CVE Vulnerabilities

CVE-2025-21866

Allocation of Resources Without Limits or Throttling

Published: Mar 12, 2025 | Modified: Mar 13, 2025
CVSS 3.x
5.5
MEDIUM
Source:
NVD
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CVSS 2.x
RedHat/V2
RedHat/V3
5.5 LOW
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Ubuntu
MEDIUM

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

powerpc/code-patching: Fix KASAN hit by not flagging text patching area as VM_ALLOC

Erhard reported the following KASAN hit while booting his PowerMac G4 with a KASAN-enabled kernel 6.13-rc6:

BUG: KASAN: vmalloc-out-of-bounds in copy_to_kernel_nofault+0xd8/0x1c8 Write of size 8 at addr f1000000 by task chronyd/1293

CPU: 0 UID: 123 PID: 1293 Comm: chronyd Tainted: G W 6.13.0-rc6-PMacG4 #2 Tainted: [W]=WARN Hardware name: PowerMac3,6 7455 0x80010303 PowerMac Call Trace: [c2437590] [c1631a84] dump_stack_lvl+0x70/0x8c (unreliable) [c24375b0] [c0504998] print_report+0xdc/0x504 [c2437610] [c050475c] kasan_report+0xf8/0x108 [c2437690] [c0505a3c] kasan_check_range+0x24/0x18c [c24376a0] [c03fb5e4] copy_to_kernel_nofault+0xd8/0x1c8 [c24376c0] [c004c014] patch_instructions+0x15c/0x16c [c2437710] [c00731a8] bpf_arch_text_copy+0x60/0x7c [c2437730] [c0281168] bpf_jit_binary_pack_finalize+0x50/0xac [c2437750] [c0073cf4] bpf_int_jit_compile+0xb30/0xdec [c2437880] [c0280394] bpf_prog_select_runtime+0x15c/0x478 [c24378d0] [c1263428] bpf_prepare_filter+0xbf8/0xc14 [c2437990] [c12677ec] bpf_prog_create_from_user+0x258/0x2b4 [c24379d0] [c027111c] do_seccomp+0x3dc/0x1890 [c2437ac0] [c001d8e0] system_call_exception+0x2dc/0x420 [c2437f30] [c00281ac] ret_from_syscall+0x0/0x2c — interrupt: c00 at 0x5a1274 NIP: 005a1274 LR: 006a3b3c CTR: 005296c8 REGS: c2437f40 TRAP: 0c00 Tainted: G W (6.13.0-rc6-PMacG4) MSR: 0200f932 <VEC,EE,PR,FP,ME,IR,DR,RI> CR: 24004422 XER: 00000000

GPR00: 00000166 af8f3fa0 a7ee3540 00000001 00000000 013b6500 005a5858 0200f932 GPR08: 00000000 00001fe9 013d5fc8 005296c8 2822244c 00b2fcd8 00000000 af8f4b57 GPR16: 00000000 00000001 00000000 00000000 00000000 00000001 00000000 00000002 GPR24: 00afdbb0 00000000 00000000 00000000 006e0004 013ce060 006e7c1c 00000001 NIP [005a1274] 0x5a1274 LR [006a3b3c] 0x6a3b3c — interrupt: c00

The buggy address belongs to the virtual mapping at [f1000000, f1002000) created by: text_area_cpu_up+0x20/0x190

The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:00000000 index:0x0 pfn:0x76e30 flags: 0x80000000(zone=2) raw: 80000000 00000000 00000122 00000000 00000000 00000000 ffffffff 00000001 raw: 00000000 page dumped because: kasan: bad access detected

Memory state around the buggy address: f0ffff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f0ffff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

f1000000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ^ f1000080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f1000100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ==================================================================

f8 corresponds to KASAN_VMALLOC_INVALID which means the area is not initialised hence not supposed to be used yet.

Powerpc text patching infrastructure allocates a virtual memory area using get_vm_area() and flags it as VM_ALLOC. But that flag is meant to be used for vmalloc() and vmalloc() allocated memory is not supposed to be used before a call to __vmalloc_node_range() which is never called for that area.

That went undetected until commit e4137f08816b (mm, kasan, kmsan: instrument copy_from/to_kernel_nofault)

The area allocated by text_area_cpu_up() is not vmalloc memory, it is mapped directly on demand when needed by map_kernel_page(). There is no VM flag corresponding to such usage, so just pass no flag. That way the area will be unpoisonned and usable immediately.

Weakness

The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor.

Affected Software

Name Vendor Start Version End Version
Linux_kernel Linux 4.13 (including) 6.1.130 (excluding)
Linux_kernel Linux 6.2 (including) 6.6.80 (excluding)
Linux_kernel Linux 6.7 (including) 6.12.17 (excluding)
Linux_kernel Linux 6.13 (including) 6.13.5 (excluding)
Linux_kernel Linux 6.14-rc1 (including) 6.14-rc1 (including)
Linux_kernel Linux 6.14-rc2 (including) 6.14-rc2 (including)
Linux_kernel Linux 6.14-rc3 (including) 6.14-rc3 (including)
Linux Ubuntu bionic *
Linux Ubuntu esm-infra/bionic *
Linux Ubuntu focal *
Linux Ubuntu jammy *
Linux Ubuntu noble *
Linux Ubuntu oracular *
Linux Ubuntu upstream *
Linux-allwinner-5.19 Ubuntu jammy *
Linux-allwinner-5.19 Ubuntu upstream *
Linux-aws Ubuntu bionic *
Linux-aws Ubuntu esm-infra/bionic *
Linux-aws Ubuntu focal *
Linux-aws Ubuntu jammy *
Linux-aws Ubuntu noble *
Linux-aws Ubuntu oracular *
Linux-aws Ubuntu upstream *
Linux-aws-5.0 Ubuntu bionic *
Linux-aws-5.0 Ubuntu esm-infra/bionic *
Linux-aws-5.0 Ubuntu upstream *
Linux-aws-5.11 Ubuntu focal *
Linux-aws-5.11 Ubuntu upstream *
Linux-aws-5.13 Ubuntu focal *
Linux-aws-5.13 Ubuntu upstream *
Linux-aws-5.15 Ubuntu focal *
Linux-aws-5.15 Ubuntu upstream *
Linux-aws-5.19 Ubuntu jammy *
Linux-aws-5.19 Ubuntu upstream *
Linux-aws-5.3 Ubuntu bionic *
Linux-aws-5.3 Ubuntu esm-infra/bionic *
Linux-aws-5.3 Ubuntu upstream *
Linux-aws-5.4 Ubuntu bionic *
Linux-aws-5.4 Ubuntu esm-infra/bionic *
Linux-aws-5.4 Ubuntu upstream *
Linux-aws-5.8 Ubuntu focal *
Linux-aws-5.8 Ubuntu upstream *
Linux-aws-6.2 Ubuntu jammy *
Linux-aws-6.2 Ubuntu upstream *
Linux-aws-6.5 Ubuntu jammy *
Linux-aws-6.5 Ubuntu upstream *
Linux-aws-6.8 Ubuntu jammy *
Linux-aws-6.8 Ubuntu upstream *
Linux-aws-fips Ubuntu fips-preview/jammy *
Linux-aws-fips Ubuntu fips-updates/bionic *
Linux-aws-fips Ubuntu fips-updates/focal *
Linux-aws-fips Ubuntu fips-updates/jammy *
Linux-aws-fips Ubuntu fips/bionic *
Linux-aws-fips Ubuntu fips/focal *
Linux-aws-fips Ubuntu trusty *
Linux-aws-fips Ubuntu upstream *
Linux-aws-fips Ubuntu xenial *
Linux-aws-hwe Ubuntu esm-infra/xenial *
Linux-aws-hwe Ubuntu upstream *
Linux-aws-hwe Ubuntu xenial *
Linux-azure Ubuntu bionic *
Linux-azure Ubuntu esm-infra-legacy/trusty *
Linux-azure Ubuntu esm-infra/bionic *
Linux-azure Ubuntu esm-infra/xenial *
Linux-azure Ubuntu focal *
Linux-azure Ubuntu jammy *
Linux-azure Ubuntu noble *
Linux-azure Ubuntu oracular *
Linux-azure Ubuntu trusty *
Linux-azure Ubuntu trusty/esm *
Linux-azure Ubuntu upstream *
Linux-azure Ubuntu xenial *
Linux-azure-4.15 Ubuntu bionic *
Linux-azure-4.15 Ubuntu esm-infra/bionic *
Linux-azure-4.15 Ubuntu upstream *
Linux-azure-5.11 Ubuntu focal *
Linux-azure-5.11 Ubuntu upstream *
Linux-azure-5.13 Ubuntu focal *
Linux-azure-5.13 Ubuntu upstream *
Linux-azure-5.15 Ubuntu focal *
Linux-azure-5.15 Ubuntu upstream *
Linux-azure-5.19 Ubuntu jammy *
Linux-azure-5.19 Ubuntu upstream *
Linux-azure-5.3 Ubuntu bionic *
Linux-azure-5.3 Ubuntu esm-infra/bionic *
Linux-azure-5.3 Ubuntu upstream *
Linux-azure-5.4 Ubuntu bionic *
Linux-azure-5.4 Ubuntu esm-infra/bionic *
Linux-azure-5.4 Ubuntu upstream *
Linux-azure-5.8 Ubuntu focal *
Linux-azure-5.8 Ubuntu upstream *
Linux-azure-6.2 Ubuntu jammy *
Linux-azure-6.2 Ubuntu upstream *
Linux-azure-6.5 Ubuntu jammy *
Linux-azure-6.5 Ubuntu upstream *
Linux-azure-6.8 Ubuntu jammy *
Linux-azure-6.8 Ubuntu upstream *
Linux-azure-edge Ubuntu bionic *
Linux-azure-edge Ubuntu esm-infra/bionic *
Linux-azure-edge Ubuntu upstream *
Linux-azure-fde Ubuntu focal *
Linux-azure-fde Ubuntu jammy *
Linux-azure-fde Ubuntu upstream *
Linux-azure-fde-5.15 Ubuntu focal *
Linux-azure-fde-5.15 Ubuntu upstream *
Linux-azure-fde-5.19 Ubuntu jammy *
Linux-azure-fde-5.19 Ubuntu upstream *
Linux-azure-fde-6.2 Ubuntu jammy *
Linux-azure-fde-6.2 Ubuntu upstream *
Linux-azure-fips Ubuntu fips-preview/jammy *
Linux-azure-fips Ubuntu fips-updates/bionic *
Linux-azure-fips Ubuntu fips-updates/focal *
Linux-azure-fips Ubuntu fips-updates/jammy *
Linux-azure-fips Ubuntu fips/bionic *
Linux-azure-fips Ubuntu fips/focal *
Linux-azure-fips Ubuntu trusty *
Linux-azure-fips Ubuntu upstream *
Linux-azure-fips Ubuntu xenial *
Linux-bluefield Ubuntu bluefield/jammy *
Linux-bluefield Ubuntu focal *
Linux-bluefield Ubuntu upstream *
Linux-fips Ubuntu fips-preview/jammy *
Linux-fips Ubuntu fips-updates/bionic *
Linux-fips Ubuntu fips-updates/focal *
Linux-fips Ubuntu fips-updates/jammy *
Linux-fips Ubuntu fips/bionic *
Linux-fips Ubuntu fips/focal *
Linux-fips Ubuntu upstream *
Linux-gcp Ubuntu bionic *
Linux-gcp Ubuntu esm-infra/bionic *
Linux-gcp Ubuntu esm-infra/xenial *
Linux-gcp Ubuntu focal *
Linux-gcp Ubuntu jammy *
Linux-gcp Ubuntu noble *
Linux-gcp Ubuntu oracular *
Linux-gcp Ubuntu upstream *
Linux-gcp Ubuntu xenial *
Linux-gcp-4.15 Ubuntu bionic *
Linux-gcp-4.15 Ubuntu esm-infra/bionic *
Linux-gcp-4.15 Ubuntu upstream *
Linux-gcp-5.11 Ubuntu focal *
Linux-gcp-5.11 Ubuntu upstream *
Linux-gcp-5.13 Ubuntu focal *
Linux-gcp-5.13 Ubuntu upstream *
Linux-gcp-5.15 Ubuntu focal *
Linux-gcp-5.15 Ubuntu upstream *
Linux-gcp-5.19 Ubuntu jammy *
Linux-gcp-5.19 Ubuntu upstream *
Linux-gcp-5.3 Ubuntu bionic *
Linux-gcp-5.3 Ubuntu esm-infra/bionic *
Linux-gcp-5.3 Ubuntu upstream *
Linux-gcp-5.4 Ubuntu bionic *
Linux-gcp-5.4 Ubuntu esm-infra/bionic *
Linux-gcp-5.4 Ubuntu upstream *
Linux-gcp-5.8 Ubuntu focal *
Linux-gcp-5.8 Ubuntu upstream *
Linux-gcp-6.2 Ubuntu jammy *
Linux-gcp-6.2 Ubuntu upstream *
Linux-gcp-6.5 Ubuntu jammy *
Linux-gcp-6.5 Ubuntu upstream *
Linux-gcp-6.8 Ubuntu jammy *
Linux-gcp-6.8 Ubuntu upstream *
Linux-gcp-fips Ubuntu fips-preview/jammy *
Linux-gcp-fips Ubuntu fips-updates/bionic *
Linux-gcp-fips Ubuntu fips-updates/focal *
Linux-gcp-fips Ubuntu fips-updates/jammy *
Linux-gcp-fips Ubuntu fips/bionic *
Linux-gcp-fips Ubuntu fips/focal *
Linux-gcp-fips Ubuntu trusty *
Linux-gcp-fips Ubuntu upstream *
Linux-gcp-fips Ubuntu xenial *
Linux-gke Ubuntu focal *
Linux-gke Ubuntu jammy *
Linux-gke Ubuntu noble *
Linux-gke Ubuntu upstream *
Linux-gke Ubuntu xenial *
Linux-gke-4.15 Ubuntu bionic *
Linux-gke-4.15 Ubuntu esm-infra/bionic *
Linux-gke-4.15 Ubuntu upstream *
Linux-gke-5.15 Ubuntu focal *
Linux-gke-5.15 Ubuntu upstream *
Linux-gke-5.4 Ubuntu bionic *
Linux-gke-5.4 Ubuntu esm-infra/bionic *
Linux-gke-5.4 Ubuntu upstream *
Linux-gkeop Ubuntu focal *
Linux-gkeop Ubuntu jammy *
Linux-gkeop Ubuntu noble *
Linux-gkeop Ubuntu upstream *
Linux-gkeop-5.15 Ubuntu focal *
Linux-gkeop-5.15 Ubuntu upstream *
Linux-gkeop-5.4 Ubuntu bionic *
Linux-gkeop-5.4 Ubuntu esm-infra/bionic *
Linux-gkeop-5.4 Ubuntu upstream *
Linux-hwe Ubuntu bionic *
Linux-hwe Ubuntu esm-infra/bionic *
Linux-hwe Ubuntu esm-infra/xenial *
Linux-hwe Ubuntu upstream *
Linux-hwe Ubuntu xenial *
Linux-hwe-5.11 Ubuntu focal *
Linux-hwe-5.11 Ubuntu upstream *
Linux-hwe-5.13 Ubuntu focal *
Linux-hwe-5.13 Ubuntu upstream *
Linux-hwe-5.15 Ubuntu focal *
Linux-hwe-5.15 Ubuntu upstream *
Linux-hwe-5.19 Ubuntu jammy *
Linux-hwe-5.19 Ubuntu upstream *
Linux-hwe-5.4 Ubuntu bionic *
Linux-hwe-5.4 Ubuntu esm-infra/bionic *
Linux-hwe-5.4 Ubuntu upstream *
Linux-hwe-5.8 Ubuntu focal *
Linux-hwe-5.8 Ubuntu upstream *
Linux-hwe-6.11 Ubuntu noble *
Linux-hwe-6.11 Ubuntu upstream *
Linux-hwe-6.2 Ubuntu jammy *
Linux-hwe-6.2 Ubuntu upstream *
Linux-hwe-6.5 Ubuntu jammy *
Linux-hwe-6.5 Ubuntu upstream *
Linux-hwe-6.8 Ubuntu jammy *
Linux-hwe-6.8 Ubuntu upstream *
Linux-hwe-edge Ubuntu bionic *
Linux-hwe-edge Ubuntu esm-infra/bionic *
Linux-hwe-edge Ubuntu esm-infra/xenial *
Linux-hwe-edge Ubuntu upstream *
Linux-hwe-edge Ubuntu xenial *
Linux-ibm Ubuntu focal *
Linux-ibm Ubuntu jammy *
Linux-ibm Ubuntu noble *
Linux-ibm Ubuntu upstream *
Linux-ibm-5.15 Ubuntu focal *
Linux-ibm-5.15 Ubuntu upstream *
Linux-ibm-5.4 Ubuntu bionic *
Linux-ibm-5.4 Ubuntu esm-infra/bionic *
Linux-ibm-5.4 Ubuntu upstream *
Linux-intel Ubuntu noble *
Linux-intel Ubuntu upstream *
Linux-intel-5.13 Ubuntu focal *
Linux-intel-5.13 Ubuntu upstream *
Linux-intel-iot-realtime Ubuntu realtime/jammy *
Linux-intel-iot-realtime Ubuntu upstream *
Linux-intel-iotg Ubuntu jammy *
Linux-intel-iotg Ubuntu upstream *
Linux-intel-iotg-5.15 Ubuntu focal *
Linux-intel-iotg-5.15 Ubuntu upstream *
Linux-iot Ubuntu focal *
Linux-iot Ubuntu upstream *
Linux-kvm Ubuntu bionic *
Linux-kvm Ubuntu esm-infra/bionic *
Linux-kvm Ubuntu focal *
Linux-kvm Ubuntu jammy *
Linux-kvm Ubuntu upstream *
Linux-lowlatency Ubuntu jammy *
Linux-lowlatency Ubuntu noble *
Linux-lowlatency Ubuntu oracular *
Linux-lowlatency Ubuntu upstream *
Linux-lowlatency-hwe-5.15 Ubuntu focal *
Linux-lowlatency-hwe-5.15 Ubuntu upstream *
Linux-lowlatency-hwe-5.19 Ubuntu jammy *
Linux-lowlatency-hwe-5.19 Ubuntu upstream *
Linux-lowlatency-hwe-6.11 Ubuntu noble *
Linux-lowlatency-hwe-6.11 Ubuntu upstream *
Linux-lowlatency-hwe-6.2 Ubuntu jammy *
Linux-lowlatency-hwe-6.2 Ubuntu upstream *
Linux-lowlatency-hwe-6.5 Ubuntu jammy *
Linux-lowlatency-hwe-6.5 Ubuntu upstream *
Linux-lowlatency-hwe-6.8 Ubuntu jammy *
Linux-lowlatency-hwe-6.8 Ubuntu upstream *
Linux-lts-xenial Ubuntu upstream *
Linux-nvidia Ubuntu jammy *
Linux-nvidia Ubuntu noble *
Linux-nvidia Ubuntu upstream *
Linux-nvidia-6.2 Ubuntu jammy *
Linux-nvidia-6.2 Ubuntu upstream *
Linux-nvidia-6.5 Ubuntu jammy *
Linux-nvidia-6.5 Ubuntu upstream *
Linux-nvidia-6.8 Ubuntu jammy *
Linux-nvidia-6.8 Ubuntu upstream *
Linux-nvidia-lowlatency Ubuntu noble *
Linux-nvidia-lowlatency Ubuntu upstream *
Linux-nvidia-tegra Ubuntu jammy *
Linux-nvidia-tegra Ubuntu noble *
Linux-nvidia-tegra Ubuntu upstream *
Linux-nvidia-tegra-igx Ubuntu jammy *
Linux-nvidia-tegra-igx Ubuntu upstream *
Linux-oem Ubuntu bionic *
Linux-oem Ubuntu esm-infra/bionic *
Linux-oem Ubuntu upstream *
Linux-oem Ubuntu xenial *
Linux-oem-5.10 Ubuntu focal *
Linux-oem-5.10 Ubuntu upstream *
Linux-oem-5.13 Ubuntu focal *
Linux-oem-5.13 Ubuntu upstream *
Linux-oem-5.14 Ubuntu focal *
Linux-oem-5.14 Ubuntu upstream *
Linux-oem-5.17 Ubuntu jammy *
Linux-oem-5.17 Ubuntu upstream *
Linux-oem-5.6 Ubuntu focal *
Linux-oem-5.6 Ubuntu upstream *
Linux-oem-6.0 Ubuntu jammy *
Linux-oem-6.0 Ubuntu upstream *
Linux-oem-6.1 Ubuntu jammy *
Linux-oem-6.1 Ubuntu upstream *
Linux-oem-6.11 Ubuntu noble *
Linux-oem-6.11 Ubuntu upstream *
Linux-oem-6.5 Ubuntu jammy *
Linux-oem-6.5 Ubuntu upstream *
Linux-oem-6.8 Ubuntu noble *
Linux-oem-6.8 Ubuntu upstream *
Linux-oracle Ubuntu bionic *
Linux-oracle Ubuntu esm-infra/bionic *
Linux-oracle Ubuntu esm-infra/xenial *
Linux-oracle Ubuntu focal *
Linux-oracle Ubuntu jammy *
Linux-oracle Ubuntu noble *
Linux-oracle Ubuntu oracular *
Linux-oracle Ubuntu upstream *
Linux-oracle Ubuntu xenial *
Linux-oracle-5.0 Ubuntu bionic *
Linux-oracle-5.0 Ubuntu esm-infra/bionic *
Linux-oracle-5.0 Ubuntu upstream *
Linux-oracle-5.11 Ubuntu focal *
Linux-oracle-5.11 Ubuntu upstream *
Linux-oracle-5.13 Ubuntu focal *
Linux-oracle-5.13 Ubuntu upstream *
Linux-oracle-5.15 Ubuntu focal *
Linux-oracle-5.15 Ubuntu upstream *
Linux-oracle-5.3 Ubuntu bionic *
Linux-oracle-5.3 Ubuntu esm-infra/bionic *
Linux-oracle-5.3 Ubuntu upstream *
Linux-oracle-5.4 Ubuntu bionic *
Linux-oracle-5.4 Ubuntu esm-infra/bionic *
Linux-oracle-5.4 Ubuntu upstream *
Linux-oracle-5.8 Ubuntu focal *
Linux-oracle-5.8 Ubuntu upstream *
Linux-oracle-6.5 Ubuntu jammy *
Linux-oracle-6.5 Ubuntu upstream *
Linux-oracle-6.8 Ubuntu jammy *
Linux-oracle-6.8 Ubuntu upstream *
Linux-raspi Ubuntu focal *
Linux-raspi Ubuntu jammy *
Linux-raspi Ubuntu noble *
Linux-raspi Ubuntu oracular *
Linux-raspi Ubuntu upstream *
Linux-raspi-5.4 Ubuntu bionic *
Linux-raspi-5.4 Ubuntu esm-infra/bionic *
Linux-raspi-5.4 Ubuntu upstream *
Linux-raspi-realtime Ubuntu realtime/noble *
Linux-raspi-realtime Ubuntu upstream *
Linux-raspi2 Ubuntu bionic *
Linux-raspi2 Ubuntu focal *
Linux-raspi2 Ubuntu upstream *
Linux-raspi2 Ubuntu xenial *
Linux-realtime Ubuntu jammy *
Linux-realtime Ubuntu noble *
Linux-realtime Ubuntu oracular *
Linux-realtime Ubuntu realtime/jammy *
Linux-realtime Ubuntu realtime/noble *
Linux-realtime Ubuntu upstream *
Linux-riscv Ubuntu focal *
Linux-riscv Ubuntu jammy *
Linux-riscv Ubuntu noble *
Linux-riscv Ubuntu oracular *
Linux-riscv Ubuntu upstream *
Linux-riscv-5.11 Ubuntu focal *
Linux-riscv-5.11 Ubuntu upstream *
Linux-riscv-5.15 Ubuntu focal *
Linux-riscv-5.15 Ubuntu upstream *
Linux-riscv-5.19 Ubuntu jammy *
Linux-riscv-5.19 Ubuntu upstream *
Linux-riscv-5.8 Ubuntu focal *
Linux-riscv-5.8 Ubuntu upstream *
Linux-riscv-6.5 Ubuntu jammy *
Linux-riscv-6.5 Ubuntu upstream *
Linux-riscv-6.8 Ubuntu jammy *
Linux-riscv-6.8 Ubuntu upstream *
Linux-starfive-5.19 Ubuntu jammy *
Linux-starfive-5.19 Ubuntu upstream *
Linux-starfive-6.2 Ubuntu jammy *
Linux-starfive-6.2 Ubuntu upstream *
Linux-starfive-6.5 Ubuntu jammy *
Linux-starfive-6.5 Ubuntu upstream *
Linux-xilinx-zynqmp Ubuntu focal *
Linux-xilinx-zynqmp Ubuntu jammy *
Linux-xilinx-zynqmp Ubuntu upstream *

Extended Description

Code frequently has to work with limited resources, so programmers must be careful to ensure that resources are not consumed too quickly, or too easily. Without use of quotas, resource limits, or other protection mechanisms, it can be easy for an attacker to consume many resources by rapidly making many requests, or causing larger resources to be used than is needed. When too many resources are allocated, or if a single resource is too large, then it can prevent the code from working correctly, possibly leading to a denial of service.

Potential Mitigations

  • Assume all input is malicious. Use an “accept known good” input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.

  • When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, “boat” may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as “red” or “blue.”

  • Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code’s environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.

  • Mitigation of resource exhaustion attacks requires that the target system either:

  • The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.

  • The second solution can be difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply requires more resources on the part of the attacker.

  • If the program must fail, ensure that it fails gracefully (fails closed). There may be a temptation to simply let the program fail poorly in cases such as low memory conditions, but an attacker may be able to assert control before the software has fully exited. Alternately, an uncontrolled failure could cause cascading problems with other downstream components; for example, the program could send a signal to a downstream process so the process immediately knows that a problem has occurred and has a better chance of recovery.

  • Ensure that all failures in resource allocation place the system into a safe posture.

  • Use resource-limiting settings provided by the operating system or environment. For example, when managing system resources in POSIX, setrlimit() can be used to set limits for certain types of resources, and getrlimit() can determine how many resources are available. However, these functions are not available on all operating systems.

  • When the current levels get close to the maximum that is defined for the application (see CWE-770), then limit the allocation of further resources to privileged users; alternately, begin releasing resources for less-privileged users. While this mitigation may protect the system from attack, it will not necessarily stop attackers from adversely impacting other users.

  • Ensure that the application performs the appropriate error checks and error handling in case resources become unavailable (CWE-703).

References