Cyber Resilience

CVE-2023-52761

DoS in Linux Kernel 4.15 – 6.5.13

Published
21 May 2024
Modified
04 August 2026
Patch / advisory
CVSS Score v3.1 7.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0027 19th percentile
Risk Priority 56 floored blend · peak EPSS

Summary

CVE-2023-52761 is a high-severity Uncontrolled Recursion (CWE-674) vulnerability in Linux Linux Kernel. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked at the 19th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and SC-5 (Denial-of-service Protection) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

In the Linux kernel, the following vulnerability has been resolved: riscv: VMAP_STACK overflow detection thread-safe commit 31da94c25aea ("riscv: add VMAP_STACK overflow detection") added support for CONFIG_VMAP_STACK. If overflow is detected, CPU switches to `shadow_stack` temporarily before switching finally to per-cpu…

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`overflow_stack`. If two CPUs/harts are racing and end up in over flowing kernel stack, one or both will end up corrupting each other state because `shadow_stack` is not per-cpu. This patch optimizes per-cpu overflow stack switch by directly picking per-cpu `overflow_stack` and gets rid of `shadow_stack`. Following are the changes in this patch - Defines an asm macro to obtain per-cpu symbols in destination register. - In entry.S, when overflow is detected, per-cpu overflow stack is located using per-cpu asm macro. Computing per-cpu symbol requires a temporary register. x31 is saved away into CSR_SCRATCH (CSR_SCRATCH is anyways zero since we're in kernel). Please see Links for additional relevant disccussion and alternative solution. Tested by `echo EXHAUST_STACK > /sys/kernel/debug/provoke-crash/DIRECT` Kernel crash log below Insufficient stack space to handle exception!/debug/provoke-crash/DIRECT Task stack: [0xff20000010a98000..0xff20000010a9c000] Overflow stack: [0xff600001f7d98370..0xff600001f7d99370] CPU: 1 PID: 205 Comm: bash Not tainted 6.1.0-rc2-00001-g328a1f96f7b9 #34 Hardware name: riscv-virtio,qemu (DT) epc : __memset+0x60/0xfc ra : recursive_loop+0x48/0xc6 [lkdtm] epc : ffffffff808de0e4 ra : ffffffff0163a752 sp : ff20000010a97e80 gp : ffffffff815c0330 tp : ff600000820ea280 t0 : ff20000010a97e88 t1 : 000000000000002e t2 : 3233206874706564 s0 : ff20000010a982b0 s1 : 0000000000000012 a0 : ff20000010a97e88 a1 : 0000000000000000 a2 : 0000000000000400 a3 : ff20000010a98288 a4 : 0000000000000000 a5 : 0000000000000000 a6 : fffffffffffe43f0 a7 : 00007fffffffffff s2 : ff20000010a97e88 s3 : ffffffff01644680 s4 : ff20000010a9be90 s5 : ff600000842ba6c0 s6 : 00aaaaaac29e42b0 s7 : 00fffffff0aa3684 s8 : 00aaaaaac2978040 s9 : 0000000000000065 s10: 00ffffff8a7cad10 s11: 00ffffff8a76a4e0 t3 : ffffffff815dbaf4 t4 : ffffffff815dbaf4 t5 : ffffffff815dbab8 t6 : ff20000010a9bb48 status: 0000000200000120 badaddr: ff20000010a97e88 cause: 000000000000000f Kernel panic - not syncing: Kernel stack overflow CPU: 1 PID: 205 Comm: bash Not tainted 6.1.0-rc2-00001-g328a1f96f7b9 #34 Hardware name: riscv-virtio,qemu (DT) Call Trace: [<ffffffff80006754>] dump_backtrace+0x30/0x38 [<ffffffff808de798>] show_stack+0x40/0x4c [<ffffffff808ea2a8>] dump_stack_lvl+0x44/0x5c [<ffffffff808ea2d8>] dump_stack+0x18/0x20 [<ffffffff808dec06>] panic+0x126/0x2fe [<ffffffff800065ea>] walk_stackframe+0x0/0xf0 [<ffffffff0163a752>] recursive_loop+0x48/0xc6 [lkdtm] SMP: stopping secondary CPUs ---[ end Kernel panic - not syncing: Kernel stack overflow ]---

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

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Affected Assets

linux
linux kernel
4.15 — 6.5.13 · 6.6 — 6.6.3

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Input validation can reject or constrain data that would otherwise drive unbounded recursive calls.

DoS protection mechanisms limit the resource-exhaustion impact of uncontrolled recursion without eliminating the flaw.

System monitoring can observe anomalous resource consumption that signals runaway recursion after it begins.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly prevent coding errors such as missing recursion limits or termination conditions.

DE.CM-09 partial match
prevents

Runtime monitoring of compute resources can detect excessive consumption caused by uncontrolled recursion.

ID.RA-01 partial match
prevents

Vulnerability identification processes can discover and record uncontrolled recursion flaws before deployment.

PR.IR-04 partial match
prevents

Capacity monitoring and resource provisioning can absorb or limit the impact of runaway recursion.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing in development can detect excessive recursion via static analysis or fuzzing.

prevents

Secure development life cycle requires controls that prevent uncontrolled recursion through design and code review.

prevents

Application security requirements can mandate recursion limits or stack-depth checks.

prevents

Secure system architecture principles include resource-management and input-validation rules that limit recursion.

prevents

Secure coding standards directly prohibit or constrain recursive constructs that could exhaust stack or memory.

finds

Capacity management includes monitoring and limits that mitigate resource exhaustion from runaway recursion.

References