Linux: Out-of-bounds Write
CVE-2022-50320 is a high-severity out-of-bounds write vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 30eca146c89d216dda95868ce00a2d35cf73d5a4, 90bfc9ae875dfbed2e6089516520204cd431dba3, 16046a716c8e1f447909bec9b478d58e6e25e513 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.17% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 30eca146c89d216dda95868ce00a2d35cf73d5a4 or 90bfc9ae875dfbed2e6089516520204cd431dba3 or 16046a716c8e1f447909bec9b478d58e6e25e513 or 211391bf04b3c74e250c566eeff9cf808156c693, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.15.75 or 5.19.17 or 6.0.3, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | d1eb86e59be09c12447fcb959783cbc70a9bec01 up to, but not including, 30eca146c89d216dda95868ce00a2d35cf73d5a4; d1eb86e59be09c12447fcb959783cbc70a9bec01 up to, but not including, 90bfc9ae875dfbed2e6089516520204cd431dba3; d1eb86e59be09c12447fcb959783cbc70a9bec01 up to, but not including, 16046a716c8e1f447909bec9b478d58e6e25e513; d1eb86e59be09c12447fcb959783cbc70a9bec01 up to, but not including, 211391bf04b3c74e250c566eeff9cf808156c693; 5.12 | 30eca146c89d216dda95868ce00a2d35cf73d5a4, 90bfc9ae875dfbed2e6089516520204cd431dba3, 16046a716c8e1f447909bec9b478d58e6e25e513, 211391bf04b3c74e250c566eeff9cf808156c693 |
| Linux | Linux Kernel | before 5.15.75; 5.16 up to, but not including, 5.19.17; 6.0 up to, but not including, 6.0.3 | 5.15.75, 5.19.17, 6.0.3 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
Official description
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 ]---
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Write
The product writes data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Out-of-bounds Write vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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