CVE-2021-47428

CVE Details

Release Date:

2024-05-21

Description

In the Linux kernel, the following vulnerability has been resolved:\npowerpc/64s: fix program check interrupt emergency stack path\nEmergency stack path was jumping into a 3: label inside the\n__GEN_COMMON_BODY macro for the normal path after it had finished,\nrather than jumping over it. By a small miracle this is the correct\nplace to build up a new interrupt frame with the existing stack\npointer, so things basically worked okay with an added weird looking\n700 trap frame on top (which had the wrong ->nip so it didn't decode\nbug messages either).\nFix this by avoiding using numeric labels when jumping over non-trivial\nmacros.\nBefore:\nLE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV\nModules linked in:\nCPU: 0 PID: 88 Comm: sh Not tainted 5.15.0-rc2-00034-ge057cdade6e5 #2637\nNIP: 7265677368657265 LR: c00000000006c0c8 CTR: c0000000000097f0\nREGS: c0000000fffb3a50 TRAP: 0700 Not tainted\nMSR: 9000000000021031 CR: 00000700 XER: 20040000\nCFAR: c0000000000098b0 IRQMASK: 0\nGPR00: c00000000006c964 c0000000fffb3cf0 c000000001513800 0000000000000000\nGPR04: 0000000048ab0778 0000000042000000 0000000000000000 0000000000001299\nGPR08: 000001e447c718ec 0000000022424282 0000000000002710 c00000000006bee8\nGPR12: 9000000000009033 c0000000016b0000 00000000000000b0 0000000000000001\nGPR16: 0000000000000000 0000000000000002 0000000000000000 0000000000000ff8\nGPR20: 0000000000001fff 0000000000000007 0000000000000080 00007fff89d90158\nGPR24: 0000000002000000 0000000002000000 0000000000000255 0000000000000300\nGPR28: c000000001270000 0000000042000000 0000000048ab0778 c000000080647e80\nNIP [7265677368657265] 0x7265677368657265\nLR [c00000000006c0c8] ___do_page_fault+0x3f8/0xb10\nCall Trace:\n[c0000000fffb3cf0] [c00000000000bdac] soft_nmi_common+0x13c/0x1d0 (unreliable)\n--- interrupt: 700 at decrementer_common_virt+0xb8/0x230\nNIP: c0000000000098b8 LR: c00000000006c0c8 CTR: c0000000000097f0\nREGS: c0000000fffb3d60 TRAP: 0700 Not tainted\nMSR: 9000000000021031 CR: 22424282 XER: 20040000\nCFAR: c0000000000098b0 IRQMASK: 0\nGPR00: c00000000006c964 0000000000002400 c000000001513800 0000000000000000\nGPR04: 0000000048ab0778 0000000042000000 0000000000000000 0000000000001299\nGPR08: 000001e447c718ec 0000000022424282 0000000000002710 c00000000006bee8\nGPR12: 9000000000009033 c0000000016b0000 00000000000000b0 0000000000000001\nGPR16: 0000000000000000 0000000000000002 0000000000000000 0000000000000ff8\nGPR20: 0000000000001fff 0000000000000007 0000000000000080 00007fff89d90158\nGPR24: 0000000002000000 0000000002000000 0000000000000255 0000000000000300\nGPR28: c000000001270000 0000000042000000 0000000048ab0778 c000000080647e80\nNIP [c0000000000098b8] decrementer_common_virt+0xb8/0x230\nLR [c00000000006c0c8] ___do_page_fault+0x3f8/0xb10\n--- interrupt: 700\nInstruction dump:\nXXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX\nXXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX\n---[ end trace 6d28218e0cc3c949 ]---\nAfter:\n------------[ cut here ]------------\nkernel BUG at arch/powerpc/kernel/exceptions-64s.S:491!\nOops: Exception in kernel mode, sig: 5 [#1]\nLE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV\nModules linked in:\nCPU: 0 PID: 88 Comm: login Not tainted 5.15.0-rc2-00034-ge057cdade6e5-dirty #2638\nNIP: c0000000000098b8 LR: c00000000006bf04 CTR: c0000000000097f0\nREGS: c0000000fffb3d60 TRAP: 0700 Not tainted\nMSR: 9000000000021031 CR: 24482227 XER: 00040000\nCFAR: c0000000000098b0 IRQMASK: 0\nGPR00: c00000000006bf04 0000000000002400 c000000001513800 c000000001271868\nGPR04: 00000000100f0d29 0000000042000000 0000000000000007 0000000000000009\nGPR08: 00000000100f0d29 0000000024482227 0000000000002710 c000000000181b3c\nGPR12: 9000000000009033 c0000000016b0000 00000000100f0d29 c000000005b22f00\nGPR16: 00000000ffff0000 0000000000000001 0000000000000009 00000000100eed90\nGPR20: 00000000100eed90 00000\n---truncated---

See more information about CVE-2021-47428 from MITRE CVE dictionary and NIST NVD

CVSS Scoring

NOTE: The following CVSS v3.1 metrics and score provided are preliminary and subject to review.

Base Score:	4.4	CVSS Vector:	CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
Attack Vector:	Local network	Attack Complexity:	Low
Privileges Required:	High	User Interaction:	None
Scope:	Unchanged	Confidentiality Impact:	None
Integrity Impact:	None	Availability Impact:	High

Errata information

Platform	Errata	Release Date
Oracle Linux version 9 (kernel)	ELSA-2024-9315	2024-11-14