CVE-2026-80560 (GCVE-0-2026-80560)

Vulnerability from cvelistv5 – Published: 2026-08-26 14:37 – Updated: 2026-08-26 14:37
VLAI
Title
openrisc: signal: do not restore privileged SR bits on sigreturn
Summary
In the Linux kernel, the following vulnerability has been resolved: openrisc: signal: do not restore privileged SR bits on sigreturn restore_sigcontext() copies the whole supervision register (SR) from the signal frame and only clears SPR_SR_SM before the value is reloaded into the hardware SR (through ESR and l.rfe) on the return to user space. All other SR bits are left under user control. An unprivileged task can thus return from a signal handler through a crafted sigframe that clears SPR_SR_DME. With the data MMU disabled the CPU performs no translation or protection on data accesses, so the task gains read and write access to arbitrary physical memory, a local privilege escalation. SPR_SR_IME, SPR_SR_SUMRA, SPR_SR_LEE, SPR_SR_EPH and the cache-enable bits are exposed the same way. The ptrace GPR regset already refuses any change to SR for exactly this reason. Restore only the arithmetic flag bits (F, CY, OV) from the signal frame and take every privileged control bit from the SR the kernel saved on signal entry. Verified with qemu-system-or1k -M or1k-sim: before this change an unprivileged PoC clears SPR_SR_DME in rt_sigreturn and writes a marker to physical address 0x03000000 (beyond the kernel's mem=32M); afterwards the same PoC receives SIGSEGV and physical memory is unchanged.
Severity
No CVSS data available.
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: ac689eb7f9d4e270d1365853b82eece669387e2c , < bc2e24ba6e167ccf374a197457aa5640a802f429 (git)
Affected: ac689eb7f9d4e270d1365853b82eece669387e2c , < cf1b5514ddf9df098ce7e3741fc9679fd85a4ec6 (git)
Affected: ac689eb7f9d4e270d1365853b82eece669387e2c , < cd8b43a71755c516f5c1f265a103438ae9ab15be (git)
Affected: ac689eb7f9d4e270d1365853b82eece669387e2c , < b4d73c3848bae9084fa8b9b2aa76d99a7d8eb17d (git)
Affected: ac689eb7f9d4e270d1365853b82eece669387e2c , < 89a91b30685c0493b0fa2b47d0ab41061a63069d (git)
Affected: ac689eb7f9d4e270d1365853b82eece669387e2c , < a88d688be8d7f03cbf927f2ab454ea9fa58d2979 (git)
Affected: ac689eb7f9d4e270d1365853b82eece669387e2c , < 212fc482ddd7f9ccdd74a05eab1cac849350dcd6 (git)
Affected: ac689eb7f9d4e270d1365853b82eece669387e2c , < 32ef1b30ad736519f7a207bcc2986f3d4129d972 (git)
guessed Create a notification for this product.
Linux Linux Affected: 3.1
Unaffected: 0 , < 3.1 (semver)
Unaffected: 5.10.266 , ≤ 5.10.* (semver)
Unaffected: 5.15.217 , ≤ 5.15.* (semver)
Unaffected: 6.1.184 , ≤ 6.1.* (semver)
Unaffected: 6.6.153 , ≤ 6.6.* (semver)
Unaffected: 6.12.105 , ≤ 6.12.* (semver)
Unaffected: 6.18.46 , ≤ 6.18.* (semver)
Unaffected: 7.1.10 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/openrisc/include/asm/processor.h",
            "arch/openrisc/kernel/signal.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "bc2e24ba6e167ccf374a197457aa5640a802f429",
              "status": "affected",
              "version": "ac689eb7f9d4e270d1365853b82eece669387e2c",
              "versionType": "git"
            },
            {
              "lessThan": "cf1b5514ddf9df098ce7e3741fc9679fd85a4ec6",
              "status": "affected",
              "version": "ac689eb7f9d4e270d1365853b82eece669387e2c",
              "versionType": "git"
            },
            {
              "lessThan": "cd8b43a71755c516f5c1f265a103438ae9ab15be",
              "status": "affected",
              "version": "ac689eb7f9d4e270d1365853b82eece669387e2c",
              "versionType": "git"
            },
            {
              "lessThan": "b4d73c3848bae9084fa8b9b2aa76d99a7d8eb17d",
              "status": "affected",
              "version": "ac689eb7f9d4e270d1365853b82eece669387e2c",
              "versionType": "git"
            },
            {
              "lessThan": "89a91b30685c0493b0fa2b47d0ab41061a63069d",
              "status": "affected",
              "version": "ac689eb7f9d4e270d1365853b82eece669387e2c",
              "versionType": "git"
            },
            {
              "lessThan": "a88d688be8d7f03cbf927f2ab454ea9fa58d2979",
              "status": "affected",
              "version": "ac689eb7f9d4e270d1365853b82eece669387e2c",
              "versionType": "git"
            },
            {
              "lessThan": "212fc482ddd7f9ccdd74a05eab1cac849350dcd6",
              "status": "affected",
              "version": "ac689eb7f9d4e270d1365853b82eece669387e2c",
              "versionType": "git"
            },
            {
              "lessThan": "32ef1b30ad736519f7a207bcc2986f3d4129d972",
              "status": "affected",
              "version": "ac689eb7f9d4e270d1365853b82eece669387e2c",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/openrisc/include/asm/processor.h",
            "arch/openrisc/kernel/signal.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.1"
            },
            {
              "lessThan": "3.1",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.266",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.217",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.184",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.153",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.105",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.46",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.266",
                  "versionStartIncluding": "3.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.217",
                  "versionStartIncluding": "3.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.184",
                  "versionStartIncluding": "3.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.153",
                  "versionStartIncluding": "3.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.105",
                  "versionStartIncluding": "3.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.46",
                  "versionStartIncluding": "3.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.10",
                  "versionStartIncluding": "3.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "3.1",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nopenrisc: signal: do not restore privileged SR bits on sigreturn\n\nrestore_sigcontext() copies the whole supervision register (SR) from the\nsignal frame and only clears SPR_SR_SM before the value is reloaded into\nthe hardware SR (through ESR and l.rfe) on the return to user space.  All\nother SR bits are left under user control.\n\nAn unprivileged task can thus return from a signal handler through a\ncrafted sigframe that clears SPR_SR_DME.  With the data MMU disabled the\nCPU performs no translation or protection on data accesses, so the task\ngains read and write access to arbitrary physical memory, a local\nprivilege escalation.  SPR_SR_IME, SPR_SR_SUMRA, SPR_SR_LEE, SPR_SR_EPH\nand the cache-enable bits are exposed the same way.  The ptrace GPR regset\nalready refuses any change to SR for exactly this reason.\n\nRestore only the arithmetic flag bits (F, CY, OV) from the signal frame\nand take every privileged control bit from the SR the kernel saved on\nsignal entry.\n\nVerified with qemu-system-or1k -M or1k-sim: before this change an\nunprivileged PoC clears SPR_SR_DME in rt_sigreturn and writes a marker to\nphysical address 0x03000000 (beyond the kernel\u0027s mem=32M); afterwards the\nsame PoC receives SIGSEGV and physical memory is unchanged."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-26T14:37:25.971Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/bc2e24ba6e167ccf374a197457aa5640a802f429"
        },
        {
          "url": "https://git.kernel.org/stable/c/cf1b5514ddf9df098ce7e3741fc9679fd85a4ec6"
        },
        {
          "url": "https://git.kernel.org/stable/c/cd8b43a71755c516f5c1f265a103438ae9ab15be"
        },
        {
          "url": "https://git.kernel.org/stable/c/b4d73c3848bae9084fa8b9b2aa76d99a7d8eb17d"
        },
        {
          "url": "https://git.kernel.org/stable/c/89a91b30685c0493b0fa2b47d0ab41061a63069d"
        },
        {
          "url": "https://git.kernel.org/stable/c/a88d688be8d7f03cbf927f2ab454ea9fa58d2979"
        },
        {
          "url": "https://git.kernel.org/stable/c/212fc482ddd7f9ccdd74a05eab1cac849350dcd6"
        },
        {
          "url": "https://git.kernel.org/stable/c/32ef1b30ad736519f7a207bcc2986f3d4129d972"
        }
      ],
      "title": "openrisc: signal: do not restore privileged SR bits on sigreturn",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-80560",
    "datePublished": "2026-08-26T14:37:25.971Z",
    "dateReserved": "2026-08-26T14:34:25.767Z",
    "dateUpdated": "2026-08-26T14:37:25.971Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-80560\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-08-26T15:17:10.850\",\"lastModified\":\"2026-08-26T15:17:10.850\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nopenrisc: signal: do not restore privileged SR bits on sigreturn\\n\\nrestore_sigcontext() copies the whole supervision register (SR) from the\\nsignal frame and only clears SPR_SR_SM before the value is reloaded into\\nthe hardware SR (through ESR and l.rfe) on the return to user space.  All\\nother SR bits are left under user control.\\n\\nAn unprivileged task can thus return from a signal handler through a\\ncrafted sigframe that clears SPR_SR_DME.  With the data MMU disabled the\\nCPU performs no translation or protection on data accesses, so the task\\ngains read and write access to arbitrary physical memory, a local\\nprivilege escalation.  SPR_SR_IME, SPR_SR_SUMRA, SPR_SR_LEE, SPR_SR_EPH\\nand the cache-enable bits are exposed the same way.  The ptrace GPR regset\\nalready refuses any change to SR for exactly this reason.\\n\\nRestore only the arithmetic flag bits (F, CY, OV) from the signal frame\\nand take every privileged control bit from the SR the kernel saved on\\nsignal entry.\\n\\nVerified with qemu-system-or1k -M or1k-sim: before this change an\\nunprivileged PoC clears SPR_SR_DME in rt_sigreturn and writes a marker to\\nphysical address 0x03000000 (beyond the kernel\u0027s mem=32M); afterwards the\\nsame PoC receives SIGSEGV and physical memory is unchanged.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"arch/openrisc/include/asm/processor.h\",\"arch/openrisc/kernel/signal.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"ac689eb7f9d4e270d1365853b82eece669387e2c\",\"lessThan\":\"bc2e24ba6e167ccf374a197457aa5640a802f429\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"ac689eb7f9d4e270d1365853b82eece669387e2c\",\"lessThan\":\"cf1b5514ddf9df098ce7e3741fc9679fd85a4ec6\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"ac689eb7f9d4e270d1365853b82eece669387e2c\",\"lessThan\":\"cd8b43a71755c516f5c1f265a103438ae9ab15be\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"ac689eb7f9d4e270d1365853b82eece669387e2c\",\"lessThan\":\"b4d73c3848bae9084fa8b9b2aa76d99a7d8eb17d\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"ac689eb7f9d4e270d1365853b82eece669387e2c\",\"lessThan\":\"89a91b30685c0493b0fa2b47d0ab41061a63069d\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"ac689eb7f9d4e270d1365853b82eece669387e2c\",\"lessThan\":\"a88d688be8d7f03cbf927f2ab454ea9fa58d2979\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"ac689eb7f9d4e270d1365853b82eece669387e2c\",\"lessThan\":\"212fc482ddd7f9ccdd74a05eab1cac849350dcd6\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"ac689eb7f9d4e270d1365853b82eece669387e2c\",\"lessThan\":\"32ef1b30ad736519f7a207bcc2986f3d4129d972\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"arch/openrisc/include/asm/processor.h\",\"arch/openrisc/kernel/signal.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"3.1\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"3.1\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.10.266\",\"lessThanOrEqual\":\"5.10.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.217\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.184\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.153\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.105\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.46\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.10\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/212fc482ddd7f9ccdd74a05eab1cac849350dcd6\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/32ef1b30ad736519f7a207bcc2986f3d4129d972\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/89a91b30685c0493b0fa2b47d0ab41061a63069d\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/a88d688be8d7f03cbf927f2ab454ea9fa58d2979\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/b4d73c3848bae9084fa8b9b2aa76d99a7d8eb17d\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/bc2e24ba6e167ccf374a197457aa5640a802f429\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/cd8b43a71755c516f5c1f265a103438ae9ab15be\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/cf1b5514ddf9df098ce7e3741fc9679fd85a4ec6\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Loading…

Detection rules are retrieved from Rulezet.

Loading…

Loading…

Loading…