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CVE-2021-47623— powerpc/fixmap: Fix VM debug warning on unmap

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powerpc/fixmap模块在调用__set_fixmap函数进行fixmap条目取消映射时，存在VM调试警告。

AI Predicted 4.3 Difficulty: Easy EPSS 0.22% · P13

Possible ATT&CK Techniques 1 AI

T1057 · Process Discovery

Affected Version Matrix 10

VendorProduct Version RangeStatus
Linux Linux 265c3491c4bc8d40587996d6ee2f447a7ccfb4f3< 67baac10dd5ad1e9f50e8f2659984b3b0728d54e affected
265c3491c4bc8d40587996d6ee2f447a7ccfb4f3< 43ae0ccc4d2722b833fb59b905af129428e06d03 affected
265c3491c4bc8d40587996d6ee2f447a7ccfb4f3< 033fd42c18d9b2121595b6f1e8419a115f9ac5b7 affected
265c3491c4bc8d40587996d6ee2f447a7ccfb4f3< aec982603aa8cc0a21143681feb5f60ecc69d718 affected
5.5 affected
< 5.5 unaffected
5.10.101≤ 5.10.* unaffected
5.15.24≤ 5.15.* unaffected
… +2 more rows
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I. Basic Information for CVE-2021-47623

Vulnerability Information
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Vulnerability Title
powerpc/fixmap: Fix VM debug warning on unmap
Source: CVE Program / CVE List V5
Vulnerability Description
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.
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powerpc/fixmap模块在调用__set_fixmap函数进行fixmap条目取消映射时，存在VM调试警告。
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

Vendor Product Affected Versions CPE Subscribe
Linux Linux 265c3491c4bc8d40587996d6ee2f447a7ccfb4f3 ~ 67baac10dd5ad1e9f50e8f2659984b3b0728d54e -
Linux Linux 5.5 -

II. Public POCs for CVE-2021-47623

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III. Intelligence Information for CVE-2021-47623

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Other References for CVE-2021-47623 (4)

Same Patch Batch · Linux · 2024-07-16 · 98 CVEs total

CVE-2022-48790 9.8 CRITICAL nvme: fix a possible use-after-free in controller reset during load
CVE-2022-48789 9.8 CRITICAL nvme-tcp: fix possible use-after-free in transport error_recovery work
CVE-2022-48788 9.8 CRITICAL nvme-rdma: fix possible use-after-free in transport error_recovery work
CVE-2022-48851 9.8 CRITICAL staging: gdm724x: fix use after free in gdm_lte_rx()
CVE-2022-48829 9.1 CRITICAL NFSD: Fix NFSv3 SETATTR/CREATE's handling of large file sizes
CVE-2022-48828 9.1 CRITICAL NFSD: Fix ia_size underflow
CVE-2022-48864 8.8 HIGH vdpa/mlx5: add validation for VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET command
CVE-2022-48830 8.8 HIGH can: isotp: fix potential CAN frame reception race in isotp_rcv()
CVE-2022-48782 8.8 HIGH mctp: fix use after free
CVE-2022-48785 8.8 HIGH ipv6: mcast: use rcu-safe version of ipv6_get_lladdr()
CVE-2022-48787 7.8 HIGH iwlwifi: fix use-after-free
CVE-2022-48796 7.8 HIGH iommu: Fix potential use-after-free during probe
CVE-2022-48779 7.8 HIGH net: mscc: ocelot: fix use-after-free in ocelot_vlan_del()
CVE-2022-48821 7.8 HIGH misc: fastrpc: avoid double fput() on failed usercopy
CVE-2022-48822 7.8 HIGH usb: f_fs: Fix use-after-free for epfile
CVE-2022-48847 7.8 HIGH watch_queue: Fix filter limit check
CVE-2022-48786 7.8 HIGH vsock: remove vsock from connected table when connect is interrupted by a signal
CVE-2022-48839 7.8 HIGH net/packet: fix slab-out-of-bounds access in packet_recvmsg()
CVE-2022-48791 7.8 HIGH scsi: pm8001: Fix use-after-free for aborted TMF sas_task
CVE-2022-48792 7.8 HIGH scsi: pm8001: Fix use-after-free for aborted SSP/STP sas_task

Showing top 20 of 98 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2021-47623

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