CVE-2021-47440
CVE-2021-47440 is a low-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 2.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-476.
Key facts
- Severity: Low (CVSS 3.x base score 2.3)
- EPSS exploit prediction: 0% (12th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2021-34445
- Weakness: CWE-476
- Affected product: Linux Linux Kernel
- Published:
- Last modified:
Description
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 <80> 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.
Frequently asked questions
- What is CVE-2021-47440?
- 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 <80> 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.
- How severe is CVE-2021-47440?
- CVE-2021-47440 has a CVSS 3.x base score of 2.3, rated low severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
- Is CVE-2021-47440 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (12th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-47440?
- CVE-2021-47440 primarily affects Linux Linux Kernel. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2021-47440?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- Does CVE-2021-47440 have an EU (EUVD) identifier?
- Yes. CVE-2021-47440 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-34445.
- When was CVE-2021-47440 published?
- CVE-2021-47440 was published on 2024-05-22 and last updated on 2026-06-17.
References
- https://git.kernel.org/stable/c/322c0e53496309e634d9db7349678eaad1d25b55
- https://git.kernel.org/stable/c/4c2eb80fc90b05559ce6ed1b8dfb2348420b5644
- https://git.kernel.org/stable/c/5e5494e6fc8a29c927e0478bec4a078a40da8901
- https://git.kernel.org/stable/c/66358471fa75a713fd76bc8a4bd74cb14cd50a4f
- https://git.kernel.org/stable/c/e19c10d6e07c59c96e90fe053a72683ad8b0397e
- https://git.kernel.org/stable/c/f03dca0c9e2297c84a018e306f8a9cd534ee4287
- https://git.kernel.org/stable/c/f043fac1133a6c5ef960a8422c0f6dd711dee462
- https://git.kernel.org/stable/c/fddc7f678d7fb93caa0d7bc512f968ff1e2bddbc
Affected products (6)
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.15:rc3:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.15:rc4:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.15:rc5:*:*:*:*:*:*
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