CVE-2022-50334

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: hugetlbfs: fix null-ptr-deref in hugetlbfs_parse_param() Syzkaller reports a null-ptr-deref bug as follows: ====================================================== KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:hugetlbfs_parse_param+0x1dd/0x8e0 fs/hugetlbfs/inode.c:1380 [...] Call Trace: <TASK> vfs_parse_fs_param fs/fs_context.c:148 [inline] vfs_parse_fs_param+0x1f9/0x3c0 fs/fs_context.c:129 vfs_parse_fs_string+0xdb/0x170 fs/fs_context.c:191 generic_parse_monolithic+0x16f/0x1f0 fs/fs_context.c:231 do_new_mount fs/namespace.c:3036 [inline] path_mount+0x12de/0x1e20 fs/namespace.c:3370 do_mount fs/namespace.c:3383 [inline] __do_sys_mount fs/namespace.c:3591 [inline] __se_sys_mount fs/namespace.c:3568 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3568 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd [...] </TASK> ====================================================== According to commit "vfs: parse: deal with zero length string value", kernel will set the param->string to null pointer in vfs_parse_fs_string() if fs string has zero length. Yet the problem is that, hugetlbfs_parse_param() will dereference the param->string, without checking whether it is a null pointer. To be more specific, if hugetlbfs_parse_param() parses an illegal mount parameter, such as "size=,", kernel will constructs struct fs_parameter with null pointer in vfs_parse_fs_string(), then passes this struct fs_parameter to hugetlbfs_parse_param(), which triggers the above null-ptr-deref bug. This patch solves it by adding sanity check on param->string in hugetlbfs_parse_param().

Severity

MEDIUM

CVSS score

5.5 (v3.1)

Vulnerability status

Analyzed

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2025-09-15 15:15:45.677000

Last modified

2026-11-05 20:17:35.590000

View original CVE JSON

{
  "id": "CVE-2022-50334",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2025-09-15T15:15:45.677",
  "lastModified": "2026-11-05T20:17:35.590",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nhugetlbfs: fix null-ptr-deref in hugetlbfs_parse_param()\n\nSyzkaller reports a null-ptr-deref bug as follows:\n======================================================\nKASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]\nRIP: 0010:hugetlbfs_parse_param+0x1dd/0x8e0 fs/hugetlbfs/inode.c:1380\n[...]\nCall Trace:\n <TASK>\n vfs_parse_fs_param fs/fs_context.c:148 [inline]\n vfs_parse_fs_param+0x1f9/0x3c0 fs/fs_context.c:129\n vfs_parse_fs_string+0xdb/0x170 fs/fs_context.c:191\n generic_parse_monolithic+0x16f/0x1f0 fs/fs_context.c:231\n do_new_mount fs/namespace.c:3036 [inline]\n path_mount+0x12de/0x1e20 fs/namespace.c:3370\n do_mount fs/namespace.c:3383 [inline]\n __do_sys_mount fs/namespace.c:3591 [inline]\n __se_sys_mount fs/namespace.c:3568 [inline]\n __x64_sys_mount+0x27f/0x300 fs/namespace.c:3568\n do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80\n entry_SYSCALL_64_after_hwframe+0x63/0xcd\n [...]\n </TASK>\n======================================================\n\nAccording to commit \"vfs: parse: deal with zero length string value\",\nkernel will set the param->string to null pointer in vfs_parse_fs_string()\nif fs string has zero length.\n\nYet the problem is that, hugetlbfs_parse_param() will dereference the\nparam->string, without checking whether it is a null pointer.  To be more\nspecific, if hugetlbfs_parse_param() parses an illegal mount parameter,\nsuch as \"size=,\", kernel will constructs struct fs_parameter with null\npointer in vfs_parse_fs_string(), then passes this struct fs_parameter to\nhugetlbfs_parse_param(), which triggers the above null-ptr-deref bug.\n\nThis patch solves it by adding sanity check on param->string\nin hugetlbfs_parse_param()."
    }
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              "versionType": "original_commit_for_fix",
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  "metrics": {
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        "source": "[email protected]",
        "type": "Primary",
        "cvssData": {
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          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
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        "exploitabilityScore": 1.8,
        "impactScore": 3.6
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    "ssvcV203": [
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          "role": "CISA Coordinator",
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  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
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          "value": "CWE-476"
        }
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