{"cve":"CVE-2025-39683","nvd":{"published":"2025-09-05T18:15:44.810","modified":"2026-10-19T21:10:00.160","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Limit access to parser->buffer when trace_get_user failed\n\nWhen the length of the string written to set_ftrace_filter exceeds\nFTRACE_BUFF_MAX, the following KASAN alarm will be triggered:\n\nBUG: KASAN: slab-out-of-bounds in strsep+0x18c/0x1b0\nRead of size 1 at addr ffff0000d00bd5ba by task ash/165\n\nCPU: 1 UID: 0 PID: 165 Comm: ash Not tainted 6.16.0-g6bcdbd62bd56-dirty\nHardware name: linux,dummy-virt (DT)\nCall trace:\n show_stack+0x34/0x50 (C)\n dump_stack_lvl+0xa0/0x158\n print_address_description.constprop.0+0x88/0x398\n print_report+0xb0/0x280\n kasan_report+0xa4/0xf0\n __asan_report_load1_noabort+0x20/0x30\n strsep+0x18c/0x1b0\n ftrace_process_regex.isra.0+0x100/0x2d8\n ftrace_regex_release+0x484/0x618\n __fput+0x364/0xa58\n ____fput+0x28/0x40\n task_work_run+0x154/0x278\n do_notify_resume+0x1f0/0x220\n el0_svc+0xec/0xf0\n el0t_64_sync_handler+0xa0/0xe8\n el0t_64_sync+0x1ac/0x1b0\n\nThe reason is that trace_get_user will fail when processing a string\nlonger than FTRACE_BUFF_MAX, but not set the end of parser->buffer to 0.\nThen an OOB access will be triggered in ftrace_regex_release->\nftrace_process_regex->strsep->strpbrk. We can solve this problem by\nlimiting access to parser->buffer when trace_get_user failed.","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:N/A:H","score":7.1},"cwes":["CWE-125"],"references":["https://git.kernel.org/stable/c/3079517a5ba80901fe828a06998da64b9b8749be","https://git.kernel.org/stable/c/418b448e1d7470da9d4d4797f71782595ee69c49","https://git.kernel.org/stable/c/41b838420457802f21918df66764b6fbf829d330","https://git.kernel.org/stable/c/58ff8064cb4c7eddac4da1a59da039ead586950a","https://git.kernel.org/stable/c/6a909ea83f226803ea0e718f6e88613df9234d58"],"products":["debian:debian_linux","linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2025-39683","score":0.00184,"percentile":0.07951,"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."]}