fs: ntfs3: check return value of indx_find to avoid infinite loop

Overview

In the Linux kernel, the following vulnerability has been resolved:

fs: ntfs3: check return value of indx_find to avoid infinite loop

We found an infinite loop bug in the ntfs3 file system that can lead to a Denial-of-Service (DoS) condition.

A malformed dentry in the ntfs3 filesystem can cause the kernel to hang during the lookup operations. By setting the HAS_SUB_NODE flag in an INDEX_ENTRY within a directory's INDEX_ALLOCATION block and manipulating the VCN pointer, an attacker can cause the indx_find() function to repeatedly read the same block, allocating 4 KB of memory each time. The kernel lacks VCN loop detection and depth limits, causing memory exhaustion and an OOM crash.

This patch adds a return value check for fnd_push() to prevent a memory exhaustion vulnerability caused by infinite loops. When the index exceeds the size of the fnd->nodes array, fnd_push() returns -EINVAL. The indx_find() function checks this return value and stops processing, preventing further memory allocation.

Affected

• Linux >= 82cae269cfa953032fbb8980a7d554d60fb00b17 < 14c3188afbedfd5178bbabb8002487ea14b37b56
• Linux >= 82cae269cfa953032fbb8980a7d554d60fb00b17 < 435d34719db0e130f6f0c621d67ed524cc1a7d10
• Linux >= 82cae269cfa953032fbb8980a7d554d60fb00b17 < 68e32694be231c1cdb99b7637a657314e88e1a96
• Linux >= 82cae269cfa953032fbb8980a7d554d60fb00b17 < 398e768d1accd1f5645492ab996005d7aa84a5b0
• Linux >= 82cae269cfa953032fbb8980a7d554d60fb00b17 < b0ea441f44ce64fa514a415d4a9e6e2b06e7946c
• Linux >= 82cae269cfa953032fbb8980a7d554d60fb00b17 < 0ad7a1be44479503dbe5c699759861ef5b8bd70c
• Linux >= 82cae269cfa953032fbb8980a7d554d60fb00b17 < 1732053c8a6b360e2d5afb1b34fe9779398b072c
• Linux 5.15

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.