{"id":"CVE-2026-64331","state":"PUBLISHED","title":"usbip: vudc: fix NULL deref in vep_dequeue()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nusbip: vudc: fix NULL deref in vep_dequeue()\n\nvep_alloc_request() wasn't initializing vrequest->udc, so cancellations\non the FunctionFS AIO path were arriving in vep_dequeue without a valid\nUDC reference.\n\nSince vrequest->udc is never actually properly used anywhere, we opt to\nremove it, and update vep_dequeue to obtain a reference to the udc with\nep_to_vudc(), consistent with the other vep_ ops.\n\nAFAICT this bug has existed for ~10 years. Seems that nobody has really\nstressed the FunctionFS AIO path on usbip's vudc.\n\nI tested this fix in a QEMU aarch64 guest driving FunctionFS endpoints\nvia AIO. Before the fix, running `usbip attach` from the host would\ncause the guest to oops with the following backtrace:\n\nCall trace:\n vep_dequeue+0x1c/0xe4 (P)\n usb_ep_dequeue+0x14/0x20\n ffs_aio_cancel+0x24/0x34\n __arm64_sys_io_cancel+0xb0/0x124\n do_el0_svc+0x68/0x100\n el0_svc+0x18/0x5c\n el0t_64_sync_handler+0x98/0xdc\n el0t_64_sync+0x154/0x158","publishedAt":"2026-07-25T08:49:58.370Z","updatedAt":"2026-08-17T04:53:33.891Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"b6a0ca11186759ad7045d68a5447b1e89f658384","status":"affected","lessThan":"9858c91d9ee6a13c45311569039413729fc9b757","versionType":"git"},{"version":"b6a0ca11186759ad7045d68a5447b1e89f658384","status":"affected","lessThan":"1226293ec9bed3d4cc5b05eeeb811d315ca51652","versionType":"git"},{"version":"b6a0ca11186759ad7045d68a5447b1e89f658384","status":"affected","lessThan":"3750f75f29f99c0223601e2ee73ad084adec47bd","versionType":"git"},{"version":"b6a0ca11186759ad7045d68a5447b1e89f658384","status":"affected","lessThan":"d0ebf9cc7c2ddf95a7cfc654b940bdacb7edde97","versionType":"git"},{"version":"b6a0ca11186759ad7045d68a5447b1e89f658384","status":"affected","lessThan":"0025276175fbbe0dcbf3f84d090b0adee769e9d9","versionType":"git"},{"version":"b6a0ca11186759ad7045d68a5447b1e89f658384","status":"affected","lessThan":"347b59e9f96719d89b6ef555d02a18ada1a5846f","versionType":"git"},{"version":"b6a0ca11186759ad7045d68a5447b1e89f658384","status":"affected","lessThan":"0443e4416aa1ee97748d1ed904eaf3352c60045e","versionType":"git"},{"version":"b6a0ca11186759ad7045d68a5447b1e89f658384","status":"affected","lessThan":"c5371e0b91b24159a3ebaa61e70b0980bcf03c0a","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/usb/usbip/vudc.h","drivers/usb/usbip/vudc_dev.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.7","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.7","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.96","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/usb/usbip/vudc.h","drivers/usb/usbip/vudc_dev.c"]}],"references":["https://git.kernel.org/stable/c/9858c91d9ee6a13c45311569039413729fc9b757","https://git.kernel.org/stable/c/1226293ec9bed3d4cc5b05eeeb811d315ca51652","https://git.kernel.org/stable/c/3750f75f29f99c0223601e2ee73ad084adec47bd","https://git.kernel.org/stable/c/d0ebf9cc7c2ddf95a7cfc654b940bdacb7edde97","https://git.kernel.org/stable/c/0025276175fbbe0dcbf3f84d090b0adee769e9d9","https://git.kernel.org/stable/c/347b59e9f96719d89b6ef555d02a18ada1a5846f","https://git.kernel.org/stable/c/0443e4416aa1ee97748d1ed904eaf3352c60045e","https://git.kernel.org/stable/c/c5371e0b91b24159a3ebaa61e70b0980bcf03c0a"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64331.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64331","state":"PUBLISHED","datePublished":"2026-07-25T08:49:58.370Z","dateUpdated":"2026-08-17T04:53:33.891Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T15:36:31.781Z"},"containers":{"cna":{"title":"usbip: vudc: fix NULL deref in vep_dequeue()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nusbip: vudc: fix NULL deref in vep_dequeue()\n\nvep_alloc_request() wasn't initializing vrequest->udc, so cancellations\non the FunctionFS AIO path were arriving in vep_dequeue without a valid\nUDC reference.\n\nSince vrequest->udc is never actually properly used anywhere, we opt to\nremove it, and update vep_dequeue to obtain a reference to the udc with\nep_to_vudc(), consistent with the other vep_ ops.\n\nAFAICT this bug has existed for ~10 years. Seems that nobody has really\nstressed the FunctionFS AIO path on usbip's vudc.\n\nI tested this fix in a QEMU aarch64 guest driving FunctionFS endpoints\nvia AIO. Before the fix, running `usbip attach` from the host would\ncause the guest to oops with the following backtrace:\n\nCall trace:\n vep_dequeue+0x1c/0xe4 (P)\n usb_ep_dequeue+0x14/0x20\n ffs_aio_cancel+0x24/0x34\n __arm64_sys_io_cancel+0xb0/0x124\n do_el0_svc+0x68/0x100\n el0_svc+0x18/0x5c\n el0t_64_sync_handler+0x98/0xdc\n el0t_64_sync+0x154/0x158"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"b6a0ca11186759ad7045d68a5447b1e89f658384","status":"affected","lessThan":"9858c91d9ee6a13c45311569039413729fc9b757","versionType":"git"},{"version":"b6a0ca11186759ad7045d68a5447b1e89f658384","status":"affected","lessThan":"1226293ec9bed3d4cc5b05eeeb811d315ca51652","versionType":"git"},{"version":"b6a0ca11186759ad7045d68a5447b1e89f658384","status":"affected","lessThan":"3750f75f29f99c0223601e2ee73ad084adec47bd","versionType":"git"},{"version":"b6a0ca11186759ad7045d68a5447b1e89f658384","status":"affected","lessThan":"d0ebf9cc7c2ddf95a7cfc654b940bdacb7edde97","versionType":"git"},{"version":"b6a0ca11186759ad7045d68a5447b1e89f658384","status":"affected","lessThan":"0025276175fbbe0dcbf3f84d090b0adee769e9d9","versionType":"git"},{"version":"b6a0ca11186759ad7045d68a5447b1e89f658384","status":"affected","lessThan":"347b59e9f96719d89b6ef555d02a18ada1a5846f","versionType":"git"},{"version":"b6a0ca11186759ad7045d68a5447b1e89f658384","status":"affected","lessThan":"0443e4416aa1ee97748d1ed904eaf3352c60045e","versionType":"git"},{"version":"b6a0ca11186759ad7045d68a5447b1e89f658384","status":"affected","lessThan":"c5371e0b91b24159a3ebaa61e70b0980bcf03c0a","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/usb/usbip/vudc.h","drivers/usb/usbip/vudc_dev.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.7","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.7","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.96","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/usb/usbip/vudc.h","drivers/usb/usbip/vudc_dev.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/9858c91d9ee6a13c45311569039413729fc9b757"},{"url":"https://git.kernel.org/stable/c/1226293ec9bed3d4cc5b05eeeb811d315ca51652"},{"url":"https://git.kernel.org/stable/c/3750f75f29f99c0223601e2ee73ad084adec47bd"},{"url":"https://git.kernel.org/stable/c/d0ebf9cc7c2ddf95a7cfc654b940bdacb7edde97"},{"url":"https://git.kernel.org/stable/c/0025276175fbbe0dcbf3f84d090b0adee769e9d9"},{"url":"https://git.kernel.org/stable/c/347b59e9f96719d89b6ef555d02a18ada1a5846f"},{"url":"https://git.kernel.org/stable/c/0443e4416aa1ee97748d1ed904eaf3352c60045e"},{"url":"https://git.kernel.org/stable/c/c5371e0b91b24159a3ebaa61e70b0980bcf03c0a"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T04:53:33.891Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"5.10.261"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"5.15.212"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"6.1.178"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"6.12.96"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"6.18.39"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"7.1.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.7","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}