fkie_cve-2025-39817
Vulnerability from fkie_nvd
Published
2025-09-16 13:15
Modified
2025-09-18 13:43
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: efivarfs: Fix slab-out-of-bounds in efivarfs_d_compare Observed on kernel 6.6 (present on master as well): BUG: KASAN: slab-out-of-bounds in memcmp+0x98/0xd0 Call trace: kasan_check_range+0xe8/0x190 __asan_loadN+0x1c/0x28 memcmp+0x98/0xd0 efivarfs_d_compare+0x68/0xd8 __d_lookup_rcu_op_compare+0x178/0x218 __d_lookup_rcu+0x1f8/0x228 d_alloc_parallel+0x150/0x648 lookup_open.isra.0+0x5f0/0x8d0 open_last_lookups+0x264/0x828 path_openat+0x130/0x3f8 do_filp_open+0x114/0x248 do_sys_openat2+0x340/0x3c0 __arm64_sys_openat+0x120/0x1a0 If dentry->d_name.len < EFI_VARIABLE_GUID_LEN , 'guid' can become negative, leadings to oob. The issue can be triggered by parallel lookups using invalid filename: T1 T2 lookup_open ->lookup simple_lookup d_add // invalid dentry is added to hash list lookup_open d_alloc_parallel __d_lookup_rcu __d_lookup_rcu_op_compare hlist_bl_for_each_entry_rcu // invalid dentry can be retrieved ->d_compare efivarfs_d_compare // oob Fix it by checking 'guid' before cmp.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/0f63fbabeaaaaaaf5b742a2f4c1b4590d50bf1f6
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/568e7761279b99c6daa3002290fd6d8047ddb6d2
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/71581a82f38e5a4d807d71fc1bb59aead80ccf95
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/794399019301944fd6d2e0d7a51b3327e26c410e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/925599eba46045930b850a98ae594d2e3028ac40
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a6358f8cf64850f3f27857b8ed8c1b08cfc4685c
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c2925cd6207079c3f4d040d082515db78d63afbf
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d7f5e35e70507d10cbaff5f9e194ed54c4ee14f7
Impacted products
Vendor Product Version


To clipboard 

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nefivarfs: Fix slab-out-of-bounds in efivarfs_d_compare\n\nObserved on kernel 6.6 (present on master as well):\n\n  BUG: KASAN: slab-out-of-bounds in memcmp+0x98/0xd0\n  Call trace:\n   kasan_check_range+0xe8/0x190\n   __asan_loadN+0x1c/0x28\n   memcmp+0x98/0xd0\n   efivarfs_d_compare+0x68/0xd8\n   __d_lookup_rcu_op_compare+0x178/0x218\n   __d_lookup_rcu+0x1f8/0x228\n   d_alloc_parallel+0x150/0x648\n   lookup_open.isra.0+0x5f0/0x8d0\n   open_last_lookups+0x264/0x828\n   path_openat+0x130/0x3f8\n   do_filp_open+0x114/0x248\n   do_sys_openat2+0x340/0x3c0\n   __arm64_sys_openat+0x120/0x1a0\n\nIf dentry-\u003ed_name.len \u003c EFI_VARIABLE_GUID_LEN , \u0027guid\u0027 can become\nnegative, leadings to oob. The issue can be triggered by parallel\nlookups using invalid filename:\n\n  T1\t\t\tT2\n  lookup_open\n   -\u003elookup\n    simple_lookup\n     d_add\n     // invalid dentry is added to hash list\n\n\t\t\tlookup_open\n\t\t\t d_alloc_parallel\n\t\t\t  __d_lookup_rcu\n\t\t\t   __d_lookup_rcu_op_compare\n\t\t\t    hlist_bl_for_each_entry_rcu\n\t\t\t    // invalid dentry can be retrieved\n\t\t\t     -\u003ed_compare\n\t\t\t      efivarfs_d_compare\n\t\t\t      // oob\n\nFix it by checking \u0027guid\u0027 before cmp."
    }
  ],
  "id": "CVE-2025-39817",
  "lastModified": "2025-09-18T13:43:34.310",
  "metrics": {},
  "published": "2025-09-16T13:15:57.187",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0f63fbabeaaaaaaf5b742a2f4c1b4590d50bf1f6"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/568e7761279b99c6daa3002290fd6d8047ddb6d2"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/71581a82f38e5a4d807d71fc1bb59aead80ccf95"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/794399019301944fd6d2e0d7a51b3327e26c410e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/925599eba46045930b850a98ae594d2e3028ac40"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a6358f8cf64850f3f27857b8ed8c1b08cfc4685c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c2925cd6207079c3f4d040d082515db78d63afbf"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d7f5e35e70507d10cbaff5f9e194ed54c4ee14f7"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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