CVE-2021-47623

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2021-47623
In the Linux kernel, the following vulnerability has been resolved: powerpc/fixmap: Fix VM debug warning on unmap Unmapping a fixmap entry is done by calling __set_fixmap() with FIXMAP_PAGE_CLEAR as flags. Today, powerpc __set_fixmap() calls map_kernel_page(). map_kernel_page() is not happy when called a second time for the same page. WARNING: CPU: 0 PID: 1 at arch/powerpc/mm/pgtable.c:194 set_pte_at+0xc/0x1e8 CPU: 0 PID: 1 Comm: swapper Not tainted 5.16.0-rc3-s3k-dev-01993-g350ff07feb7d-dirty #682 NIP: c0017cd4 LR: c00187f0 CTR: 00000010 REGS: e1011d50 TRAP: 0700 Not tainted (5.16.0-rc3-s3k-dev-01993-g350ff07feb7d-dirty) MSR: 00029032 <EE,ME,IR,DR,RI> CR: 42000208 XER: 00000000 GPR00: c0165fec e1011e10 c14c0000 c0ee2550 ff800000 c0f3d000 00000000 c001686c GPR08: 00001000 b00045a9 00000001 c0f58460 c0f50000 00000000 c0007e10 00000000 GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 GPR24: 00000000 00000000 c0ee2550 00000000 c0f57000 00000ff8 00000000 ff800000 NIP [c0017cd4] set_pte_at+0xc/0x1e8 LR [c00187f0] map_kernel_page+0x9c/0x100 Call Trace: [e1011e10] [c0736c68] vsnprintf+0x358/0x6c8 (unreliable) [e1011e30] [c0165fec] __set_fixmap+0x30/0x44 [e1011e40] [c0c13bdc] early_iounmap+0x11c/0x170 [e1011e70] [c0c06cb0] ioremap_legacy_serial_console+0x88/0xc0 [e1011e90] [c0c03634] do_one_initcall+0x80/0x178 [e1011ef0] [c0c0385c] kernel_init_freeable+0xb4/0x250 [e1011f20] [c0007e34] kernel_init+0x24/0x140 [e1011f30] [c0016268] ret_from_kernel_thread+0x5c/0x64 Instruction dump: 7fe3fb78 48019689 80010014 7c630034 83e1000c 5463d97e 7c0803a6 38210010 4e800020 81250000 712a0001 41820008 <0fe00000> 9421ffe0 93e1001c 48000030 Implement unmap_kernel_page() which clears an existing pte.

5.5 /10

CVSS v3 : MEDIUM

V3 Legend

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://git.kernel.org/stable/c/033fd42c18d9b2121595b6f1e8419a115f9ac5b7 Patch
https://git.kernel.org/stable/c/43ae0ccc4d2722b833fb59b905af129428e06d03 Patch
https://git.kernel.org/stable/c/67baac10dd5ad1e9f50e8f2659984b3b0728d54e Patch
https://git.kernel.org/stable/c/aec982603aa8cc0a21143681feb5f60ecc69d718 Patch
https://git.kernel.org/stable/c/033fd42c18d9b2121595b6f1e8419a115f9ac5b7 Patch
https://git.kernel.org/stable/c/43ae0ccc4d2722b833fb59b905af129428e06d03 Patch
https://git.kernel.org/stable/c/67baac10dd5ad1e9f50e8f2659984b3b0728d54e Patch
https://git.kernel.org/stable/c/aec982603aa8cc0a21143681feb5f60ecc69d718 Patch
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.17:rc1:*:*:*:*:*:*
History

03 Oct 2025, 14:30

Type Values Removed Values Added
References () https://git.kernel.org/stable/c/033fd42c18d9b2121595b6f1e8419a115f9ac5b7 - () https://git.kernel.org/stable/c/033fd42c18d9b2121595b6f1e8419a115f9ac5b7 - Patch
References () https://git.kernel.org/stable/c/43ae0ccc4d2722b833fb59b905af129428e06d03 - () https://git.kernel.org/stable/c/43ae0ccc4d2722b833fb59b905af129428e06d03 - Patch
References () https://git.kernel.org/stable/c/67baac10dd5ad1e9f50e8f2659984b3b0728d54e - () https://git.kernel.org/stable/c/67baac10dd5ad1e9f50e8f2659984b3b0728d54e - Patch
References () https://git.kernel.org/stable/c/aec982603aa8cc0a21143681feb5f60ecc69d718 - () https://git.kernel.org/stable/c/aec982603aa8cc0a21143681feb5f60ecc69d718 - Patch
CWE NVD-CWE-noinfo
First Time Linux linux Kernel
Linux
CPE cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.17:rc1:*:*:*:*:*:*
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 5.5

21 Nov 2024, 06:36

Type Values Removed Values Added
Summary
  • (es) En el kernel de Linux, se resolvió la siguiente vulnerabilidad: powerpc/fixmap: corrige la advertencia de depuración de VM al desasignar La desasignación de una entrada de fixmap se realiza llamando a __set_fixmap() con FIXMAP_PAGE_CLEAR como indicadores. Hoy, powerpc __set_fixmap() llama a map_kernel_page(). map_kernel_page() no está contento cuando se le llama por segunda vez para la misma página. ADVERTENCIA: CPU: 0 PID: 1 en arch/powerpc/mm/pgtable.c:194 set_pte_at+0xc/0x1e8 CPU: 0 PID: 1 Comm: swapper No contaminado 5.16.0-rc3-s3k-dev-01993-g350ff07feb7d- sucio #682 NIP: c0017cd4 LR: c00187f0 CTR: 00000010 REGS: e1011d50 TRAP: 0700 No contaminado (5.16.0-rc3-s3k-dev-01993-g350ff07feb7d-dirty) MSR: 00029032 CR: 42000208 XER: 00000000 GPR00: c0165fec e1011e10 c14c0000 c0ee2550 ff800000 c0f3d000 00000000 c001686c GPR08: 00001000 b00045a9 00000001 c 0f58460 c0f50000 00000000 c0007e10 00000000 GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 GPR24: 00000000 00000000 c0ee2550 00000000 c0f57000 00000ff8 00000000 ff800000 PIN [c0017cd4 ] set_pte_at+0xc/0x1e8 LR [c00187f0] map_kernel_page+0x9c/0x100 Seguimiento de llamadas: [e1011e10] [c0736c68] vsnprintf+0x358/0x6c8 (no confiable) [e1011e30] [c0165fec] x44 [e1011e40] [c0c13bdc] early_iounmap +0x11c/0x170 [e1011e70] [c0c06cb0] ioremap_legacy_serial_console+0x88/0xc0 [e1011e90] [c0c03634] do_one_initcall+0x80/0x178 [e1011ef0] [c0c0385c] kernel_init_freeable+0xb4 /0x250 [e1011f20] [c0007e34] kernel_init+0x24/0x140 [e1011f30 ] [c0016268] ret_from_kernel_thread+0x5c/0x64 Volcado de instrucciones: 7fe3fb78 48019689 80010014 7c630034 83e1000c 5463d97e 7c0803a6 38210010 4e800020 0 712a0001 41820008 &lt;0fe00000&gt; 9421ffe0 93e1001c 48000030 Implemente unmap_kernel_page() que borra un pte existente.
References () https://git.kernel.org/stable/c/033fd42c18d9b2121595b6f1e8419a115f9ac5b7 - () https://git.kernel.org/stable/c/033fd42c18d9b2121595b6f1e8419a115f9ac5b7 -
References () https://git.kernel.org/stable/c/43ae0ccc4d2722b833fb59b905af129428e06d03 - () https://git.kernel.org/stable/c/43ae0ccc4d2722b833fb59b905af129428e06d03 -
References () https://git.kernel.org/stable/c/67baac10dd5ad1e9f50e8f2659984b3b0728d54e - () https://git.kernel.org/stable/c/67baac10dd5ad1e9f50e8f2659984b3b0728d54e -
References () https://git.kernel.org/stable/c/aec982603aa8cc0a21143681feb5f60ecc69d718 - () https://git.kernel.org/stable/c/aec982603aa8cc0a21143681feb5f60ecc69d718 -

16 Jul 2024, 12:15

Type Values Removed Values Added
New CVE
Information

Published : 2024-07-16 12:15

Updated : 2025-10-03 14:30

NVD link : CVE-2021-47623

Mitre link : CVE-2021-47623

CVE.ORG link : CVE-2021-47623

JSON object : View

Products Affected

linux

  • linux_kernel
CWE
NVD-CWE-noinfo