{"id":"CVE-2025-38493","url":"https://www.cyber-defence.io/tools/cve/CVE-2025-38493","generatedAt":"2026-10-28T00:20:07.140Z","title":"In the Linux kernel, the following vulnerability has been resolved: tracing/osnoise: Fix crash in timerlat_dump_stack() We have observed kernel panics when using timerlat with stack saving, with the following dmesg output: memcpy: detected buffer…","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntracing/osnoise: Fix crash in timerlat_dump_stack()\n\nWe have observed kernel panics when using timerlat with stack saving,\nwith the following dmesg output:\n\nmemcpy: detected buffer overflow: 88 byte write of buffer size 0\nWARNING: CPU: 2 PID: 8153 at lib/string_helpers.c:1032 __fortify_report+0x55/0xa0\nCPU: 2 UID: 0 PID: 8153 Comm: timerlatu/2 Kdump: loaded Not tainted 6.15.3-200.fc42.x86_64 #1 PREEMPT(lazy)\nCall Trace:\n <TASK>\n ? trace_buffer_lock_reserve+0x2a/0x60\n __fortify_panic+0xd/0xf\n __timerlat_dump_stack.cold+0xd/0xd\n timerlat_dump_stack.part.0+0x47/0x80\n timerlat_fd_read+0x36d/0x390\n vfs_read+0xe2/0x390\n ? syscall_exit_to_user_mode+0x1d5/0x210\n ksys_read+0x73/0xe0\n do_syscall_64+0x7b/0x160\n ? exc_page_fault+0x7e/0x1a0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\n__timerlat_dump_stack() constructs the ftrace stack entry like this:\n\nstruct stack_entry *entry;\n...\nmemcpy(&entry->caller, fstack->calls, size);\nentry->size = fstack->nr_entries;\n\nSince commit e7186af7fb26 (\"tracing: Add back FORTIFY_SOURCE logic to\nkernel_stack event structure\"), struct stack_entry marks its caller\nfield with __counted_by(size). At the time of the memcpy, entry->size\ncontains garbage from the ringbuffer, which under some circumstances is\nzero, triggering a kernel panic by buffer overflow.\n\nPopulate the size field before the memcpy so that the out-of-bounds\ncheck knows the correct size. This is analogous to\n__ftrace_trace_stack().","published":"2025-07-28T12:15:31.000Z","lastModified":"2026-06-17T09:16:59.000Z","status":"Analyzed","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":5.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-674"],"affected":["linux/linux kernel"],"epss":{"score":0.0017,"percentile":0.06355,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.17%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/7bb9ea515cda027c9e717e27fefcf34f092e7c41","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/823d798900481875ba6c68217af028c5ffd2976b","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/85a3bce695b361d85fc528e6fbb33e4c8089c806","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/fbf90f5aa7ac7cddc69148a71d58f12c8709ce2b","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-38493","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}