CVE-2021-47414— riscv: Flush current cpu icache before other cpus
Quick assessment
Affected
Linux Linux
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于riscv模块其他cpu之前刷新当前cpuicache。
Possible ATT&CK Techniques 2 AI
T1055 · Process Injection T1068 · Exploitation for Privilege EscalationAffected Version Matrix 8
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| Linux | Linux | fab957c11efe2f405e08b9f0d080524bc2631428< 427faa29e06f0709476ea1bd59758f997ec8b64e |
affected |
fab957c11efe2f405e08b9f0d080524bc2631428< f1c7aa87c423e765e3862349c2f095fdfccdd9b3 |
affected | ||
fab957c11efe2f405e08b9f0d080524bc2631428< bb8958d5dc79acbd071397abb57b8756375fe1ce |
affected | ||
4.15 |
affected | ||
< 4.15 |
unaffected | ||
5.10.73≤ 5.10.* |
unaffected | ||
5.14.12≤ 5.14.* |
unaffected | ||
5.15≤ * |
unaffected |
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I. Basic Information for CVE-2021-47414
Vulnerability Information
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Vulnerability Title
riscv: Flush current cpu icache before other cpus
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved:
riscv: Flush current cpu icache before other cpus
On SiFive Unmatched, I recently fell onto the following BUG when booting:
[ 0.000000] ftrace: allocating 36610 entries in 144 pages
[ 0.000000] Oops - illegal instruction [#1]
[ 0.000000] Modules linked in:
[ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.13.1+ #5
[ 0.000000] Hardware name: SiFive HiFive Unmatched A00 (DT)
[ 0.000000] epc : riscv_cpuid_to_hartid_mask+0x6/0xae
[ 0.000000] ra : __sbi_rfence_v02+0xc8/0x10a
[ 0.000000] epc : ffffffff80007240 ra : ffffffff80009964 sp : ffffffff81803e10
[ 0.000000] gp : ffffffff81a1ea70 tp : ffffffff8180f500 t0 : ffffffe07fe30000
[ 0.000000] t1 : 0000000000000004 t2 : 0000000000000000 s0 : ffffffff81803e60
[ 0.000000] s1 : 0000000000000000 a0 : ffffffff81a22238 a1 : ffffffff81803e10
[ 0.000000] a2 : 0000000000000000 a3 : 0000000000000000 a4 : 0000000000000000
[ 0.000000] a5 : 0000000000000000 a6 : ffffffff8000989c a7 : 0000000052464e43
[ 0.000000] s2 : ffffffff81a220c8 s3 : 0000000000000000 s4 : 0000000000000000
[ 0.000000] s5 : 0000000000000000 s6 : 0000000200000100 s7 : 0000000000000001
[ 0.000000] s8 : ffffffe07fe04040 s9 : ffffffff81a22c80 s10: 0000000000001000
[ 0.000000] s11: 0000000000000004 t3 : 0000000000000001 t4 : 0000000000000008
[ 0.000000] t5 : ffffffcf04000808 t6 : ffffffe3ffddf188
[ 0.000000] status: 0000000200000100 badaddr: 0000000000000000 cause: 0000000000000002
[ 0.000000] [<ffffffff80007240>] riscv_cpuid_to_hartid_mask+0x6/0xae
[ 0.000000] [<ffffffff80009474>] sbi_remote_fence_i+0x1e/0x26
[ 0.000000] [<ffffffff8000b8f4>] flush_icache_all+0x12/0x1a
[ 0.000000] [<ffffffff8000666c>] patch_text_nosync+0x26/0x32
[ 0.000000] [<ffffffff8000884e>] ftrace_init_nop+0x52/0x8c
[ 0.000000] [<ffffffff800f051e>] ftrace_process_locs.isra.0+0x29c/0x360
[ 0.000000] [<ffffffff80a0e3c6>] ftrace_init+0x80/0x130
[ 0.000000] [<ffffffff80a00f8c>] start_kernel+0x5c4/0x8f6
[ 0.000000] ---[ end trace f67eb9af4d8d492b ]---
[ 0.000000] Kernel panic - not syncing: Attempted to kill the idle task!
[ 0.000000] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]---
While ftrace is looping over a list of addresses to patch, it always failed
when patching the same function: riscv_cpuid_to_hartid_mask. Looking at the
backtrace, the illegal instruction is encountered in this same function.
However, patch_text_nosync, after patching the instructions, calls
flush_icache_range. But looking at what happens in this function:
flush_icache_range -> flush_icache_all
-> sbi_remote_fence_i
-> __sbi_rfence_v02
-> riscv_cpuid_to_hartid_mask
The icache and dcache of the current cpu are never synchronized between the
patching of riscv_cpuid_to_hartid_mask and calling this same function.
So fix this by flushing the current cpu's icache before asking for the other
cpus to do the same.
Source: CVE Program / CVE List V5
CVSS Information
N/A
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Vulnerability Title
Linux kernel 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于riscv模块其他cpu之前刷新当前cpuicache。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
Affected Products
II. Public POCs for CVE-2021-47414
| # | POC Description | Source Link | Shenlong Link |
|---|
AI-Generated POC
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No public POC found.
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Other References for CVE-2021-47414 (3)
Same Patch Batch · Linux · 2024-05-21 · 361 CVEs total
| CVE-2021-47427 | 9.8 CRITICAL | scsi: iscsi: Fix iscsi_task use after free |
| CVE-2021-47328 | 9.8 CRITICAL | scsi: iscsi: Fix conn use after free during resets |
| CVE-2023-52732 | 9.8 CRITICAL | ceph: blocklist the kclient when receiving corrupted snap trace |
| CVE-2023-52741 | 9.8 CRITICAL | cifs: Fix use-after-free in rdata->read_into_pages() |
| CVE-2021-47232 | 9.8 CRITICAL | can: j1939: fix Use-after-Free, hold skb ref while in use |
| CVE-2021-47378 | 9.8 CRITICAL | nvme-rdma: destroy cm id before destroy qp to avoid use after free |
| CVE-2023-52755 | 9.8 CRITICAL | ksmbd: fix slab out of bounds write in smb_inherit_dacl() |
| CVE-2023-52769 | 8.8 HIGH | wifi: ath12k: fix htt mlo-offset event locking |
| CVE-2021-47308 | 8.8 HIGH | scsi: libfc: Fix array index out of bound exception |
| CVE-2023-52801 | 8.8 HIGH | iommufd: Fix missing update of domains_itree after splitting iopt_area |
| CVE-2023-52798 | 8.8 HIGH | wifi: ath11k: fix dfs radar event locking |
| CVE-2023-52846 | 8.8 HIGH | hsr: Prevent use after free in prp_create_tagged_frame() |
| CVE-2023-52790 | 8.8 HIGH | swiotlb: fix out-of-bounds TLB allocations with CONFIG_SWIOTLB_DYNAMIC |
| CVE-2023-52776 | 8.8 HIGH | wifi: ath12k: fix dfs-radar and temperature event locking |
| CVE-2021-47388 | 8.8 HIGH | mac80211: fix use-after-free in CCMP/GCMP RX |
| CVE-2021-47390 | 8.8 HIGH | KVM: x86: Fix stack-out-of-bounds memory access from ioapic_write_indirect() |
| CVE-2021-47352 | 8.4 HIGH | virtio-net: Add validation for used length |
| CVE-2023-52829 | 8.4 HIGH | wifi: ath12k: fix possible out-of-bound write in ath12k_wmi_ext_hal_reg_caps() |
| CVE-2021-47240 | 8.4 HIGH | net: qrtr: fix OOB Read in qrtr_endpoint_post |
| CVE-2021-47244 | 8.2 HIGH | mptcp: Fix out of bounds when parsing TCP options |
Showing top 20 of 361 CVEs. View all on vendor page → →
IV. Related Vulnerabilities
Same product: Linux
-
CVE-2026-98868
dm-pcache: reject a kset that overruns its segment -
CVE-2026-98867
dm-pcache: bound the logical key offset from persistent memo -
CVE-2026-98866
sched/cache: Introduce task_struct->sched_cache_grp to fix U -
CVE-2026-98865
sched_ext: Don't run ops.dequeue() with a DSQ lock held -
CVE-2026-98864
sched_ext: Wait for SCX_OPSS_DISPATCHING before reenqueueing
Same vendor: Linux
-
CVE-2026-98868
dm-pcache: reject a kset that overruns its segment -
CVE-2026-98867
dm-pcache: bound the logical key offset from persistent memo -
CVE-2026-98866
sched/cache: Introduce task_struct->sched_cache_grp to fix U -
CVE-2026-98865
sched_ext: Don't run ops.dequeue() with a DSQ lock held -
CVE-2026-98864
sched_ext: Wait for SCX_OPSS_DISPATCHING before reenqueueing
V. Comments for CVE-2021-47414
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