{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2025-38261",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2025-38261",
    "idYear": 2025,
    "status": "PUBLISHED",
    "publishedAt": "2025-07-09T10:42:36.810Z",
    "updatedAt": "2026-10-21T12:36:53.526Z",
    "importedAt": "2026-10-24T01:57:34.152Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "riscv: save the SR_SUM status over switches",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nriscv: save the SR_SUM status over switches\n\nWhen threads/tasks are switched we need to ensure the old execution's\nSR_SUM state is saved and the new thread has the old SR_SUM state\nrestored.\n\nThe issue was seen under heavy load especially with the syz-stress tool\nrunning, with crashes as follows in schedule_tail:\n\nUnable to handle kernel access to user memory without uaccess routines\nat virtual address 000000002749f0d0\nOops [#1]\nModules linked in:\nCPU: 1 PID: 4875 Comm: syz-executor.0 Not tainted\n5.12.0-rc2-syzkaller-00467-g0d7588ab9ef9 #0\nHardware name: riscv-virtio,qemu (DT)\nepc : schedule_tail+0x72/0xb2 kernel/sched/core.c:4264\n ra : task_pid_vnr include/linux/sched.h:1421 [inline]\n ra : schedule_tail+0x70/0xb2 kernel/sched/core.c:4264\nepc : ffffffe00008c8b0 ra : ffffffe00008c8ae sp : ffffffe025d17ec0\n gp : ffffffe005d25378 tp : ffffffe00f0d0000 t0 : 0000000000000000\n t1 : 0000000000000001 t2 : 00000000000f4240 s0 : ffffffe025d17ee0\n s1 : 000000002749f0d0 a0 : 000000000000002a a1 : 0000000000000003\n a2 : 1ffffffc0cfac500 a3 : ffffffe0000c80cc a4 : 5ae9db91c19bbe00\n a5 : 0000000000000000 a6 : 0000000000f00000 a7 : ffffffe000082eba\n s2 : 0000000000040000 s3 : ffffffe00eef96c0 s4 : ffffffe022c77fe0\n s5 : 0000000000004000 s6 : ffffffe067d74e00 s7 : ffffffe067d74850\n s8 : ffffffe067d73e18 s9 : ffffffe067d74e00 s10: ffffffe00eef96e8\n s11: 000000ae6cdf8368 t3 : 5ae9db91c19bbe00 t4 : ffffffc4043cafb2\n t5 : ffffffc4043cafba t6 : 0000000000040000\nstatus: 0000000000000120 badaddr: 000000002749f0d0 cause:\n000000000000000f\nCall Trace:\n[<ffffffe00008c8b0>] schedule_tail+0x72/0xb2 kernel/sched/core.c:4264\n[<ffffffe000005570>] ret_from_exception+0x0/0x14\nDumping ftrace buffer:\n   (ftrace buffer empty)\n---[ end trace b5f8f9231dc87dda ]---\n\nThe issue comes from the put_user() in schedule_tail\n(kernel/sched/core.c) doing the following:\n\nasmlinkage __visible void schedule_tail(struct task_struct *prev)\n{\n...\n        if (current->set_child_tid)\n                put_user(task_pid_vnr(current), current->set_child_tid);\n...\n}\n\nthe put_user() macro causes the code sequence to come out as follows:\n\n1:\t__enable_user_access()\n2:\treg = task_pid_vnr(current);\n3:\t*current->set_child_tid = reg;\n4:\t__disable_user_access()\n\nThe problem is that we may have a sleeping function as argument which\ncould clear SR_SUM causing the panic above. This was fixed by\nevaluating the argument of the put_user() macro outside the user-enabled\nsection in commit 285a76bb2cf5 (\"riscv: evaluate put_user() arg before\nenabling user access\")\"\n\nIn order for riscv to take advantage of unsafe_get/put_XXX() macros and\nto avoid the same issue we had with put_user() and sleeping functions we\nmust ensure code flow can go through switch_to() from within a region of\ncode with SR_SUM enabled and come back with SR_SUM still enabled. This\npatch addresses the problem allowing future work to enable full use of\nunsafe_get/put_XXX() macros without needing to take a CSR bit flip cost\non every access. Make switch_to() save and restore SR_SUM.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "76d2a0493a17d4c8ecc781366850c3c4f8e1a446",
              "status": "affected",
              "versionType": "git",
              "lessThan": "1b63cdc0d63ae33522b4714642fbefa298acc274"
            },
            {
              "version": "76d2a0493a17d4c8ecc781366850c3c4f8e1a446",
              "status": "affected",
              "versionType": "git",
              "lessThan": "9e7005c3638134df5b7df467c1d884a2482c77cb"
            },
            {
              "version": "76d2a0493a17d4c8ecc781366850c3c4f8e1a446",
              "status": "affected",
              "versionType": "git",
              "lessThan": "69ea599a8dab93a620c92c255be4239a06290a77"
            },
            {
              "version": "76d2a0493a17d4c8ecc781366850c3c4f8e1a446",
              "status": "affected",
              "versionType": "git",
              "lessThan": "788aa64c01f1262310b4c1fb827a36df170d86ea"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "4.15",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "4.15"
            },
            {
              "version": "6.6.160",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "version": "6.12.114",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.15.5",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.15.*"
            },
            {
              "version": "6.16",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}