CVE-2022-50737 in Linux
Summary
by MITRE • 12/24/2025
In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: Validate index root when initialize NTFS security
This enhances the sanity check for $SDH and $SII while initializing NTFS security, guarantees these index root are legit.
[ 162.459513] BUG: KASAN: use-after-free in hdr_find_e.isra.0+0x10c/0x320
[ 162.460176] Read of size 2 at addr ffff8880037bca99 by task mount/243
[ 162.460851]
[ 162.461252] CPU: 0 PID: 243 Comm: mount Not tainted 6.0.0-rc7 #42
[ 162.461744] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[ 162.462609] Call Trace:
[ 162.462954] <TASK>
[ 162.463276] dump_stack_lvl+0x49/0x63
[ 162.463822] print_report.cold+0xf5/0x689
[ 162.464608] ? unwind_get_return_address+0x3a/0x60
[ 162.465766] ? hdr_find_e.isra.0+0x10c/0x320
[ 162.466975] kasan_report+0xa7/0x130
[ 162.467506] ? _raw_spin_lock_irq+0xc0/0xf0
[ 162.467998] ? hdr_find_e.isra.0+0x10c/0x320
[ 162.468536] __asan_load2+0x68/0x90
[ 162.468923] hdr_find_e.isra.0+0x10c/0x320
[ 162.469282] ? cmp_uints+0xe0/0xe0
[ 162.469557] ? cmp_sdh+0x90/0x90
[ 162.469864] ? ni_find_attr+0x214/0x300
[ 162.470217] ? ni_load_mi+0x80/0x80
[ 162.470479] ? entry_SYSCALL_64_after_hwframe+0x63/0xcd
[ 162.470931] ? ntfs_bread_run+0x190/0x190
[ 162.471307] ? indx_get_root+0xe4/0x190
[ 162.471556] ? indx_get_root+0x140/0x190
[ 162.471833] ? indx_init+0x1e0/0x1e0
[ 162.472069] ? fnd_clear+0x115/0x140
[ 162.472363] ? _raw_spin_lock_irqsave+0x100/0x100
[ 162.472731] indx_find+0x184/0x470
[ 162.473461] ? sysvec_apic_timer_interrupt+0x57/0xc0
[ 162.474429] ? indx_find_buffer+0x2d0/0x2d0
[ 162.474704] ? do_syscall_64+0x3b/0x90
[ 162.474962] dir_search_u+0x196/0x2f0
[ 162.475381] ? ntfs_nls_to_utf16+0x450/0x450
[ 162.475661] ? ntfs_security_init+0x3d6/0x440
[ 162.475906] ? is_sd_valid+0x180/0x180
[ 162.476191] ntfs_extend_init+0x13f/0x2c0
[ 162.476496] ? ntfs_fix_post_read+0x130/0x130
[ 162.476861] ? iput.part.0+0x286/0x320
[ 162.477325] ntfs_fill_super+0x11e0/0x1b50
[ 162.477709] ? put_ntfs+0x1d0/0x1d0
[ 162.477970] ? vsprintf+0x20/0x20
[ 162.478258] ? set_blocksize+0x95/0x150
[ 162.478538] get_tree_bdev+0x232/0x370
[ 162.478789] ? put_ntfs+0x1d0/0x1d0
[ 162.479038] ntfs_fs_get_tree+0x15/0x20
[ 162.479374] vfs_get_tree+0x4c/0x130
[ 162.479729] path_mount+0x654/0xfe0
[ 162.480124] ? putname+0x80/0xa0
[ 162.480484] ? finish_automount+0x2e0/0x2e0
[ 162.480894] ? putname+0x80/0xa0
[ 162.481467] ? kmem_cache_free+0x1c4/0x440
[ 162.482280] ? putname+0x80/0xa0
[ 162.482714] do_mount+0xd6/0xf0
[ 162.483264] ? path_mount+0xfe0/0xfe0
[ 162.484782] ? __kasan_check_write+0x14/0x20
[ 162.485593] __x64_sys_mount+0xca/0x110
[ 162.486024] do_syscall_64+0x3b/0x90
[ 162.486543] entry_SYSCALL_64_after_hwframe+0x63/0xcd
[ 162.487141] RIP: 0033:0x7f9d374e948a
[ 162.488324] Code: 48 8b 0d 11 fa 2a 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 008
[ 162.489728] RSP: 002b:00007ffe30e73d18 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
[ 162.490971] RAX: ffffffffffffffda RBX: 0000561cdb43a060 RCX: 00007f9d374e948a
[ 162.491669] RDX: 0000561cdb43a260 RSI: 0000561cdb43a2e0 RDI: 0000561cdb442af0
[ 162.492050] RBP: 0000000000000000 R08: 0000561cdb43a280 R09: 0000000000000020
[ 162.492459] R10: 00000000c0ed0000 R11: 0000000000000206 R12: 0000561cdb442af0
[ 162.493183] R13: 0000561cdb43a260 R14: 0000000000000000 R15: 00000000ffffffff
[ 162.493644] </TASK>
[ 162.493908]
[ 162.494214] The buggy address belongs to the physical page:
[ 162.494761] page:000000003e38a3d5 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x37bc
[ 162.496064] flags: 0xfffffc0000000(node=0|zone=1|lastcpupid=0x1fffff)
[ 162.497278] raw: 000fffffc0000000 ffffea00000df1c8 ffffea00000df008 0000000000000000
[ 162.498928] raw: 0000000000000000 0000000000240000 0
---truncated---
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Analysis
by VulDB Data Team • 04/21/2026
The vulnerability CVE-2022-50737 resides within the Linux kernel's NTFS3 file system driver, specifically in how it handles security initialization during mount operations. This issue manifests as a use-after-free error when processing the $SDH and $SII index roots during NTFS security setup. The flaw occurs during the ntfs_extend_init function, where the kernel attempts to access memory that has already been freed, leading to a kernel memory safety violation. The kernel's memory sanitizer (KASAN) detects this access pattern and triggers a BUG report, indicating that the system is attempting to read from a freed memory location at address ffff8880037bca99. The stack trace reveals the execution path leading to the error, beginning with the mount process and traversing through ntfs_fill_super, ntfs_extend_init, and ultimately to indx_find, which calls hdr_find_e.isra.0, where the invalid memory access is confirmed.
This vulnerability falls under the category of memory safety issues and can be classified as a use-after-free condition, which is commonly associated with CWE-416. The flaw directly impacts the kernel's ability to securely initialize NTFS file systems, particularly when dealing with security descriptors and index structures. The execution path shows that the vulnerability is triggered during file system mounting, where the kernel attempts to validate security data structures. The root cause lies in insufficient validation of index root structures before accessing them, allowing for potential exploitation by malicious actors who could craft specially crafted NTFS file systems to trigger the memory corruption. The vulnerability affects systems that mount NTFS file systems, particularly those using the ntfs3 driver, and could potentially lead to privilege escalation or system instability.
The operational impact of this vulnerability extends beyond simple memory corruption, as it could enable attackers to exploit the kernel's memory management mechanisms to gain unauthorized access or cause system crashes. The use-after-free condition creates a potential attack surface where an attacker could manipulate the file system structure to cause the kernel to access freed memory, potentially leading to code execution or denial of service. The vulnerability is particularly concerning in environments where NTFS file systems are frequently mounted or where automated mounting processes exist, as these scenarios increase the likelihood of exploitation. The ATT&CK framework would categorize this under privilege escalation techniques, specifically leveraging kernel vulnerabilities to gain elevated system privileges. The issue is compounded by the fact that the vulnerability is triggered during normal file system mount operations, making it difficult to detect and mitigate without proper kernel updates.
Mitigation of CVE-2022-50737 requires immediate patching of the Linux kernel to include proper validation of index root structures before memory access. The fix implemented in the kernel addresses the specific validation gap in the ntfs3 driver by ensuring that $SDH and $SII index roots are properly validated during NTFS security initialization. System administrators should update their kernel versions to include the patched ntfs3 driver, particularly those running systems with NTFS file systems or those that mount NTFS volumes automatically. Monitoring for unusual system behavior or kernel memory errors during mount operations can help detect exploitation attempts. Additionally, implementing proper file system access controls and limiting NTFS mount capabilities on systems where such access is not required can reduce the attack surface. The vulnerability demonstrates the critical importance of validating file system metadata structures during kernel operations, as improper validation can lead to memory safety violations that compromise system integrity. Organizations should ensure their kernel versions are up to date with security patches, particularly those addressing memory safety issues in file system drivers, and conduct regular security audits to identify potential vulnerabilities in their kernel configurations.