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CVE-2025-40052

Estado: AplazadaSin puntuar—

In the Linux kernel, the following vulnerability has been resolved:

smb: client: fix crypto buffers in non-linear memory

The crypto API, through the scatterlist API, expects input buffers to be in linear memory. We handle this with the cifs_sg_set_buf() helper that converts vmalloc'd memory to their corresponding pages.

However, when we allocate our aead_request buffer (@creq in smb2ops.c::crypt_message()), we do so with kvzalloc(), which possibly puts aead_request->__ctx in vmalloc area.

AEAD algorithm then uses ->__ctx for its private/internal data and operations, and uses sg_set_buf() for such data on a few places.

Leer descripción completaMostrar menos

This works fine as long as @creq falls into kmalloc zone (small requests) or vmalloc'd memory is still within linear range.

Tasks' stacks are vmalloc'd by default (CONFIG_VMAP_STACK=y), so too many tasks will increment the base stacks' addresses to a point where virt_addr_valid(buf) will fail (BUG() in sg_set_buf()) when that happens.

In practice: too many parallel reads and writes on an encrypted mount will trigger this bug.

To fix this, always alloc @creq with kmalloc() instead. Also drop the @sensitive_size variable/arguments since kfree_sensitive() doesn't need it.

Backtrace:

Detalles técnicos trazas, registros y código del informe original
[  945.272081] ------------[ cut here ]------------
[  945.272774] kernel BUG at include/linux/scatterlist.h:209!
[  945.273520] Oops: invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC NOPTI
[  945.274412] CPU: 7 UID: 0 PID: 56 Comm: kworker/u33:0 Kdump: loaded Not tainted 6.15.0-lku-11779-g8e9d6efccdd7-dirty #1 PREEMPT(voluntary)
[  945.275736] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-2-gc13ff2cd-prebuilt.qemu.org 04/01/2014
[  945.276877] Workqueue: writeback wb_workfn (flush-cifs-2)
[  945.277457] RIP: 0010:crypto_gcm_init_common+0x1f9/0x220
[  945.278018] Code: b0 00 00 00 48 83 c4 08 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 48 c7 c0 00 00 00 80 48 2b 05 5c 58 e5 00 e9 58 ff ff ff <0f> 0b 0f 0b 0f 0b 0f 0b 0f 0b 0f 0b 48 c7 04 24 01 00 00 00 48 8b
[  945.279992] RSP: 0018:ffffc90000a27360 EFLAGS: 00010246
[  945.280578] RAX: 0000000000000000 RBX: ffffc90001d85060 RCX: 0000000000000030
[  945.281376] RDX: 0000000000080000 RSI: 0000000000000000 RDI: ffffc90081d85070
[  945.282145] RBP: ffffc90001d85010 R08: ffffc90001d85000 R09: 0000000000000000
[  945.282898] R10: ffffc90001d85090 R11: 0000000000001000 R12: ffffc90001d85070
[  945.283656] R13: ffff888113522948 R14: ffffc90001d85060 R15: ffffc90001d85010
[  945.284407] FS:  0000000000000000(0000) GS:ffff8882e66cf000(0000) knlGS:0000000000000000
[  945.285262] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  945.285884] CR2: 00007fa7ffdd31f4 CR3: 000000010540d000 CR4: 0000000000350ef0
[  945.286683] Call Trace:
[  945.286952]  <TASK>
[  945.287184]  ? crypt_message+0x33f/0xad0 [cifs]
[  945.287719]  crypto_gcm_encrypt+0x36/0xe0
[  945.288152]  crypt_message+0x54a/0xad0 [cifs]
[  945.288724]  smb3_init_transform_rq+0x277/0x300 [cifs]
[  945.289300]  smb_send_rqst+0xa3/0x160 [cifs]
[  945.289944]  cifs_call_async+0x178/0x340 [cifs]
[  945.290514]  ? __pfx_smb2_writev_callback+0x10/0x10 [cifs]
[  945.291177]  smb2_async_writev+0x3e3/0x670 [cifs]
[  945.291759]  ? find_held_lock+0x32/0x90
[  945.292212]  ? netfs_advance_write+0xf2/0x310
[  945.292723]  netfs_advance_write+0xf2/0x310
[  945.293210]  netfs_write_folio+0x346/0xcc0
[  945.293689]  ? __pfx__raw_spin_unlock_irq+0x10/0x10
[  945.294250]  netfs_writepages+0x117/0x460
[  945.294724]  do_writepages+0xbe/0x170
[  945.295152]  ? find_held_lock+0x32/0x90
[  945.295600]  ? kvm_sched_clock_read+0x11/0x20
[  945.296103]  __writeback_single_inode+0x56/0x4b0
[  945.296643]  writeback_sb_inodes+0x229/0x550
[  945.297140]  __writeback_inodes_wb+0x4c/0xe0
[  945.297642]  wb_writeback+0x2f1/0x3f0
[  945.298069]  wb_workfn+0x300/0x490
[  945.298472]  process_one_work+0x1fe/0x590
[  945.298949]  worker_thread+0x1ce/0x3c0
[  945.299397]  ? __pfx_worker_thread+0x10/0x10
[  945.299900]  kthr
---truncated---

CVSS

NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

Tecnologías afectadas (1)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2025-40052",
  "cveTags": [],
  "metrics": {},
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "d08089f649a0cfb2099c8551ac47eef0cc23fdf2",
              "lessThan": "ba905a567105dde21cdb8e6d3a87110fa434b393",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "d08089f649a0cfb2099c8551ac47eef0cc23fdf2",
              "lessThan": "7a8a8c15468f0c99685e9964451feffd1a3cc859",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "d08089f649a0cfb2099c8551ac47eef0cc23fdf2",
              "lessThan": "4a61b68abd2788db0364c9a0b6a39f1699fea440",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "d08089f649a0cfb2099c8551ac47eef0cc23fdf2",
              "lessThan": "998a67b954680f26f3734040aeeed08642d49721",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "fs/smb/client/smb2ops.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.3"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.3",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.6.112",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "status": "unaffected",
              "version": "6.12.53",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.17.3",
              "versionType": "semver",
              "lessThanOrEqual": "6.17.*"
            },
            {
              "status": "unaffected",
              "version": "6.18",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "fs/smb/client/smb2ops.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2025-10-28T12:15:39.383",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/4a61b68abd2788db0364c9a0b6a39f1699fea440",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/7a8a8c15468f0c99685e9964451feffd1a3cc859",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/998a67b954680f26f3734040aeeed08642d49721",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/ba905a567105dde21cdb8e6d3a87110fa434b393",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Deferred",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix crypto buffers in non-linear memory\n\nThe crypto API, through the scatterlist API, expects input buffers to be\nin linear memory.  We handle this with the cifs_sg_set_buf() helper\nthat converts vmalloc'd memory to their corresponding pages.\n\nHowever, when we allocate our aead_request buffer (@creq in\nsmb2ops.c::crypt_message()), we do so with kvzalloc(), which possibly\nputs aead_request->__ctx in vmalloc area.\n\nAEAD algorithm then uses ->__ctx for its private/internal data and\noperations, and uses sg_set_buf() for such data on a few places.\n\nThis works fine as long as @creq falls into kmalloc zone (small\nrequests) or vmalloc'd memory is still within linear range.\n\nTasks' stacks are vmalloc'd by default (CONFIG_VMAP_STACK=y), so too\nmany tasks will increment the base stacks' addresses to a point where\nvirt_addr_valid(buf) will fail (BUG() in sg_set_buf()) when that\nhappens.\n\nIn practice: too many parallel reads and writes on an encrypted mount\nwill trigger this bug.\n\nTo fix this, always alloc @creq with kmalloc() instead.\nAlso drop the @sensitive_size variable/arguments since\nkfree_sensitive() doesn't need it.\n\nBacktrace:\n\n[  945.272081] ------------[ cut here ]------------\n[  945.272774] kernel BUG at include/linux/scatterlist.h:209!\n[  945.273520] Oops: invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC NOPTI\n[  945.274412] CPU: 7 UID: 0 PID: 56 Comm: kworker/u33:0 Kdump: loaded Not tainted 6.15.0-lku-11779-g8e9d6efccdd7-dirty #1 PREEMPT(voluntary)\n[  945.275736] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-2-gc13ff2cd-prebuilt.qemu.org 04/01/2014\n[  945.276877] Workqueue: writeback wb_workfn (flush-cifs-2)\n[  945.277457] RIP: 0010:crypto_gcm_init_common+0x1f9/0x220\n[  945.278018] Code: b0 00 00 00 48 83 c4 08 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 48 c7 c0 00 00 00 80 48 2b 05 5c 58 e5 00 e9 58 ff ff ff <0f> 0b 0f 0b 0f 0b 0f 0b 0f 0b 0f 0b 48 c7 04 24 01 00 00 00 48 8b\n[  945.279992] RSP: 0018:ffffc90000a27360 EFLAGS: 00010246\n[  945.280578] RAX: 0000000000000000 RBX: ffffc90001d85060 RCX: 0000000000000030\n[  945.281376] RDX: 0000000000080000 RSI: 0000000000000000 RDI: ffffc90081d85070\n[  945.282145] RBP: ffffc90001d85010 R08: ffffc90001d85000 R09: 0000000000000000\n[  945.282898] R10: ffffc90001d85090 R11: 0000000000001000 R12: ffffc90001d85070\n[  945.283656] R13: ffff888113522948 R14: ffffc90001d85060 R15: ffffc90001d85010\n[  945.284407] FS:  0000000000000000(0000) GS:ffff8882e66cf000(0000) knlGS:0000000000000000\n[  945.285262] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[  945.285884] CR2: 00007fa7ffdd31f4 CR3: 000000010540d000 CR4: 0000000000350ef0\n[  945.286683] Call Trace:\n[  945.286952]  <TASK>\n[  945.287184]  ? crypt_message+0x33f/0xad0 [cifs]\n[  945.287719]  crypto_gcm_encrypt+0x36/0xe0\n[  945.288152]  crypt_message+0x54a/0xad0 [cifs]\n[  945.288724]  smb3_init_transform_rq+0x277/0x300 [cifs]\n[  945.289300]  smb_send_rqst+0xa3/0x160 [cifs]\n[  945.289944]  cifs_call_async+0x178/0x340 [cifs]\n[  945.290514]  ? __pfx_smb2_writev_callback+0x10/0x10 [cifs]\n[  945.291177]  smb2_async_writev+0x3e3/0x670 [cifs]\n[  945.291759]  ? find_held_lock+0x32/0x90\n[  945.292212]  ? netfs_advance_write+0xf2/0x310\n[  945.292723]  netfs_advance_write+0xf2/0x310\n[  945.293210]  netfs_write_folio+0x346/0xcc0\n[  945.293689]  ? __pfx__raw_spin_unlock_irq+0x10/0x10\n[  945.294250]  netfs_writepages+0x117/0x460\n[  945.294724]  do_writepages+0xbe/0x170\n[  945.295152]  ? find_held_lock+0x32/0x90\n[  945.295600]  ? kvm_sched_clock_read+0x11/0x20\n[  945.296103]  __writeback_single_inode+0x56/0x4b0\n[  945.296643]  writeback_sb_inodes+0x229/0x550\n[  945.297140]  __writeback_inodes_wb+0x4c/0xe0\n[  945.297642]  wb_writeback+0x2f1/0x3f0\n[  945.298069]  wb_workfn+0x300/0x490\n[  945.298472]  process_one_work+0x1fe/0x590\n[  945.298949]  worker_thread+0x1ce/0x3c0\n[  945.299397]  ? __pfx_worker_thread+0x10/0x10\n[  945.299900]  kthr\n---truncated---"
    }
  ],
  "lastModified": "2026-06-17T09:21:11.180",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}