{"id":"CVE-2026-64327","state":"PUBLISHED","title":"usb: gadget: f_fs: Initialize epfile->in early to fix endpoint direction checks","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: f_fs: Initialize epfile->in early to fix endpoint direction checks\n\nWhen parsing endpoint descriptors, ffs_data_got_descs() generates the\neps_addrmap which contains the endpoint direction. However, epfile->in\nwas previously only populated in ffs_func_eps_enable() which executes\nupon USB host connection. As a result, early userspace ioctls like\nFUNCTIONFS_DMABUF_ATTACH that run before the host connects would see\nepfile->in as 0, leading to incorrect DMA directions.\n\nBy moving the initialization to ffs_epfiles_create(), epfile->in is\naccurate before userspace opens the endpoint files.","publishedAt":"2026-07-25T08:49:55.426Z","updatedAt":"2026-08-17T04:53:29.409Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"7b07a2a7ca02a20124b552be96c5a56910795488","status":"affected","lessThan":"82cf1142e5ccf2b6d6d22ef713aaf3e5f2b5716b","versionType":"git"},{"version":"7b07a2a7ca02a20124b552be96c5a56910795488","status":"affected","lessThan":"9e04055ab5fc0470a0031ee6934739f9aa8f34a5","versionType":"git"},{"version":"7b07a2a7ca02a20124b552be96c5a56910795488","status":"affected","lessThan":"f99f32ea9aa976afcbec20647ed33b50a52002c1","versionType":"git"},{"version":"7b07a2a7ca02a20124b552be96c5a56910795488","status":"affected","lessThan":"82cfd4739011bdc7e87b5d585703427e89ddfaa5","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/usb/gadget/function/f_fs.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.9","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/gadget/function/f_fs.c"]}],"references":["https://git.kernel.org/stable/c/82cf1142e5ccf2b6d6d22ef713aaf3e5f2b5716b","https://git.kernel.org/stable/c/9e04055ab5fc0470a0031ee6934739f9aa8f34a5","https://git.kernel.org/stable/c/f99f32ea9aa976afcbec20647ed33b50a52002c1","https://git.kernel.org/stable/c/82cfd4739011bdc7e87b5d585703427e89ddfaa5"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64327.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64327","state":"PUBLISHED","datePublished":"2026-07-25T08:49:55.426Z","dateUpdated":"2026-08-17T04:53:29.409Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T15:36:31.780Z"},"containers":{"cna":{"title":"usb: gadget: f_fs: Initialize epfile->in early to fix endpoint direction checks","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: f_fs: Initialize epfile->in early to fix endpoint direction checks\n\nWhen parsing endpoint descriptors, ffs_data_got_descs() generates the\neps_addrmap which contains the endpoint direction. However, epfile->in\nwas previously only populated in ffs_func_eps_enable() which executes\nupon USB host connection. As a result, early userspace ioctls like\nFUNCTIONFS_DMABUF_ATTACH that run before the host connects would see\nepfile->in as 0, leading to incorrect DMA directions.\n\nBy moving the initialization to ffs_epfiles_create(), epfile->in is\naccurate before userspace opens the endpoint files."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"7b07a2a7ca02a20124b552be96c5a56910795488","status":"affected","lessThan":"82cf1142e5ccf2b6d6d22ef713aaf3e5f2b5716b","versionType":"git"},{"version":"7b07a2a7ca02a20124b552be96c5a56910795488","status":"affected","lessThan":"9e04055ab5fc0470a0031ee6934739f9aa8f34a5","versionType":"git"},{"version":"7b07a2a7ca02a20124b552be96c5a56910795488","status":"affected","lessThan":"f99f32ea9aa976afcbec20647ed33b50a52002c1","versionType":"git"},{"version":"7b07a2a7ca02a20124b552be96c5a56910795488","status":"affected","lessThan":"82cfd4739011bdc7e87b5d585703427e89ddfaa5","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/usb/gadget/function/f_fs.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.9","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/gadget/function/f_fs.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/82cf1142e5ccf2b6d6d22ef713aaf3e5f2b5716b"},{"url":"https://git.kernel.org/stable/c/9e04055ab5fc0470a0031ee6934739f9aa8f34a5"},{"url":"https://git.kernel.org/stable/c/f99f32ea9aa976afcbec20647ed33b50a52002c1"},{"url":"https://git.kernel.org/stable/c/82cfd4739011bdc7e87b5d585703427e89ddfaa5"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T04:53:29.409Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"6.12.96"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"6.18.39"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"7.1.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}