CVE-2025-71312: fs/ntfs3: fix ntfs_mount_options leak in ntfs_fill_super()

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-27 · updated 2026-10-26
Weakness: CWE-401

Description

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.

Affected products

Linux kernel: from 6.19 before 6.19.4 — fixed in 6.19.4

How to fix

Upgrade to a fixed version: Linux kernel 6.19.4. Check the vendor advisory for mitigations.

References

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