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Vulnerability · Published May 22, 2024 · Assigned by Linux

CVE-2021-47463mm/secretmem: fix NULL page->mapping dereference in page_is_secretmem()

Medium 5.5

In plain English

A medium-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)5.5Medium
Exploit odds (30 days)0.2%top 92.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

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

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux5.14.16-1DEBIAN-CVE-2021-47463
Debian:13linux5.14.16-1DEBIAN-CVE-2021-47463
Debian:14linux5.14.16-1DEBIAN-CVE-2021-47463
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2021-47463
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2021-47463
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2021-47463
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2021-47463
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2021-47463
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2021-47463
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2021-47463
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2021-47463
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2021-47463
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2021-47463
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2021-47463
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2021-47463
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2021-47463
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2021-47463
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2021-47463
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2021-47463
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2021-47463
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2021-47463
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2021-47463
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2021-47463
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2021-47463

Affected products (as reported)

VendorProductVersions
Linux Linux 1507f51255c9ff07d75909a84e7c0d7f3c4b2f49 – before b77ba1e02345bafd703f0d407bdbd88c3be1f7671507f51255c9ff07d75909a84e7c0d7f3c4b2f49 – before 79f9bc5843142b649575f887dccdf1c07ad75c20
Linux Linux 5.14

References