CVE-2023-52434

Status: ModifiedHigh (8)—

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

smb: client: fix potential OOBs in smb2_parse_contexts()

Validate offsets and lengths before dereferencing create contexts in smb2_parse_contexts().

This fixes following oops when accessing invalid create contexts from server:

Technical details traces, logs and code from the original report

  BUG: unable to handle page fault for address: ffff8881178d8cc3
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 4a01067 P4D 4a01067 PUD 0
  Oops: 0000 [#1] PREEMPT SMP NOPTI
  CPU: 3 PID: 1736 Comm: mount.cifs Not tainted 6.7.0-rc4 #1
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
  rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014
  RIP: 0010:smb2_parse_contexts+0xa0/0x3a0 [cifs]
  Code: f8 10 75 13 48 b8 93 ad 25 50 9c b4 11 e7 49 39 06 0f 84 d2 00
  00 00 8b 45 00 85 c0 74 61 41 29 c5 48 01 c5 41 83 fd 0f 76 55 <0f> b7
  7d 04 0f b7 45 06 4c 8d 74 3d 00 66 83 f8 04 75 bc ba 04 00
  RSP: 0018:ffffc900007939e0 EFLAGS: 00010216
  RAX: ffffc90000793c78 RBX: ffff8880180cc000 RCX: ffffc90000793c90
  RDX: ffffc90000793cc0 RSI: ffff8880178d8cc0 RDI: ffff8880180cc000
  RBP: ffff8881178d8cbf R08: ffffc90000793c22 R09: 0000000000000000
  R10: ffff8880180cc000 R11: 0000000000000024 R12: 0000000000000000
  R13: 0000000000000020 R14: 0000000000000000 R15: ffffc90000793c22
  FS: 00007f873753cbc0(0000) GS:ffff88806bc00000(0000)
  knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: ffff8881178d8cc3 CR3: 00000000181ca000 CR4: 0000000000750ef0
  PKRU: 55555554
  Call Trace:
   <TASK>
   ? __die+0x23/0x70
   ? page_fault_oops+0x181/0x480
   ? search_module_extables+0x19/0x60
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? exc_page_fault+0x1b6/0x1c0
   ? asm_exc_page_fault+0x26/0x30
   ? smb2_parse_contexts+0xa0/0x3a0 [cifs]
   SMB2_open+0x38d/0x5f0 [cifs]
   ? smb2_is_path_accessible+0x138/0x260 [cifs]
   smb2_is_path_accessible+0x138/0x260 [cifs]
   cifs_is_path_remote+0x8d/0x230 [cifs]
   cifs_mount+0x7e/0x350 [cifs]
   cifs_smb3_do_mount+0x128/0x780 [cifs]
   smb3_get_tree+0xd9/0x290 [cifs]
   vfs_get_tree+0x2c/0x100
   ? capable+0x37/0x70
   path_mount+0x2d7/0xb80
   ? srso_alias_return_thunk+0x5/0xfbef5
   ? _raw_spin_unlock_irqrestore+0x44/0x60
   __x64_sys_mount+0x11a/0x150
   do_syscall_64+0x47/0xf0
   entry_SYSCALL_64_after_hwframe+0x6f/0x77
  RIP: 0033:0x7f8737657b1e

CVSS

Version: 3.1
Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Base score: 8

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 1.02%
Percentile among all scored CVEs: 62
Score date: 10/8/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (2)

Debian — Debian Linux Linux — Linux Kernel

CWEs

CWE-119

References

Raw JSON (NVD)

Show

{
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      "source": "nvd@nist.gov",
      "description": [
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          "lang": "en",
          "value": "CWE-119"
        }
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  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix potential OOBs in smb2_parse_contexts()\n\nValidate offsets and lengths before dereferencing create contexts in\nsmb2_parse_contexts().\n\nThis fixes following oops when accessing invalid create contexts from\nserver:\n\n  BUG: unable to handle page fault for address: ffff8881178d8cc3\n  #PF: supervisor read access in kernel mode\n  #PF: error_code(0x0000) - not-present page\n  PGD 4a01067 P4D 4a01067 PUD 0\n  Oops: 0000 [#1] PREEMPT SMP NOPTI\n  CPU: 3 PID: 1736 Comm: mount.cifs Not tainted 6.7.0-rc4 #1\n  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS\n  rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014\n  RIP: 0010:smb2_parse_contexts+0xa0/0x3a0 [cifs]\n  Code: f8 10 75 13 48 b8 93 ad 25 50 9c b4 11 e7 49 39 06 0f 84 d2 00\n  00 00 8b 45 00 85 c0 74 61 41 29 c5 48 01 c5 41 83 fd 0f 76 55 <0f> b7\n  7d 04 0f b7 45 06 4c 8d 74 3d 00 66 83 f8 04 75 bc ba 04 00\n  RSP: 0018:ffffc900007939e0 EFLAGS: 00010216\n  RAX: ffffc90000793c78 RBX: ffff8880180cc000 RCX: ffffc90000793c90\n  RDX: ffffc90000793cc0 RSI: ffff8880178d8cc0 RDI: ffff8880180cc000\n  RBP: ffff8881178d8cbf R08: ffffc90000793c22 R09: 0000000000000000\n  R10: ffff8880180cc000 R11: 0000000000000024 R12: 0000000000000000\n  R13: 0000000000000020 R14: 0000000000000000 R15: ffffc90000793c22\n  FS: 00007f873753cbc0(0000) GS:ffff88806bc00000(0000)\n  knlGS:0000000000000000\n  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n  CR2: ffff8881178d8cc3 CR3: 00000000181ca000 CR4: 0000000000750ef0\n  PKRU: 55555554\n  Call Trace:\n   <TASK>\n   ? __die+0x23/0x70\n   ? page_fault_oops+0x181/0x480\n   ? search_module_extables+0x19/0x60\n   ? srso_alias_return_thunk+0x5/0xfbef5\n   ? exc_page_fault+0x1b6/0x1c0\n   ? asm_exc_page_fault+0x26/0x30\n   ? smb2_parse_contexts+0xa0/0x3a0 [cifs]\n   SMB2_open+0x38d/0x5f0 [cifs]\n   ? smb2_is_path_accessible+0x138/0x260 [cifs]\n   smb2_is_path_accessible+0x138/0x260 [cifs]\n   cifs_is_path_remote+0x8d/0x230 [cifs]\n   cifs_mount+0x7e/0x350 [cifs]\n   cifs_smb3_do_mount+0x128/0x780 [cifs]\n   smb3_get_tree+0xd9/0x290 [cifs]\n   vfs_get_tree+0x2c/0x100\n   ? capable+0x37/0x70\n   path_mount+0x2d7/0xb80\n   ? srso_alias_return_thunk+0x5/0xfbef5\n   ? _raw_spin_unlock_irqrestore+0x44/0x60\n   __x64_sys_mount+0x11a/0x150\n   do_syscall_64+0x47/0xf0\n   entry_SYSCALL_64_after_hwframe+0x6f/0x77\n  RIP: 0033:0x7f8737657b1e"
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se resolvió la siguiente vulnerabilidad: smb: cliente: corrige OOB potenciales en smb2_parse_contexts() Valida compensaciones y longitudes antes de desreferenciar crea contextos en smb2_parse_contexts(). Esto corrige los siguientes errores al acceder a contextos de creación no válidos desde el servidor: ERROR: no se puede manejar el error de página para la dirección: ffff8881178d8cc3 #PF: acceso de lectura del supervisor en modo kernel #PF: error_code(0x0000) - página no presente PGD 4a01067 P4D 4a01067 PUD 0 Ups: 0000 [#1] PREEMPT SMP NOPTI CPU: 3 PID: 1736 Comm: mount.cifs No está contaminado 6.7.0-rc4 #1 Nombre de hardware: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.2 -3-gd478f380-rebuilt.opensuse.org 04/04/2014 RIP: 0010: SMB2_PARSE_CONTEXTS+0XA0/0X3A0 [CIFS] Código: F8 10 75 13 48 B8 93 AD 25 50 9C B4 11 E7 49 39 06 0f 84 D2 00 00 00 8b 45 00 85 c0 74 61 41 29 c5 48 01 c5 41 83 fd 0f 76 55 &lt;0f&gt; b7 7d 04 0f b7 45 06 4c 8d 74 3d 00 66 83 f8 04 75 bc ba 04 00 RSP: 0018:ffffc900007939e0 EFLAGS: 00010216 RAX: ffffc90000793c78 RBX: ffff8880180cc000 RCX: ffffc90000793c90 RDX: ffffc90000793cc0 RSI: ffff8880178d8cc0 RDI: ffff8880180cc000 RBP: ffff8881178d8cbf R08: ffffc90000793c22 R09: 0000000000000000 R10: ffff8880180cc000 R11: 00000000000000024 R12: 0000000000000000 R13: 0000000 000000020 R14: 00000000000000000 R15: ffffc90000793c22 FS: 00007f873753cbc0(0000) GS:ffff88806bc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff8881178d8cc3 CR3 : 00000000181ca000 CR4: 0000000000750ef0 PKRU: 55555554 Seguimiento de llamadas:  ? __morir+0x23/0x70 ? page_fault_oops+0x181/0x480? search_module_extables+0x19/0x60? srso_alias_return_thunk+0x5/0xfbef5? exc_page_fault+0x1b6/0x1c0? asm_exc_page_fault+0x26/0x30? smb2_parse_contexts+0xa0/0x3a0 [cifs] SMB2_open+0x38d/0x5f0 [cifs] ? smb2_is_path_accessible+0x138/0x260 [cifs] smb2_is_path_accessible+0x138/0x260 [cifs] cifs_is_path_remote+0x8d/0x230 [cifs] cifs_mount+0x7e/0x350 [cifs] cifs_smb3_do_mount+0x128/0x7 80 [cifs] smb3_get_tree+0xd9/0x290 [cifs] vfs_get_tree+ 0x2c/0x100? capaz+0x37/0x70 path_mount+0x2d7/0xb80? srso_alias_return_thunk+0x5/0xfbef5? _raw_spin_unlock_irqrestore+0x44/0x60 __x64_sys_mount+0x11a/0x150 do_syscall_64+0x47/0xf0 Entry_SYSCALL_64_after_hwframe+0x6f/0x77 RIP: 0033:0x7f8737657b1e"
    }
  ],
  "lastModified": "2026-08-04T10:18:26.637",
  "configurations": [
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