CVE-2021-47647

Medium

In the Linux kernel, the following vulnerability has been resolved: clk: qcom: ipq8074: fix PCI-E clock oops Fix PCI-E clock related kernel oops that are caused by a missing clock parent. pcie0_rchng_clk_src has num_parents set to 2 but only one parent is actually set via parent_hws, it should also have "XO" defined. This will cause the kernel to panic on a NULL pointer in clk_core_get_parent_by_index(). So, to fix this utilize clk_parent_data to provide gcc_xo_gpll0 parent data. Since there is already an existing static const char * const gcc_xo_gpll0[] used to provide the same parents via parent_names convert those users to clk_parent_data as well. Without this earlycon is needed to even catch the OOPS as it will reset the board before serial is initialized with the following: [ 0.232279] Unable to handle kernel paging request at virtual address 0000a00000000000 [ 0.232322] Mem abort info: [ 0.239094] ESR = 0x96000004 [ 0.241778] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.244908] SET = 0, FnV = 0 [ 0.250377] EA = 0, S1PTW = 0 [ 0.253236] FSC = 0x04: level 0 translation fault [ 0.256277] Data abort info: [ 0.261141] ISV = 0, ISS = 0x00000004 [ 0.264262] CM = 0, WnR = 0 [ 0.267820] [0000a00000000000] address between user and kernel address ranges [ 0.270954] Internal error: Oops: 96000004 [#1] SMP [ 0.278067] Modules linked in: [ 0.282751] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.15.10 #0 [ 0.285882] Hardware name: Xiaomi AX3600 (DT) [ 0.292043] pstate: 20400005 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 0.296299] pc : clk_core_get_parent_by_index+0x68/0xec [ 0.303067] lr : __clk_register+0x1d8/0x820 [ 0.308273] sp : ffffffc01111b7d0 [ 0.312438] x29: ffffffc01111b7d0 x28: 0000000000000000 x27: 0000000000000040 [ 0.315919] x26: 0000000000000002 x25: 0000000000000000 x24: ffffff8000308800 [ 0.323037] x23: ffffff8000308850 x22: ffffff8000308880 x21: ffffff8000308828 [ 0.330155] x20: 0000000000000028 x19: ffffff8000309700 x18: 0000000000000020 [ 0.337272] x17: 000000005cc86990 x16: 0000000000000004 x15: ffffff80001d9d0a [ 0.344391] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000006 [ 0.351508] x11: 0000000000000003 x10: 0101010101010101 x9 : 0000000000000000 [ 0.358626] x8 : 7f7f7f7f7f7f7f7f x7 : 6468626f5e626266 x6 : 17000a3a403c1b06 [ 0.365744] x5 : 061b3c403a0a0017 x4 : 0000000000000000 x3 : 0000000000000001 [ 0.372863] x2 : 0000a00000000000 x1 : 0000000000000001 x0 : ffffff8000309700 [ 0.379982] Call trace: [ 0.387091] clk_core_get_parent_by_index+0x68/0xec [ 0.389351] __clk_register+0x1d8/0x820 [ 0.394210] devm_clk_hw_register+0x5c/0xe0 [ 0.398030] devm_clk_register_regmap+0x44/0x8c [ 0.402198] qcom_cc_really_probe+0x17c/0x1d0 [ 0.406711] qcom_cc_probe+0x34/0x44 [ 0.411224] gcc_ipq8074_probe+0x18/0x30 [ 0.414869] platform_probe+0x68/0xe0 [ 0.418776] really_probe.part.0+0x9c/0x30c [ 0.422336] __driver_probe_device+0x98/0x144 [ 0.426329] driver_probe_device+0x44/0x11c [ 0.430842] __device_attach_driver+0xb4/0x120 [ 0.434836] bus_for_each_drv+0x68/0xb0 [ 0.439349] __device_attach+0xb0/0x170 [ 0.443081] device_initial_probe+0x14/0x20 [ 0.446901] bus_probe_device+0x9c/0xa4 [ 0.451067] device_add+0x35c/0x834 [ 0.454886] of_device_add+0x54/0x64 [ 0.458360] of_platform_device_create_pdata+0xc0/0x100 [ 0.462181] of_platform_bus_create+0x114/0x370 [ 0.467128] of_platform_bus_create+0x15c/0x370 [ 0.471641] of_platform_populate+0x50/0xcc [ 0.476155] of_platform_default_populate_init+0xa8/0xc8 [ 0.480324] do_one_initcall+0x50/0x1b0 [ 0.485877] kernel_init_freeable+0x234/0x29c [ 0.489436] kernel_init+0x24/0x120 [ 0.493948] ret_from_fork+0x10/0x20 [ 0.497253] Code: d50323bf d65f03c0 f94002a2 b4000302 (f9400042) [ 0.501079] ---[ end trace 4ca7e1129da2abce ]---

Package Linux Kernel
Published 2025-02-26
Last modified 2025-09-23
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

5.5

out of 10
Medium
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness type

CWE-476

CVE-2021-47647 is a NULL Pointer Dereference vulnerability

What is NULL Pointer Dereference?

The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. Learn more on MITRE CWE

Affected versions

Linux kernel versions 5.9 and later are affected. Fixed in 5.10.110, 5.15.33, 5.16.19, 5.17.2, 5.18 and their respective stable series.

Affected from
≥ 5.9
Fixed in
✓ 5.10.110 5.10.x ✓ 5.15.33 5.15.x ✓ 5.16.19 5.16.x ✓ 5.17.2 5.17.x ✓ 5.18

References

The following references provide additional information about CVE-2021-47647 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

5 patch commits total View all on NVD

Frequently asked questions

  • What is CVE-2021-47647?

    CVE-2021-47647 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a NULL Pointer Dereference flaw (CWE-476) . It affects Linux kernel versions from 5.9 onward and has been patched in 5.10.110, 5.15.33, 5.16.19 and others. CVE-2021-47647 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2021-47647?

    CVE-2021-47647 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2021-47647?

    Yes — CVE-2021-47647 has been patched. Fixed versions include 5.10.110, 5.15.33, 5.16.19 and others. If you are running Linux kernel 5.9 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2021-47647 actively exploited?

    No — CVE-2021-47647 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

  • What is NULL Pointer Dereference (CWE-476)?

    The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. View CWE-476 on MITRE CWE →

Back to
All CVEs
View on
NVD / NIST