CVE-2021-47055: mtd: require write permissions for locking and badblock ioctls
In the Linux kernel, the following vulnerability has been resolved:
mtd: require write permissions for locking and badblock ioctls
MEMLOCK, MEMUNLOCK and OTPLOCK modify protection bits. Thus require write permission. Depending on the hardware MEMLOCK might even be write-once, e.g. for SPI-NOR flashes with their WP# tied to GND. OTPLOCK is always write-once.
MEMSETBADBLOCK modifies the bad block table.
Other sources
In the Linux kernel, the following vulnerability has been resolved:
mtd: require write permissions for locking and badblock ioctls
The Linux kernel CVE team has assigned CVE-2021-47055 to this issue.
Upstream advisory: https://lore.kernel.org/linux-cve-announce/2024022950-CVE-2021-47055-6927@gregkh/T/#u
— Red Hat
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 5.10.223-1Fixed in 5.10.234-1Fixed in 6.1.129-1Fixed in 6.1.133-1Fixed in 6.12.22-1Fixed in 6.12.25-1 - Upgrade
Upgrade
redhat/kernelto a version that resolves this vulnerability.Fixed in 4.4.269 - Upgrade
Upgrade
redhat/kernelto a version that resolves this vulnerability.Fixed in 4.9.269 - Upgrade
Upgrade
redhat/kernelto a version that resolves this vulnerability.Fixed in 4.14.233 - Upgrade
Upgrade
redhat/kernelto a version that resolves this vulnerability.Fixed in 4.19.191 - Upgrade
Upgrade
redhat/kernelto a version that resolves this vulnerability.Fixed in 5.4.119 - Upgrade
Upgrade
redhat/kernelto a version that resolves this vulnerability.Fixed in 5.10.37 - Upgrade
Upgrade
redhat/kernelto a version that resolves this vulnerability.Fixed in 5.11.21 - Upgrade
Upgrade
redhat/kernelto a version that resolves this vulnerability.Fixed in 5.12.4 - Upgrade
Upgrade
redhat/kernelto a version that resolves this vulnerability.Fixed in 5.13 - Configuration
Update the Linux kernel mtd code/behavior so that ioctls that modify protection bits (MEMLOCK, MEMUNLOCK, OTPLOCK) and the bad block table (MEMSETBADBLOCK) require write permission; OTPLOCK is always write-once.
Linux kernel mtd (MEMLOCK/MEMUNLOCK/OTPLOCK; MEMSETBADBLOCK) Enforce write permissions = Require write permission for locking and badblock ioctls (MEMLOCK, MEMUNLOCK, OTPLOCK; and MEMSETBADBLOCK)
Event History
Frequently Asked Questions
What is the severity of CVE-2021-47055?
CVE-2021-47055 has a medium severity due to improper permission checks in the Linux kernel.
How do I fix CVE-2021-47055?
To fix CVE-2021-47055, you should update your Linux kernel to the specified patched versions such as 4.4.269, 4.9.269, 4.14.233, or others listed in the advisory.
Which Linux kernel versions are affected by CVE-2021-47055?
CVE-2021-47055 affects multiple Linux kernel versions prior to the patched versions including 4.4.269, 4.9.269, 4.14.233, and later.
Is CVE-2021-47055 specific to any distribution of Linux?
CVE-2021-47055 is applicable to various distributions of Linux that use the affected kernel versions such as Red Hat and Debian.
What are the consequences of not addressing CVE-2021-47055?
Failing to address CVE-2021-47055 may lead to unauthorized write access to critical parts of the memory, compromising system integrity.