{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-43327","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-05-01T14:12:56.002Z","datePublished":"2026-05-08T13:31:12.896Z","dateUpdated":"2026-05-11T22:22:25.350Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-05-11T22:22:25.350Z"},"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."}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/usb/gadget/udc/dummy_hcd.c"],"versions":[{"version":"7dbd8f4cabd96db5a50513de9d83a8105a5ffc81","lessThan":"6350c7dd33ab481ef41c931a238361490c32d15c","status":"affected","versionType":"git"},{"version":"7dbd8f4cabd96db5a50513de9d83a8105a5ffc81","lessThan":"cc97fb5969177cccce2e23b31298df220fc7570d","status":"affected","versionType":"git"},{"version":"7dbd8f4cabd96db5a50513de9d83a8105a5ffc81","lessThan":"218886b2ef2dea7627d3700ab0abaf4bf9d1161f","status":"affected","versionType":"git"},{"version":"7dbd8f4cabd96db5a50513de9d83a8105a5ffc81","lessThan":"791966f85b439b261bf19865cf1c07c065ffb4b4","status":"affected","versionType":"git"},{"version":"7dbd8f4cabd96db5a50513de9d83a8105a5ffc81","lessThan":"805b1833d6ed6da5086e610578a28e71bb54fbbb","status":"affected","versionType":"git"},{"version":"7dbd8f4cabd96db5a50513de9d83a8105a5ffc81","lessThan":"efbd9441f1e769a7aae1813d497cec09cbdff031","status":"affected","versionType":"git"},{"version":"7dbd8f4cabd96db5a50513de9d83a8105a5ffc81","lessThan":"69ab97a693251d6a6093e630060a3c744fd58524","status":"affected","versionType":"git"},{"version":"7dbd8f4cabd96db5a50513de9d83a8105a5ffc81","lessThan":"616a63ff495df12863692ab3f9f7b84e3fa7a66d","status":"affected","versionType":"git"},{"version":"7b416b9dac6ede26d4ca0c1a88b448b543623ff3","status":"affected","versionType":"git"},{"version":"8590bc1da625dd4a589eac0fc3aa3cf4f400424d","status":"affected","versionType":"git"},{"version":"a867d5b932ac4911d3f8a1e63505061b0c81f889","status":"affected","versionType":"git"},{"version":"e84b4a008365b7edbd842a063ae28d040a98db25","status":"affected","versionType":"git"},{"version":"e39b17143a5b5aac81f066d455e5d3a9877eb3ae","status":"affected","versionType":"git"},{"version":"4f8ae1fcb0dfbb72a7678f81bf01fb7fc85c6715","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/usb/gadget/udc/dummy_hcd.c"],"versions":[{"version":"4.14","status":"affected"},{"version":"0","lessThan":"4.14","status":"unaffected","versionType":"semver"},{"version":"5.10.253","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.203","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.168","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.134","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.81","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.22","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"6.19.12","lessThanOrEqual":"6.19.*","status":"unaffected","versionType":"semver"},{"version":"7.0","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14","versionEndExcluding":"5.10.253"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14","versionEndExcluding":"5.15.203"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14","versionEndExcluding":"6.1.168"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14","versionEndExcluding":"6.6.134"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14","versionEndExcluding":"6.12.81"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14","versionEndExcluding":"6.18.22"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14","versionEndExcluding":"6.19.12"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.14","versionEndExcluding":"7.0"},{"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"}]}]}],"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"}}}}