Linux Kernel CVE-2025-71312

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

fs/ntfs3: fix ntfs_mount_options leak in ntfs_fill_super()

In ntfs_fill_super(), the fc->fs_private pointer is set to NULL without first freeing the memory it points to. This causes the subsequent call to ntfs_fs_free() to skip freeing the ntfs_mount_options structure.

This results in a kmemleak report:

unreferenced object 0xff1100015378b800 (size 32): comm "mount", pid 582, jiffies 4294890685 hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 ed ff ed ff 00 04 00 00 ................ backtrace (crc ed541d8c): __kmalloc_cache_noprof+0x424/0x5a0 __ntfs_init_fs_context+0x47/0x590 alloc_fs_context+0x5d8/0x960 __x64_sys_fsopen+0xb1/0x190 do_syscall_64+0x50/0x1f0 entry_SYSCALL_64_after_hwframe+0x76/0x7e

This issue can be reproduced using the following commands: fallocate -l 100M test.file mount test.file /tmp/test

Since sbi->options is duplicated from fc->fs_private and does not directly use the memory allocated for fs_private, it is unnecessary to set fc->fs_private to NULL.

Additionally, this patch simplifies the code by utilizing the helper function put_mount_options() instead of open-coding the cleanup logic.