Buffer Management Issue in Linux Kernel Affecting Btrfs File System

CVE-2025-40235

What is CVE-2025-40235?

A memory access flaw has been identified in the Linux kernel's Btrfs file system. This vulnerability arises from improper handling of partially initialized fs_info structures during the execution of functions like btrfs_check_leaked_roots(). Specifically, if memory allocation for fs_info fails in btrfs_get_tree_subvol(), an incorrect call to free fs_info can lead to dereferencing of a NULL pointer, resulting in a kernel page fault. This issue has been highlighted by syzkaller's reports, outlining the potential for serious operational disruptions when this situation occurs.

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