cve-2024-49885
Vulnerability from cvelistv5
Published
2024-10-21 18:01
Modified
2025-05-04 09:40
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: mm, slub: avoid zeroing kmalloc redzone Since commit 946fa0dbf2d8 ("mm/slub: extend redzone check to extra allocated kmalloc space than requested"), setting orig_size treats the wasted space (object_size - orig_size) as a redzone. However with init_on_free=1 we clear the full object->size, including the redzone. Additionally we clear the object metadata, including the stored orig_size, making it zero, which makes check_object() treat the whole object as a redzone. These issues lead to the following BUG report with "slub_debug=FUZ init_on_free=1": [ 0.000000] ============================================================================= [ 0.000000] BUG kmalloc-8 (Not tainted): kmalloc Redzone overwritten [ 0.000000] ----------------------------------------------------------------------------- [ 0.000000] [ 0.000000] 0xffff000010032858-0xffff00001003285f @offset=2136. First byte 0x0 instead of 0xcc [ 0.000000] FIX kmalloc-8: Restoring kmalloc Redzone 0xffff000010032858-0xffff00001003285f=0xcc [ 0.000000] Slab 0xfffffdffc0400c80 objects=36 used=23 fp=0xffff000010032a18 flags=0x3fffe0000000200(workingset|node=0|zone=0|lastcpupid=0x1ffff) [ 0.000000] Object 0xffff000010032858 @offset=2136 fp=0xffff0000100328c8 [ 0.000000] [ 0.000000] Redzone ffff000010032850: cc cc cc cc cc cc cc cc ........ [ 0.000000] Object ffff000010032858: cc cc cc cc cc cc cc cc ........ [ 0.000000] Redzone ffff000010032860: cc cc cc cc cc cc cc cc ........ [ 0.000000] Padding ffff0000100328b4: 00 00 00 00 00 00 00 00 00 00 00 00 ............ [ 0.000000] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.11.0-rc3-next-20240814-00004-g61844c55c3f4 #144 [ 0.000000] Hardware name: NXP i.MX95 19X19 board (DT) [ 0.000000] Call trace: [ 0.000000] dump_backtrace+0x90/0xe8 [ 0.000000] show_stack+0x18/0x24 [ 0.000000] dump_stack_lvl+0x74/0x8c [ 0.000000] dump_stack+0x18/0x24 [ 0.000000] print_trailer+0x150/0x218 [ 0.000000] check_object+0xe4/0x454 [ 0.000000] free_to_partial_list+0x2f8/0x5ec To address the issue, use orig_size to clear the used area. And restore the value of orig_size after clear the remaining area. When CONFIG_SLUB_DEBUG not defined, (get_orig_size()' directly returns s->object_size. So when using memset to init the area, the size can simply be orig_size, as orig_size returns object_size when CONFIG_SLUB_DEBUG not enabled. And orig_size can never be bigger than object_size.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/59090e479ac78ae18facd4c58eb332562a23020ePatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/7a2e823a19746d54052c625faecf0d2d6c52ee0aPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/83f0440b2f92227fcce9898118ca7fe7e0d64b1fPatch
Impacted products
Vendor Product Version
Linux Linux Version: 946fa0dbf2d8923a587f7348adf16563d59f1b3d
Version: 946fa0dbf2d8923a587f7348adf16563d59f1b3d
Version: 946fa0dbf2d8923a587f7348adf16563d59f1b3d
 Create a notification for this product.
   Linux Linux Version: 6.2
 Create a notification for this product.
Show details on NVD website

To clipboard 

{
   containers: {
      adp: [
         {
            metrics: [
               {
                  other: {
                     content: {
                        id: "CVE-2024-49885",
                        options: [
                           {
                              Exploitation: "none",
                           },
                           {
                              Automatable: "no",
                           },
                           {
                              "Technical Impact": "partial",
                           },
                        ],
                        role: "CISA Coordinator",
                        timestamp: "2024-10-22T13:45:07.682094Z",
                        version: "2.0.3",
                     },
                     type: "ssvc",
                  },
               },
            ],
            providerMetadata: {
               dateUpdated: "2024-10-22T13:48:49.969Z",
               orgId: "134c704f-9b21-4f2e-91b3-4a467353bcc0",
               shortName: "CISA-ADP",
            },
            title: "CISA ADP Vulnrichment",
         },
      ],
      cna: {
         affected: [
            {
               defaultStatus: "unaffected",
               product: "Linux",
               programFiles: [
                  "mm/slub.c",
               ],
               repo: "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               vendor: "Linux",
               versions: [
                  {
                     lessThan: "7a2e823a19746d54052c625faecf0d2d6c52ee0a",
                     status: "affected",
                     version: "946fa0dbf2d8923a587f7348adf16563d59f1b3d",
                     versionType: "git",
                  },
                  {
                     lessThan: "83f0440b2f92227fcce9898118ca7fe7e0d64b1f",
                     status: "affected",
                     version: "946fa0dbf2d8923a587f7348adf16563d59f1b3d",
                     versionType: "git",
                  },
                  {
                     lessThan: "59090e479ac78ae18facd4c58eb332562a23020e",
                     status: "affected",
                     version: "946fa0dbf2d8923a587f7348adf16563d59f1b3d",
                     versionType: "git",
                  },
               ],
            },
            {
               defaultStatus: "affected",
               product: "Linux",
               programFiles: [
                  "mm/slub.c",
               ],
               repo: "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               vendor: "Linux",
               versions: [
                  {
                     status: "affected",
                     version: "6.2",
                  },
                  {
                     lessThan: "6.2",
                     status: "unaffected",
                     version: "0",
                     versionType: "semver",
                  },
                  {
                     lessThanOrEqual: "6.10.*",
                     status: "unaffected",
                     version: "6.10.14",
                     versionType: "semver",
                  },
                  {
                     lessThanOrEqual: "6.11.*",
                     status: "unaffected",
                     version: "6.11.3",
                     versionType: "semver",
                  },
                  {
                     lessThanOrEqual: "*",
                     status: "unaffected",
                     version: "6.12",
                     versionType: "original_commit_for_fix",
                  },
               ],
            },
         ],
         cpeApplicability: [
            {
               nodes: [
                  {
                     cpeMatch: [
                        {
                           criteria: "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                           versionEndExcluding: "6.10.14",
                           versionStartIncluding: "6.2",
                           vulnerable: true,
                        },
                        {
                           criteria: "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                           versionEndExcluding: "6.11.3",
                           versionStartIncluding: "6.2",
                           vulnerable: true,
                        },
                        {
                           criteria: "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                           versionEndExcluding: "6.12",
                           versionStartIncluding: "6.2",
                           vulnerable: true,
                        },
                     ],
                     negate: false,
                     operator: "OR",
                  },
               ],
            },
         ],
         descriptions: [
            {
               lang: "en",
               value: "In the Linux kernel, the following vulnerability has been resolved:\n\nmm, slub: avoid zeroing kmalloc redzone\n\nSince commit 946fa0dbf2d8 (\"mm/slub: extend redzone check to extra\nallocated kmalloc space than requested\"), setting orig_size treats\nthe wasted space (object_size - orig_size) as a redzone. However with\ninit_on_free=1 we clear the full object->size, including the redzone.\n\nAdditionally we clear the object metadata, including the stored orig_size,\nmaking it zero, which makes check_object() treat the whole object as a\nredzone.\n\nThese issues lead to the following BUG report with \"slub_debug=FUZ\ninit_on_free=1\":\n\n[    0.000000] =============================================================================\n[    0.000000] BUG kmalloc-8 (Not tainted): kmalloc Redzone overwritten\n[    0.000000] -----------------------------------------------------------------------------\n[    0.000000]\n[    0.000000] 0xffff000010032858-0xffff00001003285f @offset=2136. First byte 0x0 instead of 0xcc\n[    0.000000] FIX kmalloc-8: Restoring kmalloc Redzone 0xffff000010032858-0xffff00001003285f=0xcc\n[    0.000000] Slab 0xfffffdffc0400c80 objects=36 used=23 fp=0xffff000010032a18 flags=0x3fffe0000000200(workingset|node=0|zone=0|lastcpupid=0x1ffff)\n[    0.000000] Object 0xffff000010032858 @offset=2136 fp=0xffff0000100328c8\n[    0.000000]\n[    0.000000] Redzone  ffff000010032850: cc cc cc cc cc cc cc cc                          ........\n[    0.000000] Object   ffff000010032858: cc cc cc cc cc cc cc cc                          ........\n[    0.000000] Redzone  ffff000010032860: cc cc cc cc cc cc cc cc                          ........\n[    0.000000] Padding  ffff0000100328b4: 00 00 00 00 00 00 00 00 00 00 00 00              ............\n[    0.000000] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.11.0-rc3-next-20240814-00004-g61844c55c3f4 #144\n[    0.000000] Hardware name: NXP i.MX95 19X19 board (DT)\n[    0.000000] Call trace:\n[    0.000000]  dump_backtrace+0x90/0xe8\n[    0.000000]  show_stack+0x18/0x24\n[    0.000000]  dump_stack_lvl+0x74/0x8c\n[    0.000000]  dump_stack+0x18/0x24\n[    0.000000]  print_trailer+0x150/0x218\n[    0.000000]  check_object+0xe4/0x454\n[    0.000000]  free_to_partial_list+0x2f8/0x5ec\n\nTo address the issue, use orig_size to clear the used area. And restore\nthe value of orig_size after clear the remaining area.\n\nWhen CONFIG_SLUB_DEBUG not defined, (get_orig_size()' directly returns\ns->object_size. So when using memset to init the area, the size can simply\nbe orig_size, as orig_size returns object_size when CONFIG_SLUB_DEBUG not\nenabled. And orig_size can never be bigger than object_size.",
            },
         ],
         providerMetadata: {
            dateUpdated: "2025-05-04T09:40:27.166Z",
            orgId: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            shortName: "Linux",
         },
         references: [
            {
               url: "https://git.kernel.org/stable/c/7a2e823a19746d54052c625faecf0d2d6c52ee0a",
            },
            {
               url: "https://git.kernel.org/stable/c/83f0440b2f92227fcce9898118ca7fe7e0d64b1f",
            },
            {
               url: "https://git.kernel.org/stable/c/59090e479ac78ae18facd4c58eb332562a23020e",
            },
         ],
         title: "mm, slub: avoid zeroing kmalloc redzone",
         x_generator: {
            engine: "bippy-1.2.0",
         },
      },
   },
   cveMetadata: {
      assignerOrgId: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      assignerShortName: "Linux",
      cveId: "CVE-2024-49885",
      datePublished: "2024-10-21T18:01:22.186Z",
      dateReserved: "2024-10-21T12:17:06.022Z",
      dateUpdated: "2025-05-04T09:40:27.166Z",
      state: "PUBLISHED",
   },
   dataType: "CVE_RECORD",
   dataVersion: "5.1",
   "vulnerability-lookup:meta": {
      nvd: "{\"cve\":{\"id\":\"CVE-2024-49885\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2024-10-21T18:15:11.230\",\"lastModified\":\"2024-11-13T14:36:33.207\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nmm, slub: avoid zeroing kmalloc redzone\\n\\nSince commit 946fa0dbf2d8 (\\\"mm/slub: extend redzone check to extra\\nallocated kmalloc space than requested\\\"), setting orig_size treats\\nthe wasted space (object_size - orig_size) as a redzone. However with\\ninit_on_free=1 we clear the full object->size, including the redzone.\\n\\nAdditionally we clear the object metadata, including the stored orig_size,\\nmaking it zero, which makes check_object() treat the whole object as a\\nredzone.\\n\\nThese issues lead to the following BUG report with \\\"slub_debug=FUZ\\ninit_on_free=1\\\":\\n\\n[    0.000000] =============================================================================\\n[    0.000000] BUG kmalloc-8 (Not tainted): kmalloc Redzone overwritten\\n[    0.000000] -----------------------------------------------------------------------------\\n[    0.000000]\\n[    0.000000] 0xffff000010032858-0xffff00001003285f @offset=2136. First byte 0x0 instead of 0xcc\\n[    0.000000] FIX kmalloc-8: Restoring kmalloc Redzone 0xffff000010032858-0xffff00001003285f=0xcc\\n[    0.000000] Slab 0xfffffdffc0400c80 objects=36 used=23 fp=0xffff000010032a18 flags=0x3fffe0000000200(workingset|node=0|zone=0|lastcpupid=0x1ffff)\\n[    0.000000] Object 0xffff000010032858 @offset=2136 fp=0xffff0000100328c8\\n[    0.000000]\\n[    0.000000] Redzone  ffff000010032850: cc cc cc cc cc cc cc cc                          ........\\n[    0.000000] Object   ffff000010032858: cc cc cc cc cc cc cc cc                          ........\\n[    0.000000] Redzone  ffff000010032860: cc cc cc cc cc cc cc cc                          ........\\n[    0.000000] Padding  ffff0000100328b4: 00 00 00 00 00 00 00 00 00 00 00 00              ............\\n[    0.000000] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.11.0-rc3-next-20240814-00004-g61844c55c3f4 #144\\n[    0.000000] Hardware name: NXP i.MX95 19X19 board (DT)\\n[    0.000000] Call trace:\\n[    0.000000]  dump_backtrace+0x90/0xe8\\n[    0.000000]  show_stack+0x18/0x24\\n[    0.000000]  dump_stack_lvl+0x74/0x8c\\n[    0.000000]  dump_stack+0x18/0x24\\n[    0.000000]  print_trailer+0x150/0x218\\n[    0.000000]  check_object+0xe4/0x454\\n[    0.000000]  free_to_partial_list+0x2f8/0x5ec\\n\\nTo address the issue, use orig_size to clear the used area. And restore\\nthe value of orig_size after clear the remaining area.\\n\\nWhen CONFIG_SLUB_DEBUG not defined, (get_orig_size()' directly returns\\ns->object_size. So when using memset to init the area, the size can simply\\nbe orig_size, as orig_size returns object_size when CONFIG_SLUB_DEBUG not\\nenabled. And orig_size can never be bigger than object_size.\"},{\"lang\":\"es\",\"value\":\"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: mm, slub: evitar poner a cero la zona roja de kmalloc Desde el commit 946fa0dbf2d8 (\\\"mm/slub: extender la comprobación de la zona roja a espacio de kmalloc asignado adicional al solicitado\\\"), al establecer orig_size se trata el espacio desperdiciado (object_size - orig_size) como una zona roja. Sin embargo, con init_on_free=1 borramos todo el objeto->size, incluida la zona roja. Además, borramos los metadatos del objeto, incluido el orig_size almacenado, haciéndolo cero, lo que hace que check_object() trate todo el objeto como una zona roja. Estos problemas conducen al siguiente informe de ERROR con \\\"slub_debug=FUZ init_on_free=1\\\": [ 0.000000] ===================================================================================== [ 0.000000] ERROR kmalloc-8 (no contaminado): kmalloc Redzone sobrescrito [ 0.000000] ----------------------------------------------------------------------------- [ 0.000000] [ 0.000000] 0xffff000010032858-0xffff00001003285f @offset=2136. Primer byte 0x0 en lugar de 0xcc [ 0.000000] CORREGIR kmalloc-8: Restaurando kmalloc Redzone 0xffff000010032858-0xffff00001003285f=0xcc [ 0.000000] Losa 0xfffffdffc0400c80 objetos=36 usados=23 fp=0xffff000010032a18 indicadores=0x3fffe0000000200(workingset|node=0|zone=0|lastcpupid=0x1ffff) [ 0.000000] Objeto 0xffff000010032858 @offset=2136 fp=0xffff0000100328c8 [ 0.000000] [ 0.000000] Redzone ffff000010032850: cc cc cc cc cc cc cc cc ........ [ 0.000000] Objeto ffff000010032858: cc cc cc cc cc cc cc cc cc ........ [ 0.000000] Redzone ffff000010032860: cc cc cc cc cc cc cc cc cc ........ [ 0.000000] Relleno ffff0000100328b4: 00 00 00 00 00 00 00 00 00 00 00 00 ............ [ 0.000000] CPU: 0 UID: 0 PID: 0 Comm: intercambiador/0 No contaminado 6.11.0-rc3-next-20240814-00004-g61844c55c3f4 #144 [ 0.000000] Nombre del hardware: Placa NXP i.MX95 19X19 (DT) [ 0.000000] Rastreo de llamadas: [ 0.000000] dump_backtrace+0x90/0xe8 [ 0.000000] show_stack+0x18/0x24 [ 0.000000] dump_stack_lvl+0x74/0x8c [ 0.000000] dump_stack+0x18/0x24 [ 0.000000] print_trailer+0x150/0x218 [ 0.000000] check_object+0xe4/0x454 [ 0.000000] free_to_partial_list+0x2f8/0x5ec Para solucionar el problema, use orig_size para limpiar el área usada. Y restaure el valor de orig_size después de limpiar el área restante. Cuando CONFIG_SLUB_DEBUG no está definido, (get_orig_size()' retorna directamente s->object_size. Entonces, cuando se usa memset para inicializar el área, el tamaño puede ser simplemente orig_size, ya que orig_size retorna object_size cuando CONFIG_SLUB_DEBUG no está habilitado. Y orig_size nunca puede ser mayor que object_size.\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":5.5,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":3.6}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"NVD-CWE-noinfo\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.2\",\"versionEndExcluding\":\"6.10.14\",\"matchCriteriaId\":\"1337614F-3988-4131-AE51-21C855695DE3\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.11\",\"versionEndExcluding\":\"6.11.3\",\"matchCriteriaId\":\"54D9C704-D679-41A7-9C40-10A6B1E7FFE9\"}]}]}],\"references\":[{\"url\":\"https://git.kernel.org/stable/c/59090e479ac78ae18facd4c58eb332562a23020e\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/7a2e823a19746d54052c625faecf0d2d6c52ee0a\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/83f0440b2f92227fcce9898118ca7fe7e0d64b1f\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]}]}}",
      vulnrichment: {
         containers: "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2024-49885\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2024-10-22T13:45:07.682094Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2024-10-22T13:45:10.780Z\"}}], \"cna\": {\"title\": \"mm, slub: avoid zeroing kmalloc redzone\", \"affected\": [{\"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\", \"vendor\": \"Linux\", \"product\": \"Linux\", \"versions\": [{\"status\": \"affected\", \"version\": \"946fa0dbf2d8923a587f7348adf16563d59f1b3d\", \"lessThan\": \"7a2e823a19746d54052c625faecf0d2d6c52ee0a\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"946fa0dbf2d8923a587f7348adf16563d59f1b3d\", \"lessThan\": \"83f0440b2f92227fcce9898118ca7fe7e0d64b1f\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"946fa0dbf2d8923a587f7348adf16563d59f1b3d\", \"lessThan\": \"59090e479ac78ae18facd4c58eb332562a23020e\", \"versionType\": \"git\"}], \"programFiles\": [\"mm/slub.c\"], \"defaultStatus\": \"unaffected\"}, {\"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\", \"vendor\": \"Linux\", \"product\": \"Linux\", \"versions\": [{\"status\": \"affected\", \"version\": \"6.2\"}, {\"status\": \"unaffected\", \"version\": \"0\", \"lessThan\": \"6.2\", \"versionType\": \"semver\"}, {\"status\": \"unaffected\", \"version\": \"6.10.14\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"6.10.*\"}, {\"status\": \"unaffected\", \"version\": \"6.11.3\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"6.11.*\"}, {\"status\": \"unaffected\", \"version\": \"6.12\", \"versionType\": \"original_commit_for_fix\", \"lessThanOrEqual\": \"*\"}], \"programFiles\": [\"mm/slub.c\"], \"defaultStatus\": \"affected\"}], \"references\": [{\"url\": \"https://git.kernel.org/stable/c/7a2e823a19746d54052c625faecf0d2d6c52ee0a\"}, {\"url\": \"https://git.kernel.org/stable/c/83f0440b2f92227fcce9898118ca7fe7e0d64b1f\"}, {\"url\": \"https://git.kernel.org/stable/c/59090e479ac78ae18facd4c58eb332562a23020e\"}], \"x_generator\": {\"engine\": \"bippy-1.2.0\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"In the Linux kernel, the following vulnerability has been resolved:\\n\\nmm, slub: avoid zeroing kmalloc redzone\\n\\nSince commit 946fa0dbf2d8 (\\\"mm/slub: extend redzone check to extra\\nallocated kmalloc space than requested\\\"), setting orig_size treats\\nthe wasted space (object_size - orig_size) as a redzone. However with\\ninit_on_free=1 we clear the full object->size, including the redzone.\\n\\nAdditionally we clear the object metadata, including the stored orig_size,\\nmaking it zero, which makes check_object() treat the whole object as a\\nredzone.\\n\\nThese issues lead to the following BUG report with \\\"slub_debug=FUZ\\ninit_on_free=1\\\":\\n\\n[    0.000000] =============================================================================\\n[    0.000000] BUG kmalloc-8 (Not tainted): kmalloc Redzone overwritten\\n[    0.000000] -----------------------------------------------------------------------------\\n[    0.000000]\\n[    0.000000] 0xffff000010032858-0xffff00001003285f @offset=2136. First byte 0x0 instead of 0xcc\\n[    0.000000] FIX kmalloc-8: Restoring kmalloc Redzone 0xffff000010032858-0xffff00001003285f=0xcc\\n[    0.000000] Slab 0xfffffdffc0400c80 objects=36 used=23 fp=0xffff000010032a18 flags=0x3fffe0000000200(workingset|node=0|zone=0|lastcpupid=0x1ffff)\\n[    0.000000] Object 0xffff000010032858 @offset=2136 fp=0xffff0000100328c8\\n[    0.000000]\\n[    0.000000] Redzone  ffff000010032850: cc cc cc cc cc cc cc cc                          ........\\n[    0.000000] Object   ffff000010032858: cc cc cc cc cc cc cc cc                          ........\\n[    0.000000] Redzone  ffff000010032860: cc cc cc cc cc cc cc cc                          ........\\n[    0.000000] Padding  ffff0000100328b4: 00 00 00 00 00 00 00 00 00 00 00 00              ............\\n[    0.000000] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.11.0-rc3-next-20240814-00004-g61844c55c3f4 #144\\n[    0.000000] Hardware name: NXP i.MX95 19X19 board (DT)\\n[    0.000000] Call trace:\\n[    0.000000]  dump_backtrace+0x90/0xe8\\n[    0.000000]  show_stack+0x18/0x24\\n[    0.000000]  dump_stack_lvl+0x74/0x8c\\n[    0.000000]  dump_stack+0x18/0x24\\n[    0.000000]  print_trailer+0x150/0x218\\n[    0.000000]  check_object+0xe4/0x454\\n[    0.000000]  free_to_partial_list+0x2f8/0x5ec\\n\\nTo address the issue, use orig_size to clear the used area. And restore\\nthe value of orig_size after clear the remaining area.\\n\\nWhen CONFIG_SLUB_DEBUG not defined, (get_orig_size()' directly returns\\ns->object_size. So when using memset to init the area, the size can simply\\nbe orig_size, as orig_size returns object_size when CONFIG_SLUB_DEBUG not\\nenabled. And orig_size can never be bigger than object_size.\"}], \"cpeApplicability\": [{\"nodes\": [{\"negate\": false, \"cpeMatch\": [{\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"6.10.14\", \"versionStartIncluding\": \"6.2\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"6.11.3\", \"versionStartIncluding\": \"6.2\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"6.12\", \"versionStartIncluding\": \"6.2\"}], \"operator\": \"OR\"}]}], \"providerMetadata\": {\"orgId\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\", \"shortName\": \"Linux\", \"dateUpdated\": \"2025-05-04T09:40:27.166Z\"}}}",
         cveMetadata: "{\"cveId\": \"CVE-2024-49885\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2025-05-04T09:40:27.166Z\", \"dateReserved\": \"2024-10-21T12:17:06.022Z\", \"assignerOrgId\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\", \"datePublished\": \"2024-10-21T18:01:22.186Z\", \"assignerShortName\": \"Linux\"}",
         dataType: "CVE_RECORD",
         dataVersion: "5.1",
      },
   },
}


Log in or create an account to share your comment.

Security Advisory comment format.

This schema specifies the format of a comment related to a security advisory.

UUIDv4 of the comment
UUIDv4 of the Vulnerability-Lookup instance
When the comment was created originally
When the comment was last updated
Title of the comment
Description of the comment
The identifier of the vulnerability (CVE ID, GHSA-ID, PYSEC ID, etc.).



Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.