Linux Kernel up to 6.0.17/6.1.3 /dev/vdb fscrypt_limit_io_blocks null pointer dereference

Summaryinfo

A vulnerability categorized as critical has been discovered in Linux Kernel up to 6.0.17/6.1.3. This affects the function fscrypt_limit_io_blocks of the file /dev/vdb. The manipulation results in null pointer dereference. This vulnerability is cataloged as CVE-2022-50277. There is no exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.0.17/6.1.3. It has been classified as critical. Affected is the function fscrypt_limit_io_blocks of the file /dev/vdb. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as 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. This is going to have an impact on availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: ext4: don't allow journal inode to have encrypt flag Mounting a filesystem whose journal inode has the encrypt flag causes a NULL dereference in fscrypt_limit_io_blocks() when the 'inlinecrypt' mount option is used. The problem is that when jbd2_journal_init_inode() calls bmap(), it eventually finds its way into ext4_iomap_begin(), which calls fscrypt_limit_io_blocks(). fscrypt_limit_io_blocks() requires that if the inode is encrypted, then its encryption key must already be set up. That's not the case here, since the journal inode is never "opened" like a normal file would be. Hence the crash. A reproducer is: mkfs.ext4 -F /dev/vdb debugfs -w /dev/vdb -R "set_inode_field <8> flags 0x80808" mount /dev/vdb /mnt -o inlinecrypt To fix this, make ext4 consider journal inodes with the encrypt flag to be invalid. (Note, maybe other flags should be rejected on the journal inode too. For now, this is just the minimal fix for the above issue.) I've marked this as fixing the commit that introduced the call to fscrypt_limit_io_blocks(), since that's what made an actual crash start being possible. But this fix could be applied to any version of ext4 that supports the encrypt feature.

The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2022-50277 since 09/15/2025. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 265179 (Linux Distros Unpatched Vulnerability : CVE-2022-50277), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.0.18 or 6.1.4 eliminates this vulnerability. Applying the patch 1f7a6626f611aa06d7907aa45b484708dd5ac8bc/bcc5057e1781a3ee889225480d995c3b5cbde555/105c78e12468413e426625831faa7db4284e1fec 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 databases at Tenable (265179) and CERT Bund (WID-SEC-2025-2053). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• IBM QRadar SIEM
• SUSE openSUSE
• Open Source Linux Kernel
• RESF Rocky Linux
• Dell Secure Connect Gateway
• F5 F5OS

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.0.0
• 6.0.1
• 6.0.2
• 6.0.3
• 6.0.4
• 6.0.5
• 6.0.6
• 6.0.7
• 6.0.8
• 6.0.9
• 6.0.10
• 6.0.11
• 6.0.12
• 6.0.13
• 6.0.14
• 6.0.15
• 6.0.16
• 6.0.17
• 6.1.0
• 6.1.1
• 6.1.2
• 6.1.3

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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Entryinfo

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