{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-53163",
  "modified": "2026-10-07T14:35:31Z",
  "upstream": [
    "CVE-2026-53163"
  ],
  "published": "2026-06-25T08:41:40Z",
  "summary": "locking/rtmutex: Skip remove_waiter() when waiter is not enqueued",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nlocking/rtmutex: Skip remove_waiter() when waiter is not enqueued\n\nsyzbot triggered the following splat in remove_waiter() via\nFUTEX_CMP_REQUEUE_PI:\n\n  KASAN: null-ptr-deref in range [0x0000000000000a88-0x0000000000000a8f]\n   class_raw_spinlock_constructor\n   remove_waiter+0x159/0x1200 kernel/locking/rtmutex.c:1561\n   rt_mutex_start_proxy_lock+0x103/0x120\n   futex_requeue+0x10e4/0x20d0\n   __x64_sys_futex+0x34f/0x4d0\n\ntask_blocks_on_rt_mutex() does not arm the waiter upon deadlock detection,\nleaving waiter->task nil, where 3bfdc63936dd (\"rtmutex: Use waiter::task instead\nof current in remove_waiter()\") made this fatal.\n\nFurthermore, rt_mutex_start_proxy_lock() should not be calling into remove_waiter()\nupon a successfully grabbing the rtmutex. 1a1fb985f2e2 (\"futex: Handle early deadlock\nreturn correctly\"), moved the remove_waiter() out of __rt_mutex_start_proxy_lock()\n(where 'ret' was only ever 0 or < 0) into the wrapper. Tighten this check to\naccount for try_to_take_rt_mutex().",
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.12.87-1+rpt1~bookworm",
        "1:6.12.93-1+rpt1"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.12.87+rpt-rpi-2712",
            "binary_version": "1:6.12.87-1+rpt1~bookworm"
          },
          {
            "binary_name": "linux-image-6.12.87+rpt-rpi-v6",
            "binary_version": "1:6.12.87-1+rpt1~bookworm"
          },
          {
            "binary_name": "linux-image-6.12.87+rpt-rpi-v7",
            "binary_version": "1:6.12.87-1+rpt1~bookworm"
          },
          {
            "binary_name": "linux-image-6.12.87+rpt-rpi-v7l",
            "binary_version": "1:6.12.87-1+rpt1~bookworm"
          },
          {
            "binary_name": "linux-image-6.12.87+rpt-rpi-v8",
            "binary_version": "1:6.12.87-1+rpt1~bookworm"
          },
          {
            "binary_name": "linux-image-6.12.87+rpt-rpi-v8-rt",
            "binary_version": "1:6.12.87-1+rpt1~bookworm"
          },
          {
            "binary_name": "linux-image-6.12.93+rpt-rpi-2712",
            "binary_version": "1:6.12.93-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.12.93+rpt-rpi-v6",
            "binary_version": "1:6.12.93-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.12.93+rpt-rpi-v7",
            "binary_version": "1:6.12.93-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.12.93+rpt-rpi-v7l",
            "binary_version": "1:6.12.93-1+rpt1"
          },
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            "binary_name": "linux-image-6.12.93+rpt-rpi-v8",
            "binary_version": "1:6.12.93-1+rpt1"
          },
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            "binary_name": "linux-image-6.12.93+rpt-rpi-v8-rt",
            "binary_version": "1:6.12.93-1+rpt1"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.12.87-1+rpt1~bookworm": {
            "linux_commit": "ae4d75fb36deba0fe1a986d9bfae65755e082dd0",
            "upstream_version": "6.12.87",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.12.95"
          },
          "1:6.12.93-1+rpt1": {
            "linux_commit": "d8ab4e908235da7727f22dd36ad5af224671677d",
            "upstream_version": "6.12.93",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.12.95"
          }
        }
      }
    },
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:13",
        "name": "linux"
      },
      "versions": [
        "1:6.18.29-1+rpt1",
        "1:6.18.33-1+rpt1",
        "1:6.18.34-1+rpt1"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.18.29+rpt-rpi-2712",
            "binary_version": "1:6.18.29-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.29+rpt-rpi-v6",
            "binary_version": "1:6.18.29-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.29+rpt-rpi-v7",
            "binary_version": "1:6.18.29-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.29+rpt-rpi-v8",
            "binary_version": "1:6.18.29-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.29+rpt-rpi-v8-rt",
            "binary_version": "1:6.18.29-1+rpt1"
          },
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            "binary_name": "linux-image-6.18.33+rpt-rpi-2712",
            "binary_version": "1:6.18.33-1+rpt1"
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          {
            "binary_name": "linux-image-6.18.33+rpt-rpi-v6",
            "binary_version": "1:6.18.33-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.33+rpt-rpi-v7",
            "binary_version": "1:6.18.33-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.33+rpt-rpi-v8",
            "binary_version": "1:6.18.33-1+rpt1"
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            "binary_name": "linux-image-6.18.33+rpt-rpi-v8-rt",
            "binary_version": "1:6.18.33-1+rpt1"
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            "binary_version": "1:6.18.34-1+rpt1"
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            "binary_name": "linux-image-6.18.34+rpt-rpi-v6",
            "binary_version": "1:6.18.34-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.34+rpt-rpi-v7",
            "binary_version": "1:6.18.34-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.34+rpt-rpi-v8",
            "binary_version": "1:6.18.34-1+rpt1"
          },
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            "binary_name": "linux-image-6.18.34+rpt-rpi-v8-rt",
            "binary_version": "1:6.18.34-1+rpt1"
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        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.18.29-1+rpt1": {
            "linux_commit": "66318c5b5cd8145a662303af12ed39ac07eb27cc",
            "upstream_version": "6.18.29",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.18.36"
          },
          "1:6.18.33-1+rpt1": {
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            "upstream_version": "6.18.33",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.18.36"
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            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.18.36"
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-53163"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/bfbc047ceb42c0e1fac8f3a155d4548a8bbe76b1"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/4ffacf76a457b7ca8ac05f5df8740b0d8f53574a"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/4afda3a1da02129568a3a2f1898aa13e6763bcba"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/6707d7e0b71748cb3cd95bad81dae5fe1b3c8f48"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/5799f9bd7fee40370b93ab1ddf001cdc7017c14d"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/a388e3dfaf9538a680de5ed43a8ebb5dd45b6e53"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/55363fa0a04524d11efeaadee734d2db1756ed27"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/40a25d59e85b3c8709ac2424d44f65610467871e"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-07-24T14:40:09Z"
  }
}