{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "descriptions": [
            {
               "lang": "en",
               "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nspi: bcm2835: Fix out-of-bounds access with more than 4 slaves\n\nCommit 571e31fa60b3 (\"spi: bcm2835: Cache CS register value for\n->prepare_message()\") limited the number of slaves to 3 at compile-time.\nThe limitation was necessitated by a statically-sized array prepare_cs[]\nin the driver private data which contains a per-slave register value.\n\nThe commit sought to enforce the limitation at run-time by setting the\ncontroller's num_chipselect to 3:  Slaves with a higher chipselect are\nrejected by spi_add_device().\n\nHowever the commit neglected that num_chipselect only limits the number\nof *native* chipselects.  If GPIO chipselects are specified in the\ndevice tree for more than 3 slaves, num_chipselect is silently raised by\nof_spi_get_gpio_numbers() and the result are out-of-bounds accesses to\nthe statically-sized array prepare_cs[].\n\nAs a bandaid fix which is backportable to stable, raise the number of\nallowed slaves to 24 (which \"ought to be enough for anybody\"), enforce\nthe limitation on slave ->setup and revert num_chipselect to 3 (which is\nthe number of native chipselects supported by the controller).\nAn upcoming for-next commit will allow an arbitrary number of slaves."
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "drivers/spi/spi-bcm2835.c"
               ],
               "versions": [
                  {
                     "version": "571e31fa60b3",
                     "lessThan": "b5502580cf95",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "571e31fa60b3",
                     "lessThan": "82a8ffba54d3",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "571e31fa60b3",
                     "lessThan": "01415ff85a24",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "571e31fa60b3",
                     "lessThan": "13817d466eb8",
                     "status": "affected",
                     "versionType": "git"
                  }
               ]
            },
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "affected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "drivers/spi/spi-bcm2835.c"
               ],
               "versions": [
                  {
                     "version": "5.4",
                     "status": "affected"
                  },
                  {
                     "version": "0",
                     "lessThan": "5.4",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.4.126",
                     "lessThanOrEqual": "5.4.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.10.44",
                     "lessThanOrEqual": "5.10.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.12.11",
                     "lessThanOrEqual": "5.12.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.13",
                     "lessThanOrEqual": "*",
                     "status": "unaffected",
                     "versionType": "original_commit_for_fix"
                  }
               ]
            }
         ],
         "references": [
            {
               "url": "https://git.kernel.org/stable/c/b5502580cf958b094f3b69dfe4eece90eae01fbc"
            },
            {
               "url": "https://git.kernel.org/stable/c/82a8ffba54d31e97582051cb56ba1f988018681e"
            },
            {
               "url": "https://git.kernel.org/stable/c/01415ff85a24308059e06ca3e97fd7bf75648690"
            },
            {
               "url": "https://git.kernel.org/stable/c/13817d466eb8713a1ffd254f537402f091d48444"
            }
         ],
         "title": "spi: bcm2835: Fix out-of-bounds access with more than 4 slaves",
         "x_generator": {
            "engine": "bippy-a5840b7849dd"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2021-47282",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}