cve-2026-43071
CRITICAL CVSS 9.1 nvd
Description
In the Linux kernel, the following vulnerability has been resolved: dcache: Limit the minimal number of bucket to two There is an OOB read problem on dentry_hashtable when user sets 'dhash_entries=1': BUG: unable to handle page fault for address: ffff888b30b774b0 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page Oops: Oops: 0000 [#1] SMP PTI RIP: 0010:__d_lookup+0x56/0x120 Call Trace: d_lookup.cold+0x16/0x5d lookup_dcache+0x27/0xf0 lookup_one_qstr_excl+0x2a/0x180 start_dirop+0x55/0xa0 simple_start_creating+0x8d/0xa0 debugfs_start_creating+0x8c/0x180 debugfs_create_dir+0x1d/0x1c0 pinctrl_init+0x6d/0x140 do_one_initcall+0x6d/0x3d0 kernel_init_freeable+0x39f/0x460 kernel_init+0x2a/0x260 There will be only one bucket in dentry_hashtable when dhash_entries is set as one, and d_hash_shift is calculated as 32 by dcache_init(). Then, following process will access more than one buckets(which memory region is not allocated) in dentry_hashtable: d_lookup b = d_hash(hash) dentry_hashtable + ((u32)hashlen >> d_hash_shift) // The C standard defines the behavior of right shift amounts // exceeding the bit width of the operand as undefined. The // result of '(u32)hashlen >> d_hash_shift' becomes 'hashlen', // so 'b' will point to an unallocated memory region. hlist_bl_for_each_entry_rcu(b) hlist_bl_first_rcu(head) h->first // read OOB! Fix it by limiting the minimal number of dentry_hashtable bucket to two, so that 'd_hash_shift' won't exceeds the bit width of type u32.
Timeline
- Published
- 2026-05-05
- Last Modified
- 2026-09-08
CVSS Details
- Attack Vector
- NETWORK
- Attack Complexity
- LOW
- Privileges Required
- NONE
Affected Products
- linux linux_kernel
Weaknesses (CWE)
CVSS metrics
| Version | Base | Severity | Vector | Exploitability | Impact | Source |
|---|---|---|---|---|---|---|
| 3.1 | 9.1 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H |
3.9 | 5.2 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
CPE configurations
OR
| CPE | Version range | Vulnerable |
|---|---|---|
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
>= 3.10.55, < 3.11 | yes |
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
>= 3.12.29, < 3.13 | yes |
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
>= 3.14.19, < 3.15 | yes |
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
>= 3.16.3, < 3.17 | yes |
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
>= 3.17.1, < 6.1.175 | yes |
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
>= 6.2, < 6.6.136 | yes |
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
>= 6.7, < 6.12.83 | yes |
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
>= 6.13, < 6.18.24 | yes |
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
>= 6.19, < 6.19.14 | yes |
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
>= 7.0, < 7.0.1 | yes |
cpe:2.3:o:linux:linux_kernel:3.17:-:*:*:*:*:*:* |
— | yes |
cpe:2.3:o:linux:linux_kernel:3.17:rc5:*:*:*:*:*:* |
— | yes |
cpe:2.3:o:linux:linux_kernel:3.17:rc6:*:*:*:*:*:* |
— | yes |
cpe:2.3:o:linux:linux_kernel:3.17:rc7:*:*:*:*:*:* |
— | yes |
NVD metadata
- NVD status
- Modified
- Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/277cedabb0ab86baae83fa58218be13c6d3e5526 Patch
- https://git.kernel.org/stable/c/426ef05e82ee52c8d0e95fc0808b7383d8352d73 Patch
- https://git.kernel.org/stable/c/45b06bb5ea96f75ad81d7ef446f832ea6b0026fe Patch
- https://git.kernel.org/stable/c/5718df131ab78897a9dd1f2e71c3ba732d4392af Patch
- https://git.kernel.org/stable/c/755b40903eff563768d4d96fd4ef51ec48adde3b Patch
- https://git.kernel.org/stable/c/ddd57ebce245f9c7e2f6902a6c087d6186d2385d Patch
- https://git.kernel.org/stable/c/f08fe8891c3eeb63b73f9f1f6d97aa629c821579 Patch
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
Linked Vulnerabilities
{
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"datePublished": "2026-05-05T16:16:16.420",
"dateUpdated": "2026-09-08T09:18:02.470",
"description": "In the Linux kernel, the following vulnerability has been resolved:\n\ndcache: Limit the minimal number of bucket to two\n\nThere is an OOB read problem on dentry_hashtable when user sets\n'dhash_entries=1':\n BUG: unable to handle page fault for address: ffff888b30b774b0\n #PF: supervisor read access in kernel mode\n #PF: error_code(0x0000) - not-present page\n Oops: Oops: 0000 [#1] SMP PTI\n RIP: 0010:__d_lookup+0x56/0x120\n Call Trace:\n d_lookup.cold+0x16/0x5d\n lookup_dcache+0x27/0xf0\n lookup_one_qstr_excl+0x2a/0x180\n start_dirop+0x55/0xa0\n simple_start_creating+0x8d/0xa0\n debugfs_start_creating+0x8c/0x180\n debugfs_create_dir+0x1d/0x1c0\n pinctrl_init+0x6d/0x140\n do_one_initcall+0x6d/0x3d0\n kernel_init_freeable+0x39f/0x460\n kernel_init+0x2a/0x260\n\nThere will be only one bucket in dentry_hashtable when dhash_entries is\nset as one, and d_hash_shift is calculated as 32 by dcache_init(). Then,\nfollowing process will access more than one buckets(which memory region\nis not allocated) in dentry_hashtable:\n d_lookup\n b = d_hash(hash)\n dentry_hashtable + ((u32)hashlen >> d_hash_shift)\n // The C standard defines the behavior of right shift amounts\n // exceeding the bit width of the operand as undefined. The\n // result of '(u32)hashlen >> d_hash_shift' becomes 'hashlen',\n // so 'b' will point to an unallocated memory region.\n hlist_bl_for_each_entry_rcu(b)\n hlist_bl_first_rcu(head)\n h->first // read OOB!\n\nFix it by limiting the minimal number of dentry_hashtable bucket to two,\nso that 'd_hash_shift' won't exceeds the bit width of type u32.",
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"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndcache: Limit the minimal number of bucket to two\n\nThere is an OOB read problem on dentry_hashtable when user sets\n'dhash_entries=1':\n BUG: unable to handle page fault for address: ffff888b30b774b0\n #PF: supervisor read access in kernel mode\n #PF: error_code(0x0000) - not-present page\n Oops: Oops: 0000 [#1] SMP PTI\n RIP: 0010:__d_lookup+0x56/0x120\n Call Trace:\n d_lookup.cold+0x16/0x5d\n lookup_dcache+0x27/0xf0\n lookup_one_qstr_excl+0x2a/0x180\n start_dirop+0x55/0xa0\n simple_start_creating+0x8d/0xa0\n debugfs_start_creating+0x8c/0x180\n debugfs_create_dir+0x1d/0x1c0\n pinctrl_init+0x6d/0x140\n do_one_initcall+0x6d/0x3d0\n kernel_init_freeable+0x39f/0x460\n kernel_init+0x2a/0x260\n\nThere will be only one bucket in dentry_hashtable when dhash_entries is\nset as one, and d_hash_shift is calculated as 32 by dcache_init(). Then,\nfollowing process will access more than one buckets(which memory region\nis not allocated) in dentry_hashtable:\n d_lookup\n b = d_hash(hash)\n dentry_hashtable + ((u32)hashlen >> d_hash_shift)\n // The C standard defines the behavior of right shift amounts\n // exceeding the bit width of the operand as undefined. The\n // result of '(u32)hashlen >> d_hash_shift' becomes 'hashlen',\n // so 'b' will point to an unallocated memory region.\n hlist_bl_for_each_entry_rcu(b)\n hlist_bl_first_rcu(head)\n h->first // read OOB!\n\nFix it by limiting the minimal number of dentry_hashtable bucket to two,\nso that 'd_hash_shift' won't exceeds the bit width of type u32."
}
],
"evaluatorComment": "\n",
"id": "CVE-2026-43071",
"lastModified": "2026-09-08T09:18:02.470",
"metrics": {
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{
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"attackVector": "NETWORK",
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"baseScore": 9.1,
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"confidentialityImpact": "HIGH",
"integrityImpact": "NONE",
"privilegesRequired": "NONE",
"scope": "UNCHANGED",
"userInteraction": "NONE",
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"source": "nvd",
"title": "In the Linux kernel, the following vulnerability has been resolved:\n\ndcache: Limit the minimal number of bucket to tw..."
}