CVE-2026-63805 (GCVE-0-2026-63805)
Vulnerability from cvelistv5
Published
2026-07-19 12:02
Modified
2026-08-17 04:51
Severity ?
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: crypto: nx - fix nx_crypto_ctx_exit argument nx_crypto_ctx_shash_exit calls nx_crypto_ctx_exit with crypto_shash_ctx(...) but crypto_shash_ctx gives a nx_crypto_ctx *, not a crypto_tfm *. Fix the type in nx_crypto_ctx_exit and drop the bogus crypto_tfm_ctx call. This fixes the following oops: BUG: Unable to handle kernel data access at 0xc0403effffffffc8 Faulting instruction address: 0xc000000000396cb4 Oops: Kernel access of bad area, sig: 11 [#15] Call Trace: nx_crypto_ctx_shash_exit+0x24/0x60 crypto_shash_exit_tfm+0x28/0x40 crypto_destroy_tfm+0x98/0x140 crypto_exit_ahash_using_shash+0x20/0x40 crypto_destroy_tfm+0x98/0x140 hash_release+0x1c/0x30 alg_sock_destruct+0x38/0x60 __sk_destruct+0x48/0x2b0 af_alg_release+0x58/0xb0 __sock_release+0x68/0x150 sock_close+0x20/0x40 __fput+0x110/0x3a0 sys_close+0x48/0xa0 system_call_exception+0x140/0x2d0 system_call_common+0xf4/0x258 .. which came from hardlink(1) opportunistically using AF_ALG. The same problem exists with nx_crypto_ctx_skcipher_exit getting a context it wasn't expecting, but apparently nobody hit that for years.
References
Impacted products
Vendor Product Version
Linux Linux Version: bfd9efddf990d152dc9912fdca520c5e1e19e1e2
Version: bfd9efddf990d152dc9912fdca520c5e1e19e1e2
Version: bfd9efddf990d152dc9912fdca520c5e1e19e1e2
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/crypto/nx/nx.c",
            "drivers/crypto/nx/nx.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "lessThan": "8d8507a457667f23477a15496b91908a5b5b7cf3",
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              "status": "affected",
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              "versionType": "git"
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            {
              "lessThan": "4e67f504ee9ded15e256b64f4fde150e917381d7",
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        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/crypto/nx/nx.c",
            "drivers/crypto/nx/nx.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.5"
            },
            {
              "lessThan": "5.5",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.38",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.3",
              "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": "6.18.38",
                  "versionStartIncluding": "5.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.3",
                  "versionStartIncluding": "5.5",
                  "vulnerable": true
                },
                {
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                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "5.5",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: nx - fix nx_crypto_ctx_exit argument\n\nnx_crypto_ctx_shash_exit calls nx_crypto_ctx_exit with crypto_shash_ctx(...)\nbut crypto_shash_ctx gives a nx_crypto_ctx *, not a crypto_tfm *.\n\nFix the type in nx_crypto_ctx_exit and drop the bogus crypto_tfm_ctx\ncall.\n\nThis fixes the following oops:\n\n  BUG: Unable to handle kernel data access at 0xc0403effffffffc8\n  Faulting instruction address: 0xc000000000396cb4\n  Oops: Kernel access of bad area, sig: 11 [#15]\n  Call Trace:\n   nx_crypto_ctx_shash_exit+0x24/0x60\n   crypto_shash_exit_tfm+0x28/0x40\n   crypto_destroy_tfm+0x98/0x140\n   crypto_exit_ahash_using_shash+0x20/0x40\n   crypto_destroy_tfm+0x98/0x140\n   hash_release+0x1c/0x30\n   alg_sock_destruct+0x38/0x60\n   __sk_destruct+0x48/0x2b0\n   af_alg_release+0x58/0xb0\n   __sock_release+0x68/0x150\n   sock_close+0x20/0x40\n   __fput+0x110/0x3a0\n   sys_close+0x48/0xa0\n   system_call_exception+0x140/0x2d0\n   system_call_common+0xf4/0x258\n\n.. which came from hardlink(1) opportunistically using AF_ALG.\n\nThe same problem exists with nx_crypto_ctx_skcipher_exit getting a context\nit wasn\u0027t expecting, but apparently nobody hit that for years."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - Exploitation requires a local syscall path (socket/AF_ALG bind, then close via sys_close) through the crypto userspace API; the NX driver is not reachable from remote network packet handling.\nAC:L - On affected IBM Power pSeries systems with NX hardware and the nx-crypto driver loaded, an attacker can deterministically trigger the bug by opening an AF_ALG hash socket, binding a SHA algorithm that selects the nx driver, and closing the socket.\nPR:L - No special privileges are required beyond a normal local user account; AF_ALG sockets are available to unprivileged users and remain reachable from user namespaces without init-namespace root.\nUI:N - No victim interaction is needed beyond the attacker running their own program that opens and closes an AF_ALG crypto socket (as demonstrated by hardlink(1) opportunistically using AF_ALG).\nS:U - Impact is confined to kernel memory within the same security authority; this is a local kernel memory-corruption/crash issue, not a VM escape or cross-security-boundary bypass.\nC:H - The type confusion causes reads through a miscomputed context pointer before the fault, and erroneous kfree_sensitive() on attacker-influenced kernel pointers can corrupt heap metadata and enable further information disclosure.\nI:H - The same type confusion leads to kfree_sensitive() on a wrong address and NULL pointer writes through a misaligned nx_crypto_ctx, giving exploitable heap corruption and arbitrary kernel write primitives.\nA:H - The bug reliably causes a kernel oops (SIGSEGV in kernel mode) during crypto context teardown, crashing the calling context and potentially the entire system under panic-on-oops policy."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T04:51:11.095Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/8d8507a457667f23477a15496b91908a5b5b7cf3"
        },
        {
          "url": "https://git.kernel.org/stable/c/833033e6e55acf11304ff7bbbdf18351d139c281"
        },
        {
          "url": "https://git.kernel.org/stable/c/4e67f504ee9ded15e256b64f4fde150e917381d7"
        }
      ],
      "title": "crypto: nx - fix nx_crypto_ctx_exit argument",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-63805",
    "datePublished": "2026-07-19T12:02:09.669Z",
    "dateReserved": "2026-07-19T07:54:57.013Z",
    "dateUpdated": "2026-08-17T04:51:11.095Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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