Difference between revisions of "OSSN/OSSN-0099"
Jay Faulkner (talk | contribs) (Created page with "Denial of Service in Ironic under reduced process stack size --- ### Summary ### An unauthenticated malicious user could submit a specially crafted JSON string to certain end...") |
Jay Faulkner (talk | contribs) |
||
| Line 2: | Line 2: | ||
--- | --- | ||
| − | + | === Summary === | |
An unauthenticated malicious user could submit a specially crafted | An unauthenticated malicious user could submit a specially crafted | ||
JSON string to certain endpoints on the API service or the JSON-RPC | JSON string to certain endpoints on the API service or the JSON-RPC | ||
| Line 10: | Line 10: | ||
prior to the initial payload validation. | prior to the initial payload validation. | ||
| − | + | === Affected Services / Software === | |
- ironic: >=32.0.0, <37.0.0 | - ironic: >=32.0.0, <37.0.0 | ||
| − | + | === Discussion === | |
The Ironic project has introduced a customized size check | The Ironic project has introduced a customized size check | ||
middleware which looks for excessive and invalid recursive JSON data | middleware which looks for excessive and invalid recursive JSON data | ||
| Line 19: | Line 19: | ||
based upon the intended patterns of interaction with Ironic. | based upon the intended patterns of interaction with Ironic. | ||
| − | + | === Recommended Actions === | |
Apply the provided Ironic patches. | Apply the provided Ironic patches. | ||
| Line 27: | Line 27: | ||
Several options were added related to permitted JSON body sizing. The defaults | Several options were added related to permitted JSON body sizing. The defaults | ||
should be sufficient for most clouds but can be adjusted: | should be sufficient for most clouds but can be adjusted: | ||
| − | - '[api]/max_json_body_depth', default 25, will reject requests with JSON | + | - |
| + | '[api]/max_json_body_depth', default 25, will reject requests with JSON | ||
documents with more recursion depth than this. | documents with more recursion depth than this. | ||
| − | - '[api]/max_json_body_size', default 1024, is the maximum size, in KiB, the | + | - |
| + | '[api]/max_json_body_size', default 1024, is the maximum size, in KiB, the | ||
API service will accept for any endpoint except the node provision state and | API service will accept for any endpoint except the node provision state and | ||
continue_inspection endpoints. Requests with a larger content-length will | continue_inspection endpoints. Requests with a larger content-length will | ||
receive an HTTP 413 response. | receive an HTTP 413 response. | ||
| − | - '[api]/max_json_body_size_provision', default 65536 (64MiB), is the max size, | + | - |
| + | '[api]/max_json_body_size_provision', default 65536 (64MiB), is the max size, | ||
in KiB, for the node provision state endpoint. The larger default is due to | in KiB, for the node provision state endpoint. The larger default is due to | ||
the need to accomodate configdrives or deploy_steps. | the need to accomodate configdrives or deploy_steps. | ||
| − | - '[api]/max_json_body_size_inspection', default 16384 (16MiB), is the max | + | - |
| + | '[api]/max_json_body_size_inspection', default 16384 (16MiB), is the max | ||
size, in KiB, for the continue_inspection endpoint. The larger default is | size, in KiB, for the continue_inspection endpoint. The larger default is | ||
due to the need to accomodate inspection data from the ramdisk, which can | due to the need to accomodate inspection data from the ramdisk, which can | ||
| Line 46: | Line 50: | ||
services. | services. | ||
| − | + | ==== Patches ==== | |
The following reviews contain the fix for this issue: | The following reviews contain the fix for this issue: | ||
| Line 55: | Line 59: | ||
bugfix/33.0: https://review.opendev.org/c/openstack/ironic/+/991857 | bugfix/33.0: https://review.opendev.org/c/openstack/ironic/+/991857 | ||
| − | + | === Credits === | |
Dmitry Tantsur, Red Hat | Dmitry Tantsur, Red Hat | ||
Tuomo Tanskanen, Ericsson Software Technology | Tuomo Tanskanen, Ericsson Software Technology | ||
Metal3.io Security Team | Metal3.io Security Team | ||
| − | + | === Contacts / References === | |
Authors: | Authors: | ||
- Jay Faulkner, G-Research Open Source Software (GR-OSS) | - Jay Faulkner, G-Research Open Source Software (GR-OSS) | ||
Revision as of 17:03, 5 June 2026
Denial of Service in Ironic under reduced process stack size ---
Contents
Summary
An unauthenticated malicious user could submit a specially crafted JSON string to certain endpoints on the API service or the JSON-RPC endpoint if enabled, and cause a service crash until the service is restarted. This was due to the memory allocation exceeding the stack size of the Python runtime due to Ironic's reduced default stack size prior to the initial payload validation.
Affected Services / Software
- ironic: >=32.0.0, <37.0.0
Discussion
The Ironic project has introduced a customized size check middleware which looks for excessive and invalid recursive JSON data structures while also enforcing path awareness and endpoint size limits based upon the intended patterns of interaction with Ironic.
Recommended Actions
Apply the provided Ironic patches.
Review the newly provided configuration variables defaults in context of your cluster.
Several options were added related to permitted JSON body sizing. The defaults should be sufficient for most clouds but can be adjusted: -
'[api]/max_json_body_depth', default 25, will reject requests with JSON documents with more recursion depth than this.
-
'[api]/max_json_body_size', default 1024, is the maximum size, in KiB, the API service will accept for any endpoint except the node provision state and continue_inspection endpoints. Requests with a larger content-length will receive an HTTP 413 response.
-
'[api]/max_json_body_size_provision', default 65536 (64MiB), is the max size, in KiB, for the node provision state endpoint. The larger default is due to the need to accomodate configdrives or deploy_steps.
-
'[api]/max_json_body_size_inspection', default 16384 (16MiB), is the max size, in KiB, for the continue_inspection endpoint. The larger default is due to the need to accomodate inspection data from the ramdisk, which can include system logs and data larger than normal API requests.
Operators unable or unwilling to patch their Ironic installations can work around the issue by increasing the process stack size by setting the environment variable 'IRONIC_THREAD_STACK_SIZE=8388608' before starting Ironic services.
Patches
The following reviews contain the fix for this issue:
2026.2/hibiscus (master): https://review.opendev.org/c/openstack/ironic/+/991717 2026.1/gazpacho: https://review.opendev.org/c/openstack/ironic/+/991854 2025.2/flamingo: https://review.opendev.org/c/openstack/ironic/+/991858 bugfix/34.0: https://review.opendev.org/c/openstack/ironic/+/991856 bugfix/33.0: https://review.opendev.org/c/openstack/ironic/+/991857
Credits
Dmitry Tantsur, Red Hat Tuomo Tanskanen, Ericsson Software Technology Metal3.io Security Team
Contacts / References
Authors: - Jay Faulkner, G-Research Open Source Software (GR-OSS) - Julia Kreger, Red Hat
This OSSN: https://wiki.openstack.org/wiki/OSSN/OSSN-0099 Original Launchpad bug: https://bugs.launchpad.net/ironic/+bug/2154288 Mailing List : [security-sig] tag on openstack-discuss@lists.openstack.org OpenStack Security : https://security.openstack.org/ CVE: CVE-2026-50589
