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CVE-2021-47531 (GCVE-0-2021-47531)

Vulnerability from cvelistv5 – Published: 2024-05-24 15:09 – Updated: 2026-05-11 13:56

Title

drm/msm: Fix mmap to include VM_IO and VM_DONTDUMP

Summary

In the Linux kernel, the following vulnerability has been resolved: drm/msm: Fix mmap to include VM_IO and VM_DONTDUMP In commit 510410bfc034 ("drm/msm: Implement mmap as GEM object function") we switched to a new/cleaner method of doing things. That's good, but we missed a little bit. Before that commit, we used to _first_ run through the drm_gem_mmap_obj() case where `obj->funcs->mmap()` was NULL. That meant that we ran: vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP; vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags)); vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot); ...and _then_ we modified those mappings with our own. Now that `obj->funcs->mmap()` is no longer NULL we don't run the default code. It looks like the fact that the vm_flags got VM_IO / VM_DONTDUMP was important because we're now getting crashes on Chromebooks that use ARC++ while logging out. Specifically a crash that looks like this (this is on a 5.10 kernel w/ relevant backports but also seen on a 5.15 kernel): Unable to handle kernel paging request at virtual address ffffffc008000000 Mem abort info: ESR = 0x96000006 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000006 CM = 0, WnR = 0 swapper pgtable: 4k pages, 39-bit VAs, pgdp=000000008293d000 [ffffffc008000000] pgd=00000001002b3003, p4d=00000001002b3003, pud=00000001002b3003, pmd=0000000000000000 Internal error: Oops: 96000006 [#1] PREEMPT SMP [...] CPU: 7 PID: 15734 Comm: crash_dump64 Tainted: G W 5.10.67 #1 [...] Hardware name: Qualcomm Technologies, Inc. sc7280 IDP SKU2 platform (DT) pstate: 80400009 (Nzcv daif +PAN -UAO -TCO BTYPE=--) pc : __arch_copy_to_user+0xc0/0x30c lr : copyout+0xac/0x14c [...] Call trace: __arch_copy_to_user+0xc0/0x30c copy_page_to_iter+0x1a0/0x294 process_vm_rw_core+0x240/0x408 process_vm_rw+0x110/0x16c __arm64_sys_process_vm_readv+0x30/0x3c el0_svc_common+0xf8/0x250 do_el0_svc+0x30/0x80 el0_svc+0x10/0x1c el0_sync_handler+0x78/0x108 el0_sync+0x184/0x1c0 Code: f8408423 f80008c3 910020c6 36100082 (b8404423) Let's add the two flags back in. While we're at it, the fact that we aren't running the default means that we _don't_ need to clear out VM_PFNMAP, so remove that and save an instruction. NOTE: it was confirmed that VM_IO was the important flag to fix the problem I was seeing, but adding back VM_DONTDUMP seems like a sane thing to do so I'm doing that too.

Severity

No CVSS data available.

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2024-09-10 15:35 UTC

Assigner

Linux mitre root

References

2 references

URL	Tags
https://git.kernel.org/stable/c/8e2b7fe5e8a4be5e5…
https://git.kernel.org/stable/c/3466d9e217b337bf4…

Impacted products

2 products

Vendor	Product	Version	CPE status
Linux	Linux	Affected: 510410bfc034c57cc3caf1572aa47c1017bab2f9 , < 8e2b7fe5e8a4be5e571561d9afcfbd92097288ba (git) Affected: 510410bfc034c57cc3caf1572aa47c1017bab2f9 , < 3466d9e217b337bf473ee629c608e53f9f3ab786 (git)	guessed
Linux	Linux	Affected: 5.15 Unaffected: 0 , < 5.15 (semver) Unaffected: 5.15.7 , ≤ 5.15.* (semver) Unaffected: 5.16 , ≤ * (original_commit_for_fix)	guessed

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      "descriptions": "[{\"lang\": \"en\", \"value\": \"In the Linux kernel, the following vulnerability has been resolved:\\n\\ndrm/msm: Fix mmap to include VM_IO and VM_DONTDUMP\\n\\nIn commit 510410bfc034 (\\\"drm/msm: Implement mmap as GEM object\\nfunction\\\") we switched to a new/cleaner method of doing things. That\u0027s\\ngood, but we missed a little bit.\\n\\nBefore that commit, we used to _first_ run through the\\ndrm_gem_mmap_obj() case where `obj-\u003efuncs-\u003emmap()` was NULL. That meant\\nthat we ran:\\n\\n  vma-\u003evm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;\\n  vma-\u003evm_page_prot = pgprot_writecombine(vm_get_page_prot(vma-\u003evm_flags));\\n  vma-\u003evm_page_prot = pgprot_decrypted(vma-\u003evm_page_prot);\\n\\n...and _then_ we modified those mappings with our own. Now that\\n`obj-\u003efuncs-\u003emmap()` is no longer NULL we don\u0027t run the default\\ncode. It looks like the fact that the vm_flags got VM_IO / VM_DONTDUMP\\nwas important because we\u0027re now getting crashes on Chromebooks that\\nuse ARC++ while logging out. Specifically a crash that looks like this\\n(this is on a 5.10 kernel w/ relevant backports but also seen on a\\n5.15 kernel):\\n\\n  Unable to handle kernel paging request at virtual address ffffffc008000000\\n  Mem abort info:\\n    ESR = 0x96000006\\n    EC = 0x25: DABT (current EL), IL = 32 bits\\n    SET = 0, FnV = 0\\n    EA = 0, S1PTW = 0\\n  Data abort info:\\n    ISV = 0, ISS = 0x00000006\\n    CM = 0, WnR = 0\\n  swapper pgtable: 4k pages, 39-bit VAs, pgdp=000000008293d000\\n  [ffffffc008000000] pgd=00000001002b3003, p4d=00000001002b3003,\\n                     pud=00000001002b3003, pmd=0000000000000000\\n  Internal error: Oops: 96000006 [#1] PREEMPT SMP\\n  [...]\\n  CPU: 7 PID: 15734 Comm: crash_dump64 Tainted: G W 5.10.67 #1 [...]\\n  Hardware name: Qualcomm Technologies, Inc. sc7280 IDP SKU2 platform (DT)\\n  pstate: 80400009 (Nzcv daif +PAN -UAO -TCO BTYPE=--)\\n  pc : __arch_copy_to_user+0xc0/0x30c\\n  lr : copyout+0xac/0x14c\\n  [...]\\n  Call trace:\\n   __arch_copy_to_user+0xc0/0x30c\\n   copy_page_to_iter+0x1a0/0x294\\n   process_vm_rw_core+0x240/0x408\\n   process_vm_rw+0x110/0x16c\\n   __arm64_sys_process_vm_readv+0x30/0x3c\\n   el0_svc_common+0xf8/0x250\\n   do_el0_svc+0x30/0x80\\n   el0_svc+0x10/0x1c\\n   el0_sync_handler+0x78/0x108\\n   el0_sync+0x184/0x1c0\\n  Code: f8408423 f80008c3 910020c6 36100082 (b8404423)\\n\\nLet\u0027s add the two flags back in.\\n\\nWhile we\u0027re at it, the fact that we aren\u0027t running the default means\\nthat we _don\u0027t_ need to clear out VM_PFNMAP, so remove that and save\\nan instruction.\\n\\nNOTE: it was confirmed that VM_IO was the important flag to fix the\\nproblem I was seeing, but adding back VM_DONTDUMP seems like a sane\\nthing to do so I\u0027m doing that too.\"}, {\"lang\": \"es\", \"value\": \"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: drm/msm: corrige mmap para incluir VM_IO y VM_DONTDUMP. En el commit 510410bfc034 (\\\"drm/msm: implementa mmap como funci\\u00f3n de objeto GEM\\\") Nosotros cambiamos a un m\\u00e9todo nuevo / m\\u00e1s limpio de hacer las cosas. Eso es bueno, pero nos perdimos un poquito. Antes de esa confirmaci\\u00f3n, sol\\u00edamos ejecutar _primero_ el caso drm_gem_mmap_obj() donde `obj-\u0026gt;funcs-\u0026gt;mmap()` era NULL. Eso signific\\u00f3 que ejecutamos: vma-\u0026gt;vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP; vma-\u0026gt;vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma-\u0026gt;vm_flags)); vma-\u0026gt;vm_page_prot = pgprot_decrypted(vma-\u0026gt;vm_page_prot); ...y _luego_ modificamos esas asignaciones con las nuestras. Ahora que `obj-\u0026gt;funcs-\u0026gt;mmap()` ya no es NULL, no ejecutamos el c\\u00f3digo predeterminado. Parece que el hecho de que vm_flags obtuviera VM_IO/VM_DONTDUMP fue importante porque ahora estamos teniendo fallas en Chromebooks que usan ARC++ al cerrar sesi\\u00f3n. Espec\\u00edficamente, un bloqueo que se ve as\\u00ed (esto ocurre en un kernel 5.10 con backports relevantes, pero tambi\\u00e9n se ve en un kernel 5.15): No se puede manejar la solicitud de paginaci\\u00f3n del kernel en la direcci\\u00f3n virtual ffffffc008000000 Informaci\\u00f3n de cancelaci\\u00f3n de memoria: ESR = 0x96000006 EC = 0x25: DABT ( EL actual), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Informaci\\u00f3n de cancelaci\\u00f3n de datos: ISV = 0, ISS = 0x00000006 CM = 0, WnR = 0 tabla de intercambio: 4k p\\u00e1ginas, VA de 39 bits , pgdp=000000008293d000 [ffffffc008000000] pgd=00000001002b3003, p4d=00000001002b3003, pud=00000001002b3003, pmd=0000000000000000 Error interno: operaciones: 96000006 [#1] PREEMPT SMP [...] CPU: 7 PID: 15734 Comunicaciones: crash_dump64 Contaminado: GW 5.10.67 #1 [...] Nombre del hardware: Qualcomm Technologies, Inc. sc7280 IDP SKU2 plataforma (DT) pstate: 80400009 (Nzcv daif +PAN -UAO -TCO BTYPE=--) pc: __arch_copy_to_user+0xc0/0x30c lr: copyout+0xac/0x14c [...] Rastreo de llamadas: __arch_copy_to_user+0xc0/0x30c copy_page_to_iter+0x1a0/0x294 Process_vm_rw_core+0x240/0x408 Process_vm_rw+0x110/0x16c __arm64_sys_process_vm_readv+0x30/0 x3c el0_svc_common+0xf8/0x250 do_el0_svc+0x30/0x80 el0_svc+0x10/0x1c el0_sync_handler+0x78/0x108 el0_sync+0x184/0x1c0 C\\u00f3digo: f8408423 f80008c3 910020c6 36100082 (b8404423) Agreguemos las dos banderas nuevamente. Mientras estamos en esto, el hecho de que no estemos ejecutando medios predeterminados que _no_ necesitamos borrar VM_PFNMAP, as\\u00ed que elim\\u00ednelo y guarde una instrucci\\u00f3n. NOTA: se confirm\\u00f3 que VM_IO era el indicador importante para solucionar el problema que estaba viendo, pero volver a agregar VM_DONTDUMP parece algo sensato, as\\u00ed que lo estoy haciendo tambi\\u00e9n.\"}]",
      "id": "CVE-2021-47531",
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      "published": "2024-05-24T15:15:16.357",
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    "nvd": "{\"cve\":{\"id\":\"CVE-2021-47531\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2024-05-24T15:15:16.357\",\"lastModified\":\"2026-06-17T04:17:42.267\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\ndrm/msm: Fix mmap to include VM_IO and VM_DONTDUMP\\n\\nIn commit 510410bfc034 (\\\"drm/msm: Implement mmap as GEM object\\nfunction\\\") we switched to a new/cleaner method of doing things. That\u0027s\\ngood, but we missed a little bit.\\n\\nBefore that commit, we used to _first_ run through the\\ndrm_gem_mmap_obj() case where `obj-\u003efuncs-\u003emmap()` was NULL. That meant\\nthat we ran:\\n\\n  vma-\u003evm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;\\n  vma-\u003evm_page_prot = pgprot_writecombine(vm_get_page_prot(vma-\u003evm_flags));\\n  vma-\u003evm_page_prot = pgprot_decrypted(vma-\u003evm_page_prot);\\n\\n...and _then_ we modified those mappings with our own. Now that\\n`obj-\u003efuncs-\u003emmap()` is no longer NULL we don\u0027t run the default\\ncode. It looks like the fact that the vm_flags got VM_IO / VM_DONTDUMP\\nwas important because we\u0027re now getting crashes on Chromebooks that\\nuse ARC++ while logging out. Specifically a crash that looks like this\\n(this is on a 5.10 kernel w/ relevant backports but also seen on a\\n5.15 kernel):\\n\\n  Unable to handle kernel paging request at virtual address ffffffc008000000\\n  Mem abort info:\\n    ESR = 0x96000006\\n    EC = 0x25: DABT (current EL), IL = 32 bits\\n    SET = 0, FnV = 0\\n    EA = 0, S1PTW = 0\\n  Data abort info:\\n    ISV = 0, ISS = 0x00000006\\n    CM = 0, WnR = 0\\n  swapper pgtable: 4k pages, 39-bit VAs, pgdp=000000008293d000\\n  [ffffffc008000000] pgd=00000001002b3003, p4d=00000001002b3003,\\n                     pud=00000001002b3003, pmd=0000000000000000\\n  Internal error: Oops: 96000006 [#1] PREEMPT SMP\\n  [...]\\n  CPU: 7 PID: 15734 Comm: crash_dump64 Tainted: G W 5.10.67 #1 [...]\\n  Hardware name: Qualcomm Technologies, Inc. sc7280 IDP SKU2 platform (DT)\\n  pstate: 80400009 (Nzcv daif +PAN -UAO -TCO BTYPE=--)\\n  pc : __arch_copy_to_user+0xc0/0x30c\\n  lr : copyout+0xac/0x14c\\n  [...]\\n  Call trace:\\n   __arch_copy_to_user+0xc0/0x30c\\n   copy_page_to_iter+0x1a0/0x294\\n   process_vm_rw_core+0x240/0x408\\n   process_vm_rw+0x110/0x16c\\n   __arm64_sys_process_vm_readv+0x30/0x3c\\n   el0_svc_common+0xf8/0x250\\n   do_el0_svc+0x30/0x80\\n   el0_svc+0x10/0x1c\\n   el0_sync_handler+0x78/0x108\\n   el0_sync+0x184/0x1c0\\n  Code: f8408423 f80008c3 910020c6 36100082 (b8404423)\\n\\nLet\u0027s add the two flags back in.\\n\\nWhile we\u0027re at it, the fact that we aren\u0027t running the default means\\nthat we _don\u0027t_ need to clear out VM_PFNMAP, so remove that and save\\nan instruction.\\n\\nNOTE: it was confirmed that VM_IO was the important flag to fix the\\nproblem I was seeing, but adding back VM_DONTDUMP seems like a sane\\nthing to do so I\u0027m doing that too.\"},{\"lang\":\"es\",\"value\":\"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: drm/msm: corrige mmap para incluir VM_IO y VM_DONTDUMP. En el commit 510410bfc034 (\\\"drm/msm: implementa mmap como funci\u00f3n de objeto GEM\\\") Nosotros cambiamos a un m\u00e9todo nuevo / m\u00e1s limpio de hacer las cosas. Eso es bueno, pero nos perdimos un poquito. Antes de esa confirmaci\u00f3n, sol\u00edamos ejecutar _primero_ el caso drm_gem_mmap_obj() donde `obj-\u0026gt;funcs-\u0026gt;mmap()` era NULL. Eso signific\u00f3 que ejecutamos: vma-\u0026gt;vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP; vma-\u0026gt;vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma-\u0026gt;vm_flags)); vma-\u0026gt;vm_page_prot = pgprot_decrypted(vma-\u0026gt;vm_page_prot); ...y _luego_ modificamos esas asignaciones con las nuestras. Ahora que `obj-\u0026gt;funcs-\u0026gt;mmap()` ya no es NULL, no ejecutamos el c\u00f3digo predeterminado. Parece que el hecho de que vm_flags obtuviera VM_IO/VM_DONTDUMP fue importante porque ahora estamos teniendo fallas en Chromebooks que usan ARC++ al cerrar sesi\u00f3n. Espec\u00edficamente, un bloqueo que se ve as\u00ed (esto ocurre en un kernel 5.10 con backports relevantes, pero tambi\u00e9n se ve en un kernel 5.15): No se puede manejar la solicitud de paginaci\u00f3n del kernel en la direcci\u00f3n virtual ffffffc008000000 Informaci\u00f3n de cancelaci\u00f3n de memoria: ESR = 0x96000006 EC = 0x25: DABT ( EL actual), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Informaci\u00f3n de cancelaci\u00f3n de datos: ISV = 0, ISS = 0x00000006 CM = 0, WnR = 0 tabla de intercambio: 4k p\u00e1ginas, VA de 39 bits , pgdp=000000008293d000 [ffffffc008000000] pgd=00000001002b3003, p4d=00000001002b3003, pud=00000001002b3003, pmd=0000000000000000 Error interno: operaciones: 96000006 [#1] PREEMPT SMP [...] CPU: 7 PID: 15734 Comunicaciones: crash_dump64 Contaminado: GW 5.10.67 #1 [...] Nombre del hardware: Qualcomm Technologies, Inc. sc7280 IDP SKU2 plataforma (DT) pstate: 80400009 (Nzcv daif +PAN -UAO -TCO BTYPE=--) pc: __arch_copy_to_user+0xc0/0x30c lr: copyout+0xac/0x14c [...] Rastreo de llamadas: __arch_copy_to_user+0xc0/0x30c copy_page_to_iter+0x1a0/0x294 Process_vm_rw_core+0x240/0x408 Process_vm_rw+0x110/0x16c __arm64_sys_process_vm_readv+0x30/0 x3c el0_svc_common+0xf8/0x250 do_el0_svc+0x30/0x80 el0_svc+0x10/0x1c el0_sync_handler+0x78/0x108 el0_sync+0x184/0x1c0 C\u00f3digo: f8408423 f80008c3 910020c6 36100082 (b8404423) Agreguemos las dos banderas nuevamente. Mientras estamos en esto, el hecho de que no estemos ejecutando medios predeterminados que _no_ necesitamos borrar VM_PFNMAP, as\u00ed que elim\u00ednelo y guarde una instrucci\u00f3n. NOTA: se confirm\u00f3 que VM_IO era el indicador importante para solucionar el problema que estaba viendo, pero volver a agregar VM_DONTDUMP parece algo sensato, as\u00ed que lo estoy haciendo tambi\u00e9n.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"drivers/gpu/drm/msm/msm_gem.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"510410bfc034c57cc3caf1572aa47c1017bab2f9\",\"lessThan\":\"8e2b7fe5e8a4be5e571561d9afcfbd92097288ba\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"510410bfc034c57cc3caf1572aa47c1017bab2f9\",\"lessThan\":\"3466d9e217b337bf473ee629c608e53f9f3ab786\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"drivers/gpu/drm/msm/msm_gem.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"5.15\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"5.15\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.7\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.16\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"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}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2024-09-10T15:35:23.631797Z\",\"id\":\"CVE-2021-47531\",\"options\":[{\"exploitation\":\"none\"},{\"automatable\":\"no\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"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\":\"5.15\",\"versionEndExcluding\":\"5.15.7\",\"matchCriteriaId\":\"E524C2AB-B061-43A9-8F32-C09C86BC2479\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:5.16:rc1:*:*:*:*:*:*\",\"matchCriteriaId\":\"357AA433-37E8-4323-BFB2-3038D6E4B414\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:5.16:rc2:*:*:*:*:*:*\",\"matchCriteriaId\":\"A73429BA-C2D9-4D0C-A75F-06A1CA8B3983\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:5.16:rc3:*:*:*:*:*:*\",\"matchCriteriaId\":\"F621B5E3-E99D-49E7-90B9-EC3B77C95383\"}]}]}],\"references\":[{\"url\":\"https://git.kernel.org/stable/c/3466d9e217b337bf473ee629c608e53f9f3ab786\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/8e2b7fe5e8a4be5e571561d9afcfbd92097288ba\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/3466d9e217b337bf473ee629c608e53f9f3ab786\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/8e2b7fe5e8a4be5e571561d9afcfbd92097288ba\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Patch\"]}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2025-11-21T10:48:04+00:00",
      "cve": "CVE-2021-47531",
      "id": "CVE-2021-47531",
      "initial_release_date": "2021-01-01T00:00:00+00:00",
      "product_status:known_not_affected": "198",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: drm/msm: Fix mmap to include VM_IO and VM_DONTDUMP",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-47531.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-09-11T02:37:28Z",
      "cve": "CVE-2021-47531",
      "id": "CVE-2021-47531",
      "initial_release_date": "2024-05-28T15:29:42Z",
      "product_status:known_affected": "315",
      "product_status:known_not_affected": "323",
      "product_status:recommended": "313",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2021-47531",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2021-47531.json",
      "version": "53"
    },
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CVE Program Container\", \"references\": [{\"url\": \"https://git.kernel.org/stable/c/8e2b7fe5e8a4be5e571561d9afcfbd92097288ba\", \"tags\": [\"x_transferred\"]}, {\"url\": \"https://git.kernel.org/stable/c/3466d9e217b337bf473ee629c608e53f9f3ab786\", \"tags\": [\"x_transferred\"]}], \"providerMetadata\": {\"orgId\": \"af854a3a-2127-422b-91ae-364da2661108\", \"shortName\": \"CVE\", \"dateUpdated\": \"2024-08-04T05:39:59.773Z\"}}, {\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2021-47531\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2024-09-10T15:35:23.631797Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2024-09-11T12:42:16.295Z\"}}], \"cna\": {\"title\": \"drm/msm: Fix mmap to include VM_IO and VM_DONTDUMP\", \"affected\": [{\"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\", \"vendor\": \"Linux\", \"product\": \"Linux\", \"versions\": [{\"status\": \"affected\", \"version\": \"510410bfc034c57cc3caf1572aa47c1017bab2f9\", \"lessThan\": \"8e2b7fe5e8a4be5e571561d9afcfbd92097288ba\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"510410bfc034c57cc3caf1572aa47c1017bab2f9\", \"lessThan\": \"3466d9e217b337bf473ee629c608e53f9f3ab786\", \"versionType\": \"git\"}], \"programFiles\": [\"drivers/gpu/drm/msm/msm_gem.c\"], \"defaultStatus\": \"unaffected\"}, {\"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\", \"vendor\": \"Linux\", \"product\": \"Linux\", \"versions\": [{\"status\": \"affected\", \"version\": \"5.15\"}, {\"status\": \"unaffected\", \"version\": \"0\", \"lessThan\": \"5.15\", \"versionType\": \"semver\"}, {\"status\": \"unaffected\", \"version\": \"5.15.7\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"5.15.*\"}, {\"status\": \"unaffected\", \"version\": \"5.16\", \"versionType\": \"original_commit_for_fix\", \"lessThanOrEqual\": \"*\"}], \"programFiles\": [\"drivers/gpu/drm/msm/msm_gem.c\"], \"defaultStatus\": \"affected\"}], \"references\": [{\"url\": \"https://git.kernel.org/stable/c/8e2b7fe5e8a4be5e571561d9afcfbd92097288ba\"}, {\"url\": \"https://git.kernel.org/stable/c/3466d9e217b337bf473ee629c608e53f9f3ab786\"}], \"x_generator\": {\"engine\": \"bippy-1.2.0\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"In the Linux kernel, the following vulnerability has been resolved:\\n\\ndrm/msm: Fix mmap to include VM_IO and VM_DONTDUMP\\n\\nIn commit 510410bfc034 (\\\"drm/msm: Implement mmap as GEM object\\nfunction\\\") we switched to a new/cleaner method of doing things. That\u0027s\\ngood, but we missed a little bit.\\n\\nBefore that commit, we used to _first_ run through the\\ndrm_gem_mmap_obj() case where `obj-\u003efuncs-\u003emmap()` was NULL. That meant\\nthat we ran:\\n\\n  vma-\u003evm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;\\n  vma-\u003evm_page_prot = pgprot_writecombine(vm_get_page_prot(vma-\u003evm_flags));\\n  vma-\u003evm_page_prot = pgprot_decrypted(vma-\u003evm_page_prot);\\n\\n...and _then_ we modified those mappings with our own. Now that\\n`obj-\u003efuncs-\u003emmap()` is no longer NULL we don\u0027t run the default\\ncode. It looks like the fact that the vm_flags got VM_IO / VM_DONTDUMP\\nwas important because we\u0027re now getting crashes on Chromebooks that\\nuse ARC++ while logging out. Specifically a crash that looks like this\\n(this is on a 5.10 kernel w/ relevant backports but also seen on a\\n5.15 kernel):\\n\\n  Unable to handle kernel paging request at virtual address ffffffc008000000\\n  Mem abort info:\\n    ESR = 0x96000006\\n    EC = 0x25: DABT (current EL), IL = 32 bits\\n    SET = 0, FnV = 0\\n    EA = 0, S1PTW = 0\\n  Data abort info:\\n    ISV = 0, ISS = 0x00000006\\n    CM = 0, WnR = 0\\n  swapper pgtable: 4k pages, 39-bit VAs, pgdp=000000008293d000\\n  [ffffffc008000000] pgd=00000001002b3003, p4d=00000001002b3003,\\n                     pud=00000001002b3003, pmd=0000000000000000\\n  Internal error: Oops: 96000006 [#1] PREEMPT SMP\\n  [...]\\n  CPU: 7 PID: 15734 Comm: crash_dump64 Tainted: G W 5.10.67 #1 [...]\\n  Hardware name: Qualcomm Technologies, Inc. sc7280 IDP SKU2 platform (DT)\\n  pstate: 80400009 (Nzcv daif +PAN -UAO -TCO BTYPE=--)\\n  pc : __arch_copy_to_user+0xc0/0x30c\\n  lr : copyout+0xac/0x14c\\n  [...]\\n  Call trace:\\n   __arch_copy_to_user+0xc0/0x30c\\n   copy_page_to_iter+0x1a0/0x294\\n   process_vm_rw_core+0x240/0x408\\n   process_vm_rw+0x110/0x16c\\n   __arm64_sys_process_vm_readv+0x30/0x3c\\n   el0_svc_common+0xf8/0x250\\n   do_el0_svc+0x30/0x80\\n   el0_svc+0x10/0x1c\\n   el0_sync_handler+0x78/0x108\\n   el0_sync+0x184/0x1c0\\n  Code: f8408423 f80008c3 910020c6 36100082 (b8404423)\\n\\nLet\u0027s add the two flags back in.\\n\\nWhile we\u0027re at it, the fact that we aren\u0027t running the default means\\nthat we _don\u0027t_ need to clear out VM_PFNMAP, so remove that and save\\nan instruction.\\n\\nNOTE: it was confirmed that VM_IO was the important flag to fix the\\nproblem I was seeing, but adding back VM_DONTDUMP seems like a sane\\nthing to do so I\u0027m doing that too.\"}], \"cpeApplicability\": [{\"nodes\": [{\"negate\": false, \"cpeMatch\": [{\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"5.15.7\", \"versionStartIncluding\": \"5.15\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"5.16\", \"versionStartIncluding\": \"5.15\"}], \"operator\": \"OR\"}]}], \"providerMetadata\": {\"orgId\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\", \"shortName\": \"Linux\", \"dateUpdated\": \"2025-05-04T07:12:58.096Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2021-47531\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2025-05-04T07:12:58.096Z\", \"dateReserved\": \"2024-05-24T15:02:54.826Z\", \"assignerOrgId\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\", \"datePublished\": \"2024-05-24T15:09:41.360Z\", \"assignerShortName\": \"Linux\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.1"
    }
  }
}

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.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

Action not permitted

CVE-2021-47531 (GCVE-0-2021-47531)

WID-SEC-W-2024-1235

Tags

Sightings

Nomenclature