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/6350c7dd33ab481ef41c931a238361490c32d15c"},{"url":"https://git.kernel.org/stable/c/cc97fb5969177cccce2e23b31298df220fc7570d"},{"url":"https://git.kernel.org/stable/c/218886b2ef2dea7627d3700ab0abaf4bf9d1161f"},{"url":"https://git.kernel.org/stable/c/791966f85b439b261bf19865cf1c07c065ffb4b4"},{"url":"https://git.kernel.org/stable/c/805b1833d6ed6da5086e610578a28e71bb54fbbb"},{"url":"https://git.kernel.org/stable/c/efbd9441f1e769a7aae1813d497cec09cbdff031"},{"url":"https://git.kernel.org/stable/c/69ab97a693251d6a6093e630060a3c744fd58524"},{"url":"https://git.kernel.org/stable/c/616a63ff495df12863692ab3f9f7b84e3fa7a66d"}],"title":"USB: dummy-hcd: Fix locking/synchronization error","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-43327","datePublished":"2026-05-08T13:31:12.896Z","dateReserved":"2026-05-01T14:12:56.002Z","dateUpdated":"2026-05-11T22:22:25.350Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-05-08 14:16:42","lastModifiedDate":"2026-05-15 18:05:56","problem_types":["CWE-667"],"metrics":{"cvssMetricV31":[{"source":"nvd@nist.gov","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}]},"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.2.97","versionEndExcluding":"3.3","matchCriteriaId":"53EFF502-4DAC-47BB-88FE-57DAEB8A756F"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.16.52","versionEndExcluding":"3.17","matchCriteriaId":"05033BFD-A5E6-4D50-861A-0DFC71F68928"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.1.46","versionEndExcluding":"4.2","matchCriteriaId":"FD7B43DB-D99B-4203-84D2-00416A5FC499"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.4.92","versionEndExcluding":"4.5","matchCriteriaId":"0FC36FA2-9326-4373-A290-AD56F4EBE515"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.9.55","versionEndExcluding":"4.10","matchCriteriaId":"FF00429D-1E4D-4240-A156-ECC8962E597D"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14","versionEndExcluding":"5.10.253","matchCriteriaId":"7144BCBC-124B-49FA-8BCC-259910F77E5A"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"5.15.203","matchCriteriaId":"20DDB3E9-AABF-4107-ADB0-5362AA067045"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16","versionEndExcluding":"6.1.168","matchCriteriaId":"E2DDDCA1-6DAB-4018-B920-8F045DDD8D3B"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.6.134","matchCriteriaId":"F56F925B-BAF8-4F4B-B62F-1496AF19A307"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"6.12.81","matchCriteriaId":"6EF80433-B33B-43C5-8E64-0FA7B8DCE1BC"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"6.18.22","matchCriteriaId":"C9DF8BCE-36D3-475D-9D21-19E4F02F9029"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.19","versionEndExcluding":"6.19.12","matchCriteriaId":"0A2B9540-02D5-41B4-B16A-82AF66FD4F36"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*","matchCriteriaId":"F253B622-8837-4245-BCE5-A7BF8FC76A16"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*","matchCriteriaId":"4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*","matchCriteriaId":"F666C8D8-6538-46D4-B318-87610DE64C34"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*","matchCriteriaId":"02259FDA-961B-47BC-AE7F-93D7EC6E90C2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*","matchCriteriaId":"58A9FEFF-C040-420D-8F0A-BFDAAA1DF258"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*","matchCriteriaId":"1D2315C0-D46F-4F85-9754-F9E5E11374A6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*","matchCriteriaId":"512EE3A8-A590-4501-9A94-5D4B268D6138"}]}]}]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"43327","Ordinal":"1","Title":"USB: dummy-hcd: Fix locking/synchronization error","CVE":"CVE-2026-43327","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"43327","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nUSB: dummy-hcd: Fix locking/synchronization error\n\nSyzbot testing was able to provoke an addressing exception and crash\nin the usb_gadget_udc_reset() routine in\ndrivers/usb/gadgets/udc/core.c, resulting from the fact that the\nroutine was called with a second (\"driver\") argument of NULL.  The bad\ncaller was set_link_state() in dummy_hcd.c, and the problem arose\nbecause of a race between a USB reset and driver unbind.\n\nThese sorts of races were not supposed to be possible; commit\n7dbd8f4cabd9 (\"USB: dummy-hcd: Fix erroneous synchronization change\"),\nalong with a few followup commits, was written specifically to prevent\nthem.  As it turns out, there are (at least) two errors remaining in\nthe code.  Another patch will address the second error; this one is\nconcerned with the first.\n\nThe error responsible for the syzbot crash occurred because the\nstop_activity() routine will sometimes drop and then re-acquire the\ndum->lock spinlock.  A call to stop_activity() occurs in\nset_link_state() when handling an emulated USB reset, after the test\nof dum->ints_enabled and before the increment of dum->callback_usage.\nThis allowed another thread (doing a driver unbind) to sneak in and\ngrab the spinlock, and then clear dum->ints_enabled and dum->driver.\nNormally this other thread would have to wait for dum->callback_usage\nto go down to 0 before it would clear dum->driver, but in this case it\ndidn't have to wait since dum->callback_usage had not yet been\nincremented.\n\nThe fix is to increment dum->callback_usage _before_ calling\nstop_activity() instead of after.  Then the thread doing the unbind\nwill not clear dum->driver until after the call to\nusb_gadget_udc_reset() safely returns and dum->callback_usage has been\ndecremented again.","Type":"Description","Title":"USB: dummy-hcd: Fix locking/synchronization error"}]}}}