{"cve":"CVE-2025-39855","nvd":{"published":"2025-09-19T16:15:44.437","modified":"2026-10-19T21:10:00.160","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nice: fix NULL access of tx->in_use in ice_ptp_ts_irq\n\nThe E810 device has support for a \"low latency\" firmware interface to\naccess and read the Tx timestamps. This interface does not use the standard\nTx timestamp logic, due to the latency overhead of proxying sideband\ncommand requests over the firmware AdminQ.\n\nThe logic still makes use of the Tx timestamp tracking structure,\nice_ptp_tx, as it uses the same \"ready\" bitmap to track which Tx\ntimestamps complete.\n\nUnfortunately, the ice_ptp_ts_irq() function does not check if the tracker\nis initialized before its first access. This results in NULL dereference or\nuse-after-free bugs similar to the following:\n\n[245977.278756] BUG: kernel NULL pointer dereference, address: 0000000000000000\n[245977.278774] RIP: 0010:_find_first_bit+0x19/0x40\n[245977.278796] Call Trace:\n[245977.278809]  ? ice_misc_intr+0x364/0x380 [ice]\n\nThis can occur if a Tx timestamp interrupt races with the driver reset\nlogic.\n\nFix this by only checking the in_use bitmap (and other fields) if the\ntracker is marked as initialized. The reset flow will clear the init field\nunder lock before it tears the tracker down, thus preventing any\nuse-after-free or NULL access.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-416"],"references":["https://git.kernel.org/stable/c/1467a873b20110263cc9c93de99335d139c11e16","https://git.kernel.org/stable/c/403bf043d9340196e06769065169df7444b91f7a"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2025-39855","score":0.00166,"percentile":0.05757,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}