// For flags

CVE-2021-47463

mm/secretmem: fix NULL page->mapping dereference in page_is_secretmem()

Severity Score

"-"
*CVSS v-

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

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

mm/secretmem: fix NULL page->mapping dereference in page_is_secretmem()

Check for a NULL page->mapping before dereferencing the mapping in
page_is_secretmem(), as the page's mapping can be nullified while gup()
is running, e.g. by reclaim or truncation.

BUG: kernel NULL pointer dereference, address: 0000000000000068
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
CPU: 6 PID: 4173897 Comm: CPU 3/KVM Tainted: G W
RIP: 0010:internal_get_user_pages_fast+0x621/0x9d0
Code: <48> 81 7a 68 80 08 04 bc 0f 85 21 ff ff 8 89 c7 be
RSP: 0018:ffffaa90087679b0 EFLAGS: 00010046
RAX: ffffe3f37905b900 RBX: 00007f2dd561e000 RCX: ffffe3f37905b934
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffe3f37905b900
...
CR2: 0000000000000068 CR3: 00000004c5898003 CR4: 00000000001726e0
Call Trace:
get_user_pages_fast_only+0x13/0x20
hva_to_pfn+0xa9/0x3e0
try_async_pf+0xa1/0x270
direct_page_fault+0x113/0xad0
kvm_mmu_page_fault+0x69/0x680
vmx_handle_exit+0xe1/0x5d0
kvm_arch_vcpu_ioctl_run+0xd81/0x1c70
kvm_vcpu_ioctl+0x267/0x670
__x64_sys_ioctl+0x83/0xa0
do_syscall_64+0x56/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: mm/secretmem: corrige la página NULL-&gt;desreferencia de mapeo en page_is_secretmem() Verifique si hay una página NULL-&gt;mapping antes de desreferenciar el mapeo en page_is_secretmem(), ya que el mapeo de la página puede ser anulado mientras se ejecuta gup(), por ejemplo, mediante recuperación o truncamiento. ERROR: desreferencia del puntero NULL del kernel, dirección: 00000000000000068 #PF: acceso de lectura del supervisor en modo kernel #PF: código_error(0x0000) - página no presente PGD 0 P4D 0 Ups: 0000 [#1] PREEMPT SMP NOPTI CPU: 6 PID: 4173897 Comunicaciones: CPU 3/KVM contaminada: GW RIP: 0010:internal_get_user_pages_fast+0x621/0x9d0 Código: &lt;48&gt; 81 7a 68 80 08 04 bc 0f 85 21 ff ff 8 89 c7 be RSP: ffffaa90087679 b0 EFLAGS: 00010046 RAX: ffffe3f37905b900 RBX: 00007f2dd561e000 RCX: ffffe3f37905b934 RDX: 0000000000000000 RSI: 00000000000000000 RDI: ffffe3f37905b900 ... CR2: 0000068 CR3: 00000004c5898003 CR4: 00000000001726e0 Seguimiento de llamadas: get_user_pages_fast_only+0x13/0x20 hva_to_pfn+0xa9/0x3e0 try_async_pf+0xa1/0x270 direct_page_fault+0x113/ 0xad0 kvm_mmu_page_fault+0x69/0x680 vmx_handle_exit+0xe1/0x5d0 kvm_arch_vcpu_ioctl_run+0xd81/0x1c70 kvm_vcpu_ioctl+0x267/0x670 __x64_sys_ioctl+0x83/0xa0 scall_64+0x56/0x80 entrada_SYSCALL_64_after_hwframe+0x44/0xae

*Credits: N/A
CVSS Scores
Attack Vector
-
Attack Complexity
-
Privileges Required
-
User Interaction
-
Scope
-
Confidentiality
-
Integrity
-
Availability
-
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2024-05-22 CVE Reserved
  • 2024-05-22 CVE Published
  • 2024-05-22 EPSS Updated
  • 2024-08-04 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 5.14 < 5.14.15
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.14 < 5.14.15"
en
Affected
Linux
Search vendor "Linux"
 Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
 >= 5.14 < 5.15
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.14 < 5.15"
en
Affected