{"id":"CVE-2026-64327","title":"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…","summary":"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…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 6.9, < 6.12.96","linux_kernel >= 6.13, < 6.18.39","linux_kernel >= 6.19, < 7.1.4","linux_kernel = 7.2"],"patched":["linux_kernel 7.1.4"],"published":"2026-07-25","updated":"2026-09-04","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-64327","references":[{"url":"https://git.kernel.org/stable/c/82cf1142e5ccf2b6d6d22ef713aaf3e5f2b5716b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/82cfd4739011bdc7e87b5d585703427e89ddfaa5","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/9e04055ab5fc0470a0031ee6934739f9aa8f34a5","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f99f32ea9aa976afcbec20647ed33b50a52002c1","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd"],"epss":0.00159,"epssPercentile":0.05504,"ingestedAt":"2026-09-05T13:39:56.246Z","slug":"CVE-2026-64327","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `linux_kernel >= 6.9, < 6.12.96`\n- `linux_kernel >= 6.13, < 6.18.39`\n- `linux_kernel >= 6.19, < 7.1.4`\n- `linux_kernel = 7.2`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 7.1.4`","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}