bpf: Prevent tail call between progs attached to different hooks

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2024-50063
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2024-10-21 20:15:18 UTC
Updated2026-07-14 13:17:11 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: bpf: Prevent tail call between progs attached to different hooks bpf progs can be attached to kernel functions, and the attached functions can take different parameters or return different return values. If prog attached to one kernel function tail calls prog attached to another kernel function, the ctx access or return value verification could be bypassed. For example, if prog1 is attached to func1 which takes only 1 parameter and prog2 is attached to func2 which takes two parameters. Since verifier assumes the bpf ctx passed to prog2 is constructed based on func2's prototype, verifier allows prog2 to access the second parameter from the bpf ctx passed to it. The problem is that verifier does not prevent prog1 from passing its bpf ctx to prog2 via tail call. In this case, the bpf ctx passed to prog2 is constructed from func1 instead of func2, that is, the assumption for ctx access verification is bypassed. Another example, if BPF LSM prog1 is attached to hook file_alloc_security, and BPF LSM prog2 is attached to hook bpf_lsm_audit_rule_known. Verifier knows the return value rules for these two hooks, e.g. it is legal for bpf_lsm_audit_rule_known to return positive number 1, and it is illegal for file_alloc_security to return positive number. So verifier allows prog2 to return positive number 1, but does not allow prog1 to return positive number. The problem is that verifier does not prevent prog1 from calling prog2 via tail call. In this case, prog2's return value 1 will be used as the return value for prog1's hook file_alloc_security. That is, the return value rule is bypassed. This patch adds restriction for tail call to prevent such bypasses.

Risk And Classification

Primary CVSS: v3.1 7.8 HIGH from [email protected]

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Problem Types: NVD-CWE-noinfo

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Operating System Debian Debian Linux 11.0 All All All
Operating System Linux Linux Kernel All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected f1b9509c2fb0ef4db8d22dac9aef8e856a5d81f6 d9a807fb7cbfad4328824186e2e4bee28f72169b git Not specified
CNA Linux Linux affected f1b9509c2fb0ef4db8d22dac9aef8e856a5d81f6 5d5e3b4cbe8ee16b7bf96fd73a421c92a9da3ca1 git Not specified
CNA Linux Linux affected f1b9509c2fb0ef4db8d22dac9aef8e856a5d81f6 88c2a10e6c176c2860cd0659f4c0e9d20b3f64d1 git Not specified
CNA Linux Linux affected f1b9509c2fb0ef4db8d22dac9aef8e856a5d81f6 28ead3eaabc16ecc907cfb71876da028080f6356 git Not specified
CNA Linux Linux affected 5.5 Not specified
CNA Linux Linux unaffected 5.5 semver Not specified
CNA Linux Linux unaffected 6.1.135 6.1.* semver Not specified
CNA Linux Linux unaffected 6.6.57 6.6.* semver Not specified
CNA Linux Linux unaffected 6.11.4 6.11.* semver Not specified
CNA Linux Linux unaffected 6.12 * original_commit_for_fix Not specified
ADP Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP affected V3.1.6 * custom Not specified
ADP Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP affected V3.1.6 * custom Not specified
ADP Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP affected V3.1.6 * custom Not specified
ADP Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP affected V3.1.6 * custom Not specified
ADP Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP affected V3.1.6 * custom Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/5d5e3b4cbe8ee16b7bf96fd73a421c92a9da3ca1 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/88c2a10e6c176c2860cd0659f4c0e9d20b3f64d1 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
cert-portal.siemens.com/productcert/html/ssa-019113.html 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e cert-portal.siemens.com
git.kernel.org/stable/c/28ead3eaabc16ecc907cfb71876da028080f6356 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
lists.debian.org/debian-lts-announce/2025/05/msg00045.html af854a3a-2127-422b-91ae-364da2661108 lists.debian.org Mailing List, Third Party Advisory
git.kernel.org/stable/c/d9a807fb7cbfad4328824186e2e4bee28f72169b 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
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