Vulnerability Details : CVE-2021-47463
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
Vulnerability category: Memory Corruption
Products affected by CVE-2021-47463
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.15:rc3:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.15:rc4:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.15:rc5:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.15:rc6:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-47463
0.04%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 9 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-47463
Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
---|---|---|---|---|---|---|
5.5
|
MEDIUM | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
1.8
|
3.6
|
NIST | 2025-01-15 |
CWE ids for CVE-2021-47463
-
The product dereferences a pointer that it expects to be valid but is NULL.Assigned by: nvd@nist.gov (Primary)
References for CVE-2021-47463
-
https://git.kernel.org/stable/c/b77ba1e02345bafd703f0d407bdbd88c3be1f767
mm/secretmem: fix NULL page->mapping dereference in page_is_secretmem() - kernel/git/stable/linux.git - Linux kernel stable treePatch
-
https://git.kernel.org/stable/c/79f9bc5843142b649575f887dccdf1c07ad75c20
mm/secretmem: fix NULL page->mapping dereference in page_is_secretmem() - kernel/git/stable/linux.git - Linux kernel stable treePatch
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