| Summary: |
VUL-0: CVE-2021-47010: kernel: net: Only allow init netns to set default tcp cong to a restricted algo |
| Product: |
[Novell Products] SUSE Security Incidents
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Reporter: |
SMASH SMASH <smash_bz> |
| Component: |
Incidents | Assignee: |
Kernel Bugs <kernel-bugs> |
| Status: |
RESOLVED
FIXED
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QA Contact: |
Security Team bot <security-team> |
| Severity: |
Normal
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| Priority: |
P3 - Medium
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CC: |
meissner, rfrohl
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| Version: |
unspecified | |
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| Target Milestone: |
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| Hardware: |
Other | |
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| OS: |
Other | |
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| URL: |
https://smash.suse.de/issue/395459/
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| Whiteboard: |
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Found By:
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Security Response Team
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Services Priority:
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Business Priority:
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Blocker:
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Marketing QA Status:
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IT Deployment:
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In the Linux kernel, the following vulnerability has been resolved: net: Only allow init netns to set default tcp cong to a restricted algo tcp_set_default_congestion_control() is netns-safe in that it writes to &net->ipv4.tcp_congestion_control, but it also sets ca->flags |= TCP_CONG_NON_RESTRICTED which is not namespaced. This has the unintended side-effect of changing the global net.ipv4.tcp_allowed_congestion_control sysctl, despite the fact that it is read-only: 97684f0970f6 ("net: Make tcp_allowed_congestion_control readonly in non-init netns") Resolve this netns "leak" by only allowing the init netns to set the default algorithm to one that is restricted. This restriction could be removed if tcp_allowed_congestion_control were namespace-ified in the future. This bug was uncovered with https://github.com/JonathonReinhart/linux-netns-sysctl-verify References: http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-47010 https://www.cve.org/CVERecord?id=CVE-2021-47010 https://git.kernel.org/stable/c/6c1ea8bee75df8fe2184a50fcd0f70bf82986f42 https://git.kernel.org/stable/c/8d432592f30fcc34ef5a10aac4887b4897884493 https://git.kernel.org/stable/c/9884f745108f7d25b189bbcd6754e284fb29ab68 https://git.kernel.org/stable/c/992de06308d9a9584d59b96d294ac676f924e437 https://git.kernel.org/stable/c/e7d7bedd507bb732e600403b7a96f9fe48d0ca31 https://git.kernel.org/stable/c/efe1532a6e1a8e3c343d04fff510f0ed80328f9c https://bugzilla.redhat.com/show_bug.cgi?id=2266849