{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-93167",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2026-93167"
  ],
  "published": "2026-09-17T16:10:40Z",
  "summary": "csky: Fix a4/a5 restoration in syscall trace path",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncsky: Fix a4/a5 restoration in syscall trace path\n\nThe syscall trace path reloads syscall arguments from pt_regs before\ncalling the syscall handler. On C-SKY ABIv2, the 5th and 6th syscall\narguments are prepared as stack arguments before invoking syscallid.\n\nThe current code adjusts sp before loading LSAVE_A4 and LSAVE_A5. Since\nthose offsets are relative to the original pt_regs base, loading them\nafter changing sp fetches the wrong slots. As a result, traced syscalls\nthat use the 5th or 6th argument may receive corrupted arguments.\n\nThis is visible with mmap2(), which takes six arguments. A small\nPTRACE_SYSCALL reproducer opens a file and maps one page with:\n\n  mmap(NULL, 4096, PROT_READ | PROT_EXEC, MAP_PRIVATE, fd, 0)\n\nBefore the fix, the traced child fails the mmap and exits with 12.\nAfter the fix, the mapping succeeds and the child exits with 0.\n\nFix the trace path by loading a4/a5 from pt_regs before changing sp.\n\nTested on: ck860f, linux-4.19.15, C-SKY abiv2",
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.188",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-93167"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/e9ae8e86eed68bea5d2670eadf61938a43bd2263"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/64e3ec7a71d3b715e2567f19f64207f04999bb0c"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/863fa63fd1491f201ac819f805a8db98d2a32c3d"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/e71a3dc5b8d2ea4d9cfbdb135d6b7777de84212e"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/31c81b376e5f058c7f2c94f69719cf7caec2fc3f"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/a776afa89424570bfa637ebf812ca281a5732904"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/343aa5275484d627c921a42e8e115cae366be5de"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/abb81e5ce7d995baa41556b8125fa59e28ba3be8"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-09-17T16:10:40Z"
  }
}