Linux Kernel up to 5.10.72/5.14.11 stack-based overflow

Summaryinfo

A vulnerability identified as critical has been detected in Linux Kernel up to 5.10.72/5.14.11. The affected element is an unknown function. Performing a manipulation results in stack-based overflow. This vulnerability is identified as CVE-2021-47428. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability classified as critical has been found in Linux Kernel up to 5.10.72/5.14.11. This affects some unknown functionality. The manipulation with an unknown input leads to a stack-based overflow vulnerability. CWE is classifying the issue as CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: powerpc/64s: fix program check interrupt emergency stack path Emergency stack path was jumping into a 3: label inside the __GEN_COMMON_BODY macro for the normal path after it had finished, rather than jumping over it. By a small miracle this is the correct place to build up a new interrupt frame with the existing stack pointer, so things basically worked okay with an added weird looking 700 trap frame on top (which had the wrong ->nip so it didn't decode bug messages either). Fix this by avoiding using numeric labels when jumping over non-trivial macros. Before: LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV Modules linked in: CPU: 0 PID: 88 Comm: sh Not tainted 5.15.0-rc2-00034-ge057cdade6e5 #2637 NIP: 7265677368657265 LR: c00000000006c0c8 CTR: c0000000000097f0 REGS: c0000000fffb3a50 TRAP: 0700 Not tainted MSR: 9000000000021031 CR: 00000700 XER: 20040000 CFAR: c0000000000098b0 IRQMASK: 0 GPR00: c00000000006c964 c0000000fffb3cf0 c000000001513800 0000000000000000 GPR04: 0000000048ab0778 0000000042000000 0000000000000000 0000000000001299 GPR08: 000001e447c718ec 0000000022424282 0000000000002710 c00000000006bee8 GPR12: 9000000000009033 c0000000016b0000 00000000000000b0 0000000000000001 GPR16: 0000000000000000 0000000000000002 0000000000000000 0000000000000ff8 GPR20: 0000000000001fff 0000000000000007 0000000000000080 00007fff89d90158 GPR24: 0000000002000000 0000000002000000 0000000000000255 0000000000000300 GPR28: c000000001270000 0000000042000000 0000000048ab0778 c000000080647e80 NIP [7265677368657265] 0x7265677368657265 LR [c00000000006c0c8] ___do_page_fault+0x3f8/0xb10 Call Trace: [c0000000fffb3cf0] [c00000000000bdac] soft_nmi_common+0x13c/0x1d0 (unreliable) --- interrupt: 700 at decrementer_common_virt+0xb8/0x230 NIP: c0000000000098b8 LR: c00000000006c0c8 CTR: c0000000000097f0 REGS: c0000000fffb3d60 TRAP: 0700 Not tainted MSR: 9000000000021031 CR: 22424282 XER: 20040000 CFAR: c0000000000098b0 IRQMASK: 0 GPR00: c00000000006c964 0000000000002400 c000000001513800 0000000000000000 GPR04: 0000000048ab0778 0000000042000000 0000000000000000 0000000000001299 GPR08: 000001e447c718ec 0000000022424282 0000000000002710 c00000000006bee8 GPR12: 9000000000009033 c0000000016b0000 00000000000000b0 0000000000000001 GPR16: 0000000000000000 0000000000000002 0000000000000000 0000000000000ff8 GPR20: 0000000000001fff 0000000000000007 0000000000000080 00007fff89d90158 GPR24: 0000000002000000 0000000002000000 0000000000000255 0000000000000300 GPR28: c000000001270000 0000000042000000 0000000048ab0778 c000000080647e80 NIP [c0000000000098b8] decrementer_common_virt+0xb8/0x230 LR [c00000000006c0c8] ___do_page_fault+0x3f8/0xb10 --- interrupt: 700 Instruction dump: XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX ---[ end trace 6d28218e0cc3c949 ]--- After: ------------[ cut here ]------------ kernel BUG at arch/powerpc/kernel/exceptions-64s.S:491! Oops: Exception in kernel mode, sig: 5 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV Modules linked in: CPU: 0 PID: 88 Comm: login Not tainted 5.15.0-rc2-00034-ge057cdade6e5-dirty #2638 NIP: c0000000000098b8 LR: c00000000006bf04 CTR: c0000000000097f0 REGS: c0000000fffb3d60 TRAP: 0700 Not tainted MSR: 9000000000021031 CR: 24482227 XER: 00040000 CFAR: c0000000000098b0 IRQMASK: 0 GPR00: c00000000006bf04 0000000000002400 c000000001513800 c000000001271868 GPR04: 00000000100f0d29 0000000042000000 0000000000000007 0000000000000009 GPR08: 00000000100f0d29 0000000024482227 0000000000002710 c000000000181b3c GPR12: 9000000000009033 c0000000016b0000 00000000100f0d29 c000000005b22f00 GPR16: 00000000ffff0000 0000000000000001 0000000000000009 00000000100eed90 GPR20: 00000000100eed90 00000 ---truncated---

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2021-47428 since 05/21/2024. The exploitability is told to be easy. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/25/2025).

Upgrading to version 5.10.73 or 5.14.12 eliminates this vulnerability. Applying the patch 411b38fe68ba/c835b3d1d636/3e607dc4df18 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.10.0
• 5.10.1
• 5.10.2
• 5.10.3
• 5.10.4
• 5.10.5
• 5.10.6
• 5.10.7
• 5.10.8
• 5.10.9
• 5.10.10
• 5.10.11
• 5.10.12
• 5.10.13
• 5.10.14
• 5.10.15
• 5.10.16
• 5.10.17
• 5.10.18
• 5.10.19
• 5.10.20
• 5.10.21
• 5.10.22
• 5.10.23
• 5.10.24
• 5.10.25
• 5.10.26
• 5.10.27
• 5.10.28
• 5.10.29
• 5.10.30
• 5.10.31
• 5.10.32
• 5.10.33
• 5.10.34
• 5.10.35
• 5.10.36
• 5.10.37
• 5.10.38
• 5.10.39
• 5.10.40
• 5.10.41
• 5.10.42
• 5.10.43
• 5.10.44
• 5.10.45
• 5.10.46
• 5.10.47
• 5.10.48
• 5.10.49
• 5.10.50
• 5.10.51
• 5.10.52
• 5.10.53
• 5.10.54
• 5.10.55
• 5.10.56
• 5.10.57
• 5.10.58
• 5.10.59
• 5.10.60
• 5.10.61
• 5.10.62
• 5.10.63
• 5.10.64
• 5.10.65
• 5.10.66
• 5.10.67
• 5.10.68
• 5.10.69
• 5.10.70
• 5.10.71
• 5.10.72
• 5.14.0
• 5.14.1
• 5.14.2
• 5.14.3
• 5.14.4
• 5.14.5
• 5.14.6
• 5.14.7
• 5.14.8
• 5.14.9
• 5.14.10
• 5.14.11

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

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Sourcesinfo

Entryinfo

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