{"id":"CVE-2026-64264","summary":"fuse-uring: fix EFAULT clobber in fuse_uring_commit","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nfuse-uring: fix EFAULT clobber in fuse_uring_commit\n\ncopy_from_user() returns the number of bytes not copied as an unsigned\nresidual on failure (1..sizeof(struct fuse_out_header)). fuse_uring_commit\nstores that residual in ssize_t err, sets req-\u003eout.h.error to -EFAULT,\nthen jumps to out: with err still holding the positive residual.\n\n    err = copy_from_user(&req-\u003eout.h, &ent-\u003eheaders-\u003ein_out,\n                         sizeof(req-\u003eout.h));\n    if (err) {\n        req-\u003eout.h.error = -EFAULT;\n        goto out;          /* err is the positive residual */\n    }\n    ...\n    out:\n        fuse_uring_req_end(ent, req, err);\n\nfuse_uring_req_end() then runs\n\n    if (error)\n        req-\u003eout.h.error = error;\n\nwhich overwrites the just-assigned -EFAULT with the positive residual.\nFUSE callers such as fuse_simple_request() test err \u003c 0 to detect\nfailure, so the positive value is interpreted as success and the\ncaller proceeds with an uninitialised or partial req-\u003eout.args.\n\nFix by assigning err = -EFAULT in the failure branch before jumping\nto out, so fuse_uring_req_end() receives a negative errno and sets\nreq-\u003eout.h.error to -EFAULT.","modified":"2026-08-18T03:30:59.062369366Z","published":"2026-07-25T08:49:13.891Z","related":["CGA-vv7p-mcmm-f782","openSUSE-SU-2026:11476-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64264.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0483fffdeeb363f320e6bf5fc0f0306007507306"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3a0a8bc51a13951c5141262bf770eeea3e0b6228"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fe604c08d874648a69187f6380e5c7858627dc04"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64264.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64264"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"c090c8abae4b6b77a1bee116aa6c385456ebef96"},{"fixed":"0483fffdeeb363f320e6bf5fc0f0306007507306"},{"fixed":"fe604c08d874648a69187f6380e5c7858627dc04"},{"fixed":"3a0a8bc51a13951c5141262bf770eeea3e0b6228"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64264.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.14.0"},{"fixed":"6.18.39"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64264.json"}}],"schema_version":"1.9.0"}