{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2025-38493",
  "modified": "2026-10-07T14:35:31Z",
  "upstream": [
    "CVE-2025-38493"
  ],
  "published": "2025-07-28T11:22:31Z",
  "summary": "tracing/osnoise: Fix crash in timerlat_dump_stack()",
  "details": "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().",
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.12.34-1+rpt1~bookworm"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.12.34+rpt-rpi-v8-rt",
            "binary_version": "1:6.12.34-1+rpt1~bookworm"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.12.34-1+rpt1~bookworm": {
            "linux_commit": "8f77e03530f65209a377d25023e912b288e039cd",
            "upstream_version": "6.12.34",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.12.40"
          }
        }
      }
    },
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:13",
        "name": "linux"
      },
      "versions": [
        "1:6.12.25-1+rpt1+trixie",
        "1:6.12.34-1+rpt1"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.12.25+rpt-rpi-v8-rt",
            "binary_version": "1:6.12.25-1+rpt1+trixie"
          },
          {
            "binary_name": "linux-image-6.12.34+rpt-rpi-v8-rt",
            "binary_version": "1:6.12.34-1+rpt1"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.12.25-1+rpt1+trixie": {
            "linux_commit": "3dd2c2c507c271d411fab2e82a2b3b7e0b6d3f16",
            "upstream_version": "6.12.25",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.12.40"
          },
          "1:6.12.34-1+rpt1": {
            "linux_commit": "8f77e03530f65209a377d25023e912b288e039cd",
            "upstream_version": "6.12.34",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.12.40"
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2025-38493"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/823d798900481875ba6c68217af028c5ffd2976b"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/7bb9ea515cda027c9e717e27fefcf34f092e7c41"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/fbf90f5aa7ac7cddc69148a71d58f12c8709ce2b"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/85a3bce695b361d85fc528e6fbb33e4c8089c806"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-05-12T04:54:46Z"
  }
}