Buffer over-read vulnerability in Linux Kernel affecting ext4 file system

CVE-2025-40198

What is CVE-2025-40198?

A vulnerability has been identified in the Linux kernel's ext4 file system where a potential buffer over-read can occur in the function parse_apply_sb_mount_options(). This issue arises due to the reliance on tune2fs for proper NUL termination of the s_mount_opts string within the ext4 superblock. The function is now hardened to mitigate risks associated with treating s_mount_opts as a potential __nonstring, enhancing the overall security of the file system.

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