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CVE-2021-47640— powerpc/kasan: Fix early region not updated correctly

EPSS 0.02% · P5

Affected Version Matrix 15

VendorProductVersion RangeStatus
LinuxLinuxcbd18991e24fea2c31da3bb117c83e4a3538cd11< 7f19245c3647afea8c7c41f795506ef70f64b9f2affected
cbd18991e24fea2c31da3bb117c83e4a3538cd11< f39a3309393a4a484532f6ba745c6acbcfe06115affected
cbd18991e24fea2c31da3bb117c83e4a3538cd11< 5a3d8f3192a409893c57808cc935e16484df1068affected
cbd18991e24fea2c31da3bb117c83e4a3538cd11< de56beace6648065d404cd9835aa7d30e3df519daffected
cbd18991e24fea2c31da3bb117c83e4a3538cd11< e3d157a4b4f4e0268c98be5b7013bf4b31234bb6affected
cbd18991e24fea2c31da3bb117c83e4a3538cd11< dd75080aa8409ce10d50fb58981c6b59bf8707d3affected
3822dd8c102d11ada9d9ed8e04cad0b347a04689affected
5.4affected
… +7 more rows
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I. Basic Information for CVE-2021-47640

Vulnerability Information
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Vulnerability Title
powerpc/kasan: Fix early region not updated correctly
Source: NVD (National Vulnerability Database)
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: powerpc/kasan: Fix early region not updated correctly The shadow's page table is not updated when PTE_RPN_SHIFT is 24 and PAGE_SHIFT is 12. It not only causes false positives but also false negative as shown the following text. Fix it by bringing the logic of kasan_early_shadow_page_entry here. 1. False Positive: ================================================================== BUG: KASAN: vmalloc-out-of-bounds in pcpu_alloc+0x508/0xa50 Write of size 16 at addr f57f3be0 by task swapper/0/1 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.15.0-12267-gdebe436e77c7 #1 Call Trace: [c80d1c20] [c07fe7b8] dump_stack_lvl+0x4c/0x6c (unreliable) [c80d1c40] [c02ff668] print_address_description.constprop.0+0x88/0x300 [c80d1c70] [c02ff45c] kasan_report+0x1ec/0x200 [c80d1cb0] [c0300b20] kasan_check_range+0x160/0x2f0 [c80d1cc0] [c03018a4] memset+0x34/0x90 [c80d1ce0] [c0280108] pcpu_alloc+0x508/0xa50 [c80d1d40] [c02fd7bc] __kmem_cache_create+0xfc/0x570 [c80d1d70] [c0283d64] kmem_cache_create_usercopy+0x274/0x3e0 [c80d1db0] [c2036580] init_sd+0xc4/0x1d0 [c80d1de0] [c00044a0] do_one_initcall+0xc0/0x33c [c80d1eb0] [c2001624] kernel_init_freeable+0x2c8/0x384 [c80d1ef0] [c0004b14] kernel_init+0x24/0x170 [c80d1f10] [c001b26c] ret_from_kernel_thread+0x5c/0x64 Memory state around the buggy address: f57f3a80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f57f3b00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 >f57f3b80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ^ f57f3c00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f57f3c80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ================================================================== 2. False Negative (with KASAN tests): ================================================================== Before fix: ok 45 - kmalloc_double_kzfree # vmalloc_oob: EXPECTATION FAILED at lib/test_kasan.c:1039 KASAN failure expected in "((volatile char *)area)[3100]", but none occurred not ok 46 - vmalloc_oob not ok 1 - kasan ================================================================== After fix: ok 1 - kasan
Source: NVD (National Vulnerability Database)
CVSS Information
N/A
Source: NVD (National Vulnerability Database)
Vulnerability Type
N/A
Source: NVD (National Vulnerability Database)
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，该漏洞源于早期区域未正确更新。
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

VendorProductAffected VersionsCPESubscribe
LinuxLinux cbd18991e24fea2c31da3bb117c83e4a3538cd11 ~ 7f19245c3647afea8c7c41f795506ef70f64b9f2 -
LinuxLinux 5.4 -

II. Public POCs for CVE-2021-47640

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III. Intelligence Information for CVE-2021-47640

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Patch · 6

Same Patch Batch · Linux · 2025-02-26 · 706 CVEs total

CVE-2022-49498ALSA: pcm: Check for null pointer of pointer substream before dereferencing it
CVE-2022-49486ASoC: fsl: Fix refcount leak in imx_sgtl5000_probe
CVE-2022-49488drm/msm/mdp5: Return error code in mdp5_mixer_release when deadlock is detected
CVE-2022-49489drm/msm/disp/dpu1: set vbif hw config to NULL to avoid use after memory free during pm run
CVE-2022-49490drm/msm/mdp5: Return error code in mdp5_pipe_release when deadlock is detected
CVE-2022-49491drm/rockchip: vop: fix possible null-ptr-deref in vop_bind()
CVE-2022-49492nvme-pci: fix a NULL pointer dereference in nvme_alloc_admin_tags
CVE-2022-49493ASoC: rt5645: Fix errorenous cleanup order
CVE-2022-49494mtd: rawnand: cadence: fix possible null-ptr-deref in cadence_nand_dt_probe()
CVE-2022-49495drm/msm/hdmi: check return value after calling platform_get_resource_byname()
CVE-2022-49497net: remove two BUG() from skb_checksum_help()
CVE-2022-49496media: mediatek: vcodec: prevent kernel crash when rmmod mtk-vcodec-dec.ko
CVE-2022-49502media: rga: fix possible memory leak in rga_probe
CVE-2022-49507regulator: da9121: Fix uninit-value in da9121_assign_chip_model()
CVE-2022-49508HID: elan: Fix potential double free in elan_input_configured
CVE-2022-49506drm/mediatek: Add vblank register/unregister callback functions
CVE-2022-49504scsi: lpfc: Inhibit aborts if external loopback plug is inserted
CVE-2022-49505NFC: NULL out the dev->rfkill to prevent UAF
CVE-2022-49501usbnet: Run unregister_netdev() before unbind() again
CVE-2022-49500wl1251: dynamically allocate memory used for DMA

Showing top 20 of 706 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

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