CVE-2022-50320
Description
From CVE.org
In the Linux kernel, the following vulnerability has been resolved: ACPI: tables: FPDT: Don't call acpi_os_map_memory() on invalid phys address On a Packard Bell Dot SC (Intel Atom N2600 model) there is a FPDT table which contains invalid physical addresses, with high bits set which fall outside the range of the CPU-s supported physical address range. Calling acpi_os_map_memory() on such an invalid phys address leads to the below WARN_ON in ioremap triggering resulting in an oops/stacktrace. Add code to verify the physical address before calling acpi_os_map_memory() to fix / avoid the oops. [ 1.226900] ioremap: invalid physical address 3001000000000000 [ 1.226949] ------------[ cut here ]------------ [ 1.226962] WARNING: CPU: 1 PID: 1 at arch/x86/mm/ioremap.c:200 __ioremap_caller.cold+0x43/0x5f [ 1.226996] Modules linked in: [ 1.227016] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 6.0.0-rc3+ #490 [ 1.227029] Hardware name: Packard Bell dot s/SJE01_CT, BIOS V1.10 07/23/2013 [ 1.227038] RIP: 0010:__ioremap_caller.cold+0x43/0x5f [ 1.227054] Code: 96 00 00 e9 f8 af 24 ff 89 c6 48 c7 c7 d8 0c 84 99 e8 6a 96 00 00 e9 76 af 24 ff 48 89 fe 48 c7 c7 a8 0c 84 99 e8 56 96 00 00 <0f> 0b e9 60 af 24 ff 48 8b 34 24 48 c7 c7 40 0d 84 99 e8 3f 96 00 [ 1.227067] RSP: 0000:ffffb18c40033d60 EFLAGS: 00010286 [ 1.227084] RAX: 0000000000000032 RBX: 3001000000000000 RCX: 0000000000000000 [ 1.227095] RDX: 0000000000000001 RSI: 00000000ffffdfff RDI: 00000000ffffffff [ 1.227105] RBP: 3001000000000000 R08: 0000000000000000 R09: ffffb18c40033c18 [ 1.227115] R10: 0000000000000003 R11: ffffffff99d62fe8 R12: 0000000000000008 [ 1.227124] R13: 0003001000000000 R14: 0000000000001000 R15: 3001000000000000 [ 1.227135] FS: 0000000000000000(0000) GS:ffff913a3c080000(0000) knlGS:0000000000000000 [ 1.227146] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1.227156] CR2: 0000000000000000 CR3: 0000000018c26000 CR4: 00000000000006e0 [ 1.227167] Call Trace: [ 1.227176] <TASK> [ 1.227185] ? acpi_os_map_iomem+0x1c9/0x1e0 [ 1.227215] ? kmem_cache_alloc_trace+0x187/0x370 [ 1.227254] acpi_os_map_iomem+0x1c9/0x1e0 [ 1.227288] acpi_init_fpdt+0xa8/0x253 [ 1.227308] ? acpi_debugfs_init+0x1f/0x1f [ 1.227339] do_one_initcall+0x5a/0x300 [ 1.227406] ? rcu_read_lock_sched_held+0x3f/0x80 [ 1.227442] kernel_init_freeable+0x28b/0x2cc [ 1.227512] ? rest_init+0x170/0x170 [ 1.227538] kernel_init+0x16/0x140 [ 1.227552] ret_from_fork+0x1f/0x30 [ 1.227639] </TASK> [ 1.227647] irq event stamp: 186819 [ 1.227656] hardirqs last enabled at (186825): [<ffffffff98184a6e>] __up_console_sem+0x5e/0x70 [ 1.227672] hardirqs last disabled at (186830): [<ffffffff98184a53>] __up_console_sem+0x43/0x70 [ 1.227686] softirqs last enabled at (186576): [<ffffffff980fbc9d>] __irq_exit_rcu+0xed/0x160 [ 1.227701] softirqs last disabled at (186569): [<ffffffff980fbc9d>] __irq_exit_rcu+0xed/0x160 [ 1.227715] ---[ end trace 0000000000000000 ]---
Statement
The bug in the ACPI FPDT parser could cause a kernel crash during boot on systems with firmware tables containing invalid physical addresses. It cannot be exploited remotely, as the invalid values originate from BIOS/UEFI tables, making it a reliability issue rather than a security risk. The patch ensures that only valid physical addresses are passed to acpi_os_map_memory(), preventing such boot-time crashes.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 4.6 | 7.8 | N/A |
| Attack Vector | Physical | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | High | N/A |
| Integrity Impact | None | High | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)
Resources including CPU, memory, and stack memory could be rapidly consumed or exhausted, eventually leading to an exit or crash.
Confidentiality
Technical Impact: Read Application Data
In some cases, an application's interpreter might kill a process or thread that appears to be consuming too much resources, such as with PHP's memory_limit setting. When the interpreter kills the process/thread, it might report an error containing detailed information such as the application's installation path.
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