Linux Kernel up to 5.14.13 encx24j600 devm_regmap_init_encx24j600 null pointer dereference

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3.5$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 5.14.13. It has been classified as critical. Affected by this vulnerability is the function devm_regmap_init_encx24j600 of the component encx24j600. This manipulation causes null pointer dereference. This vulnerability is tracked as CVE-2021-47440. No exploit exists. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 5.14.13 and classified as critical. Affected by this vulnerability is the function devm_regmap_init_encx24j600 of the component encx24j600. The manipulation with an unknown input leads to a null pointer dereference vulnerability. The CWE definition for the vulnerability is CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. As an impact it is known to affect availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: net: encx24j600: check error in devm_regmap_init_encx24j600 devm_regmap_init may return error which caused by like out of memory, this will results in null pointer dereference later when reading or writing register: general protection fault in encx24j600_spi_probe KASAN: null-ptr-deref in range [0x0000000000000090-0x0000000000000097] CPU: 0 PID: 286 Comm: spi-encx24j600- Not tainted 5.15.0-rc2-00142-g9978db750e31-dirty #11 9c53a778c1306b1b02359f3c2bbedc0222cba652 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 RIP: 0010:regcache_cache_bypass drivers/base/regmap/regcache.c:540 Code: 54 41 89 f4 55 53 48 89 fb 48 83 ec 08 e8 26 94 a8 fe 48 8d bb a0 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 3c 02 00 0f 85 4a 03 00 00 4c 8d ab b0 00 00 00 48 8b ab a0 00 RSP: 0018:ffffc900010476b8 EFLAGS: 00010207 RAX: dffffc0000000000 RBX: fffffffffffffff4 RCX: 0000000000000000 RDX: 0000000000000012 RSI: ffff888002de0000 RDI: 0000000000000094 RBP: ffff888013c9a000 R08: 0000000000000000 R09: fffffbfff3f9cc6a R10: ffffc900010476e8 R11: fffffbfff3f9cc69 R12: 0000000000000001 R13: 000000000000000a R14: ffff888013c9af54 R15: ffff888013c9ad08 FS: 00007ffa984ab580(0000) GS:ffff88801fe00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055a6384136c8 CR3: 000000003bbe6003 CR4: 0000000000770ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: encx24j600_spi_probe drivers/net/ethernet/microchip/encx24j600.c:459 spi_probe drivers/spi/spi.c:397 really_probe drivers/base/dd.c:517 __driver_probe_device drivers/base/dd.c:751 driver_probe_device drivers/base/dd.c:782 __device_attach_driver drivers/base/dd.c:899 bus_for_each_drv drivers/base/bus.c:427 __device_attach drivers/base/dd.c:971 bus_probe_device drivers/base/bus.c:487 device_add drivers/base/core.c:3364 __spi_add_device drivers/spi/spi.c:599 spi_add_device drivers/spi/spi.c:641 spi_new_device drivers/spi/spi.c:717 new_device_store+0x18c/0x1f1 [spi_stub 4e02719357f1ff33f5a43d00630982840568e85e] dev_attr_store drivers/base/core.c:2074 sysfs_kf_write fs/sysfs/file.c:139 kernfs_fop_write_iter fs/kernfs/file.c:300 new_sync_write fs/read_write.c:508 (discriminator 4) vfs_write fs/read_write.c:594 ksys_write fs/read_write.c:648 do_syscall_64 arch/x86/entry/common.c:50 entry_SYSCALL_64_after_hwframe arch/x86/entry/entry_64.S:113 Add error check in devm_regmap_init_encx24j600 to avoid this situation.

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2021-47440 since 05/21/2024. The exploitation appears to be difficult. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 245546 (Linux Distros Unpatched Vulnerability : CVE-2021-47440), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 4.4.290, 4.9.288, 4.14.252, 4.19.213, 5.4.155, 5.10.75 or 5.14.14 eliminates this vulnerability. Applying the patch 66358471fa75/f043fac1133a/fddc7f678d7f/5e5494e6fc8a/4c2eb80fc90b/e19c10d6e07c/322c0e534963/f03dca0c9e22 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.

The vulnerability is also documented in the vulnerability database at Tenable (245546). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.6
VulDB Meta Temp Score: 3.4

VulDB Base Score: 4.8
VulDB Temp Score: 4.6
VulDB Vector: 🔍
VulDB Reliability: 🔍

CNA Base Score: 2.3
CNA Vector: 🔍

CVSSv2info

AVACAuCIA
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 245546
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2021-47440

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Kernel 4.4.290/4.9.288/4.14.252/4.19.213/5.4.155/5.10.75/5.14.14
Patch: 66358471fa75/f043fac1133a/fddc7f678d7f/5e5494e6fc8a/4c2eb80fc90b/e19c10d6e07c/322c0e534963/f03dca0c9e22

Timelineinfo

05/21/2024 🔍
05/22/2024 +1 days 🔍
05/22/2024 +0 days 🔍
08/08/2025 +443 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2021-47440 (🔍)
GCVE (CVE): GCVE-0-2021-47440
GCVE (VulDB): GCVE-100-265837

Entryinfo

Created: 05/22/2024 09:00
Updated: 08/08/2025 18:08
Changes: 05/22/2024 09:00 (58), 11/02/2024 05:45 (13), 08/08/2025 18:08 (2)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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