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OESA-2026-2751 (CVE-2026-46253)

Vulnerability from osv_openeuler – Published: 2026-06-24 11:11 – Updated: 2026-08-06 11:11 – Source website
VLAI
Summary
kernel security update
Details

The Linux Kernel, the operating system core itself.

Security Fix(es):

In the Linux kernel, the following vulnerability has been resolved: pstore/ram: fix buffer overflow in persistent_ram_save_old() persistent_ram_save_old() can be called multiple times for the same persistent_ram_zone (e.g., via ramoops_pstore_read -> ramoops_get_next_prz for PSTORE_TYPE_DMESG records). Currently, the function only allocates prz->old_log when it is NULL, but it unconditionally updates prz->old_log_size to the current buffer size and then performs memcpy_fromio() using this new size. If the buffer size has grown since the first allocation (which can happen across different kernel boot cycles), this leads to: 1. A heap buffer overflow (OOB write) in the memcpy_fromio() calls 2. A subsequent OOB read when ramoops_pstore_read() accesses the buffer using the incorrect (larger) old_log_size The KASAN splat would look similar to: BUG: KASAN: slab-out-of-bounds in ramoops_pstore_read+0x... Read of size N at addr ... by task ... The conditions are likely extremely hard to hit: 0. Crash with a ramoops write of less-than-record-max-size bytes. 1. Reboot: ramoops registers, pstore_get_records(0) reads old crash, allocates old_log with size X 2. Crash handler registered, timer started (if pstore_update_ms >= 0) 3. Oops happens (non-fatal, system continues) 4. pstore_dump() writes oops via ramoops_pstore_write() size Y (>X) 5. pstore_new_entry = 1, pstore_timer_kick() called 6. System continues running (not a panic oops) 7. Timer fires after pstore_update_ms milliseconds 8. pstore_timefunc() → schedule_work() → pstore_dowork() → pstore_get_records(1) 9. ramoops_get_next_prz() → persistent_ram_save_old() 10. buffer_size() returns Y, but old_log is X bytes 11. Y > X: memcpy_fromio() overflows heap Requirements: - a prior crash record exists that did not fill the record size (almost impossible since the crash handler writes as much as it can possibly fit into the record, capped by max record size and the kmsg buffer almost always exceeds the max record size) - pstore_update_ms >= 0 (disabled by default) - Non-fatal oops (system survives) Free and reallocate the buffer when the new size differs from the previously allocated size. This ensures old_log always has sufficient space for the data being copied. The Linux kernel CVE team has assigned CVE-2026-46253 to this issue.(CVE-2026-46253)

In the Linux kernel, the following vulnerability has been resolved:

net/sched: fix pedit partial COW leading to page cache corruption

tcf_pedit_act() computes the COW range for skb_ensure_writable() once before the key loop using tcfp_off_max_hint, but the hint does not account for the runtime header offset added by typed keys. This can leave part of the write region un-COW'd.

Fix by moving skb_ensure_writable() inside the per-key loop where the actual write offset is known, and add overflow checking on the offset arithmetic. For negative offsets (e.g. Ethernet header edits at ingress), use skb_cow() to COW the headroom instead. Guard offset_valid() against INT_MIN, where negation is undefined.(CVE-2026-46331)

Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "aarch64": [
          "bpftool-6.6.0-145.1.16.154.oe2403sp1.aarch64.rpm",
          "bpftool-debuginfo-6.6.0-145.1.16.154.oe2403sp1.aarch64.rpm",
          "kernel-6.6.0-145.1.16.154.oe2403sp1.aarch64.rpm",
          "kernel-debuginfo-6.6.0-145.1.16.154.oe2403sp1.aarch64.rpm",
          "kernel-debugsource-6.6.0-145.1.16.154.oe2403sp1.aarch64.rpm",
          "kernel-devel-6.6.0-145.1.16.154.oe2403sp1.aarch64.rpm",
          "kernel-headers-6.6.0-145.1.16.154.oe2403sp1.aarch64.rpm",
          "kernel-source-6.6.0-145.1.16.154.oe2403sp1.aarch64.rpm",
          "kernel-tools-6.6.0-145.1.16.154.oe2403sp1.aarch64.rpm",
          "kernel-tools-debuginfo-6.6.0-145.1.16.154.oe2403sp1.aarch64.rpm",
          "kernel-tools-devel-6.6.0-145.1.16.154.oe2403sp1.aarch64.rpm",
          "perf-6.6.0-145.1.16.154.oe2403sp1.aarch64.rpm",
          "perf-debuginfo-6.6.0-145.1.16.154.oe2403sp1.aarch64.rpm",
          "python3-perf-6.6.0-145.1.16.154.oe2403sp1.aarch64.rpm",
          "python3-perf-debuginfo-6.6.0-145.1.16.154.oe2403sp1.aarch64.rpm"
        ],
        "src": [
          "kernel-6.6.0-145.1.16.154.oe2403sp1.src.rpm"
        ],
        "x86_64": [
          "bpftool-6.6.0-145.1.16.154.oe2403sp1.x86_64.rpm",
          "bpftool-debuginfo-6.6.0-145.1.16.154.oe2403sp1.x86_64.rpm",
          "kernel-6.6.0-145.1.16.154.oe2403sp1.x86_64.rpm",
          "kernel-debuginfo-6.6.0-145.1.16.154.oe2403sp1.x86_64.rpm",
          "kernel-debugsource-6.6.0-145.1.16.154.oe2403sp1.x86_64.rpm",
          "kernel-devel-6.6.0-145.1.16.154.oe2403sp1.x86_64.rpm",
          "kernel-headers-6.6.0-145.1.16.154.oe2403sp1.x86_64.rpm",
          "kernel-source-6.6.0-145.1.16.154.oe2403sp1.x86_64.rpm",
          "kernel-tools-6.6.0-145.1.16.154.oe2403sp1.x86_64.rpm",
          "kernel-tools-debuginfo-6.6.0-145.1.16.154.oe2403sp1.x86_64.rpm",
          "kernel-tools-devel-6.6.0-145.1.16.154.oe2403sp1.x86_64.rpm",
          "perf-6.6.0-145.1.16.154.oe2403sp1.x86_64.rpm",
          "perf-debuginfo-6.6.0-145.1.16.154.oe2403sp1.x86_64.rpm",
          "python3-perf-6.6.0-145.1.16.154.oe2403sp1.x86_64.rpm",
          "python3-perf-debuginfo-6.6.0-145.1.16.154.oe2403sp1.x86_64.rpm"
        ]
      },
      "package": {
        "ecosystem": "openEuler:24.03-LTS-SP1",
        "name": "kernel",
        "purl": "pkg:rpm/openEuler/kernel\u0026distro=openEuler-24.03-LTS-SP1"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.6.0-145.1.16.154.oe2403sp1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "severity": "High"
  },
  "details": "The Linux Kernel, the operating system core itself.\r\n\r\nSecurity Fix(es):\n\nIn the Linux kernel, the following vulnerability has been resolved:  pstore/ram: fix buffer overflow in persistent_ram_save_old()  persistent_ram_save_old() can be called multiple times for the same persistent_ram_zone (e.g., via ramoops_pstore_read -\u0026gt; ramoops_get_next_prz for PSTORE_TYPE_DMESG records).  Currently, the function only allocates prz-\u0026gt;old_log when it is NULL, but it unconditionally updates prz-\u0026gt;old_log_size to the current buffer size and then performs memcpy_fromio() using this new size. If the buffer size has grown since the first allocation (which can happen across different kernel boot cycles), this leads to:  1. A heap buffer overflow (OOB write) in the memcpy_fromio() calls 2. A subsequent OOB read when ramoops_pstore_read() accesses the buffer    using the incorrect (larger) old_log_size  The KASAN splat would look similar to:   BUG: KASAN: slab-out-of-bounds in ramoops_pstore_read+0x...   Read of size N at addr ... by task ...  The conditions are likely extremely hard to hit:    0. Crash with a ramoops write of less-than-record-max-size bytes.   1. Reboot: ramoops registers, pstore_get_records(0) reads old crash,      allocates old_log with size X   2. Crash handler registered, timer started (if pstore_update_ms \u0026gt;= 0)   3. Oops happens (non-fatal, system continues)   4. pstore_dump() writes oops via ramoops_pstore_write() size Y (\u0026gt;X)   5. pstore_new_entry = 1, pstore_timer_kick() called   6. System continues running (not a panic oops)   7. Timer fires after pstore_update_ms milliseconds   8. pstore_timefunc() \u2192 schedule_work() \u2192 pstore_dowork() \u2192 pstore_get_records(1)   9. ramoops_get_next_prz() \u2192 persistent_ram_save_old()  10. buffer_size() returns Y, but old_log is X bytes  11. Y \u0026gt; X: memcpy_fromio() overflows heap    Requirements:   - a prior crash record exists that did not fill the record size     (almost impossible since the crash handler writes as much as it     can possibly fit into the record, capped by max record size and     the kmsg buffer almost always exceeds the max record size)   - pstore_update_ms \u0026gt;= 0 (disabled by default)   - Non-fatal oops (system survives)  Free and reallocate the buffer when the new size differs from the previously allocated size. This ensures old_log always has sufficient space for the data being copied.  The Linux kernel CVE team has assigned CVE-2026-46253 to this issue.(CVE-2026-46253)\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: fix pedit partial COW leading to page cache corruption\n\ntcf_pedit_act() computes the COW range for skb_ensure_writable()\nonce before the key loop using tcfp_off_max_hint, but the hint does\nnot account for the runtime header offset added by typed keys. This\ncan leave part of the write region un-COW\u0026apos;d.\n\nFix by moving skb_ensure_writable() inside the per-key loop where\nthe actual write offset is known, and add overflow checking on the\noffset arithmetic. For negative offsets (e.g. Ethernet header edits\nat ingress), use skb_cow() to COW the headroom instead. Guard\noffset_valid() against INT_MIN, where negation is undefined.(CVE-2026-46331)",
  "id": "OESA-2026-2751",
  "modified": "2026-08-06T11:11:40Z",
  "published": "2026-06-24T11:11:40Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-2751"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-46253"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-46331"
    }
  ],
  "schema_version": "1.7.2",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "kernel security update",
  "upstream": [
    "CVE-2026-46253",
    "CVE-2026-46331"
  ]
}



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