CVE-2022-50334

MEDIUM EPSS 4.3%
Published Sep 15, 20259mo ago · Modified Jun 17, 20261w ago
5.5 CVSS 3.1
Medium
Find Similar
Published Sep 15, 2025 9mo ago
Last Modified Jun 17, 2026 1w ago

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().

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
4.3% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-476 NULL Pointer Dereference Memory Safety

Affected Products 5

VendorProductVersionRange
linuxlinux_kernel* <5.4.229
linuxlinux_kernel*≥5.5  –  <5.10.163
linuxlinux_kernel*≥5.11  –  <5.15.86
linuxlinux_kernel*≥5.16  –  <6.0.16
linuxlinux_kernel*≥6.1  –  <6.1.2

References 6

  • git.kernel.org https://git.kernel.org/stable/c/26215b7ee923b9251f7bb12c4e5f09dc465d35f2
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/965e8f8ae0f642b5528f5a82b7bcaf15a659d5bd
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/9a8862820cbf1f18dca4f3b4c289d88561b3a384
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/dcd28191be9bbf307ba51a5b485773a55b0037c4
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/f2207145693ae5697a7b59e2add4b92f9e5b0e3c
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/fa71639873518e3587632ae58e25e4a96b57fa90
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/26215b7ee923b9251f7bb12c4e5f09dc465d35f2
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/965e8f8ae0f642b5528f5a82b7bcaf15a659d5bd
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/9a8862820cbf1f18dca4f3b4c289d88561b3a384
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/dcd28191be9bbf307ba51a5b485773a55b0037c4
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/f2207145693ae5697a7b59e2add4b92f9e5b0e3c
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/fa71639873518e3587632ae58e25e4a96b57fa90
    Patch