CVE Catalog

CVE-2026-80806

Unknown
Published: Translated: NVD NIST

Summary

In the Linux kernel, the ext4 filesystem may enable DAX on new encrypted files, causing data written to the file to bypass encryption. This occurs because the EXT4_INODE_ENCRYPT flag is set too late.

Risk Assessment

Data confidentiality may be compromised as data written to the file is not encrypted, potentially leading to exposure of sensitive information.

Recommendation

Apply a Linux kernel update that includes the fix setting EXT4_INODE_ENCRYPT earlier to prevent enabling DAX on new encrypted files.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: ext4: don't enable DAX on new encrypted files Currently, when a new encrypted regular file is created, the call to ext4_set_inode_flags(inode, init=true) in __ext4_new_inode() is made before EXT4_INODE_ENCRYPT is set. As a result, it can set S_DAX if the filesystem is mounted with "-o dax=always". EXT4_INODE_ENCRYPT then actually gets set a bit later in __ext4_new_inode(), when it calls fscrypt_set_context() which calls ext4_set_context(). ext4_set_context() sets EXT4_INODE_ENCRYPT and calls ext4_set_inode_flags(inode, init=false) to set S_ENCRYPTED too. This was intended to clear S_DAX as well. However, this was broken by commit 043546e46dc7 ("fs/ext4: Only change S_DAX on inode load"). This causes data written to the file to bypass encryption, also causing xfstests failures such as generic/548 (when "-o dax=always" is used). Fix this by simplifying the flow by making __ext4_new_inode() set EXT4_INODE_ENCRYPT earlier. This makes it take effect in ext4_set_inode_flags(inode, init=true), making S_DAX never be set. Similarly, make EXT4_STATE_MAY_INLINE_DATA never be set in the first place on new encrypted inodes. Then it doesn't need to be cleared. As a result of these simplifications, ext4_set_context() no longer needs to change inode flags or state when 'handle != NULL'. Remove that too.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS