CVE-2022-49408: 
Linux Kernel vulnerability analysis and mitigation

CVE-2022-49408 is a memory leak vulnerability discovered in the Linux kernel's ext4 filesystem component. The issue occurs in the parse_apply_sb_mount_options() function when processing on-disk mount options fails after memory allocation in the ext4_fs_context, specifically affecting s_qf_names. The vulnerability was disclosed on February 26, 2025 (NVD).

The vulnerability stems from improper memory management in the ext4 filesystem code. When processing on-disk mount options fails after memory allocation in the ext4_fs_context structure, the allocated memory (e.g., s_qf_names) is not properly freed. The issue was fixed by replacing direct kfree() calls with ext4_fc_free() to ensure proper cleanup of allocated resources (Kernel Commit).

The vulnerability results in memory leaks in the Linux kernel when mounting ext4 filesystems with specific mount options. This can lead to gradual system memory depletion over time, potentially affecting system stability and performance (Ubuntu Security).

The vulnerability can be triggered by mounting an ext4 filesystem with specific mount options. A proof-of-concept reproducer has been provided that demonstrates the memory leak using mkfs.ext4 and tune2fs commands (Kernel Commit).

The issue has been fixed in the Linux kernel by modifying the cleanup process to use ext4_fc_free() instead of kfree() directly. Users should update their Linux kernel to a patched version. Most major Linux distributions have marked their current releases as not affected by this vulnerability (Ubuntu Security).