CVE-2026-43153: Linux内核XFS模块逻辑错误漏洞

/* * Conceptual PoC for CVE-2026-43153 * Demonstrating the problematic return logic leading to UAF */ #include <linux/xfs.h> // Hypothetical structure representation struct xfs_buf { void *data; }; // Simulating the vulnerable function behavior struct xfs_buf *xfs_attr_leaf_hasname_vulnerable(...) { struct xfs_buf *bp; int error; // 1. Read the leaf block error = xfs_attr3_leaf_read(..., &bp); if (error) { return NULL; // Correct: read failed, no buffer } // 2. Internal lookup error = xfs_attr3_leaf_lookup_int(bp, ...); if (error == -ENOATTR || error == -EEXIST) { return bp; // Correct: buffer is valid and needed } // 3. Vulnerability Path: Other errors (e.g., -EFSCORRUPTED) xfs_trans_brelse(NULL, bp); // Buffer is released here // BUG: Returning a pointer to a freed buffer return bp; } /* * Exploitation Logic: * An attacker would trigger an XFS attribute operation (e.g., setxattr) * that forces xfs_attr3_leaf_lookup_int to return an error other than * -ENOATTR or -EEXIST. The caller then receives 'bp', assumes it is valid, * and attempts to access it, leading to a Use-After-Free condition. */