{"id":"CVE-2026-64427","summary":"HID: logitech-dj: Fix maxfield check in DJ short report validation","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nHID: logitech-dj: Fix maxfield check in DJ short report validation\n\nCommit b6a57912854e (\"HID: logitech-dj: Prevent REPORT_ID_DJ_SHORT\nrelated user initiated OOB write\") added validation for the DJ short\noutput report, but the error path dereferences rep-\u003efield[0] even when\nrep-\u003emaxfield is zero.\n\nCommit 8b9a097eb2fc (\"HID: logitech-dj: fix wrong detection of bad\nDJ_SHORT output report\") made the check conditional on rep being present,\nbut a crafted descriptor can still create report ID 0x20 with only padding\noutput items. hid-core registers the report, ignores the padding field,\nand leaves rep-\u003emaxfield as zero.\n\nIn that case the validation enters the rep-\u003emaxfield \u003c 1 branch and then\ndereferences rep-\u003efield[0]-\u003ereport_count while printing the error message,\ncausing a NULL pointer dereference during probe. This is reproducible with\nuhid by emulating a Logitech receiver with a padding-only DJ short output\nreport:\n\n  BUG: KASAN: null-ptr-deref in logi_dj_probe+0xb1/0x754 [hid_logitech_dj]\n  Read of size 4 at addr 0000000000000028 by task kworker/4:1/129\n  ...\n  Call Trace:\n   logi_dj_probe+0xb1/0x754 [hid_logitech_dj]\n   hid_device_probe+0x329/0x3f0 [hid]\n   really_probe+0x162/0x570\n   __device_attach+0x137/0x2c0\n   bus_probe_device+0x38/0xc0\n   device_add+0xa56/0xce0\n   hid_add_device+0x19c/0x280 [hid]\n   uhid_device_add_worker+0x2c/0xb0 [uhid]\n\nReject the zero-field report before printing the field report_count.","modified":"2026-07-27T04:03:22.055339786Z","published":"2026-07-25T08:51:04.686Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64427.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/590cc4d782487632a52f37c2171bee1eeea29627"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7a89ad762fad53d56b7002d7ffc923a4b7f4006f"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64427.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64427"},{"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":"b6a57912854e7ea36f3b270032661140cc4209cd"},{"fixed":"7a89ad762fad53d56b7002d7ffc923a4b7f4006f"},{"fixed":"590cc4d782487632a52f37c2171bee1eeea29627"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64427.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"7.1.0"},{"fixed":"7.1.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64427.json"}}],"schema_version":"1.7.5"}