CVE-2023-4194: Kernel: tap: tap_open(): correctly initialize socket uid next fix of i_uid to current_fsuid
First published: Sun Aug 06 2023(Updated: )
A flaw found in the Linux Kernel. The tun/tap sockets have their socket UID hardcoded to 0 due to a type confusion in their initialization function. While it will be often correct, as tuntap devices require CAP_NET_ADMIN, it may not always be the case, e.g., a non-root user only having that capability. This would make tun/tap sockets being incorrectly treated in filtering/routing decisions, possibly bypassing network filters. The original fix for the <a href="https://access.redhat.com/security/cve/CVE-2023-1076">CVE-2023-1076</a> was incorrect. The problem is that the following upstream commits (that were fix for the <a href="https://access.redhat.com/security/cve/CVE-2023-1076">CVE-2023-1076</a>) - a096ccca6e50 ("tun: tun_chr_open(): correctly initialize socket uid"), - 66b2c338adce ("tap: tap_open(): correctly initialize socket uid"), pass "inode->i_uid" to sock_init_data_uid() as the last parameter and that turns out to be entirely bogus. References: <a href="https://lore.kernel.org/all/20230731164237.48365-1-lersek@redhat.com/">https://lore.kernel.org/all/20230731164237.48365-1-lersek@redhat.com/</a> <a href="https://lore.kernel.org/all/20230731164237.48365-2-lersek@redhat.com/">https://lore.kernel.org/all/20230731164237.48365-2-lersek@redhat.com/</a> <a href="https://lore.kernel.org/all/20230731164237.48365-3-lersek@redhat.com/">https://lore.kernel.org/all/20230731164237.48365-3-lersek@redhat.com/</a>
Credit: secalert@redhat.com secalert@redhat.com secalert@redhat.com
| Affected Software | Affected Version | How to fix |
|---|---|---|
| Linux Linux kernel | <=6.4 | |
| Linux Linux kernel | =6.5-rc1 | |
| Linux Linux kernel | =6.5-rc2 | |
| Linux Linux kernel | =6.5-rc3 | |
| Linux Linux kernel | =6.5-rc4 | |
| Redhat Enterprise Linux | =8.0 | |
| Redhat Enterprise Linux | =9.0 | |
| Fedoraproject Fedora | =37 | |
| Fedoraproject Fedora | =38 | |
| redhat/kernel | <6.5 | 6.5 |
| Debian Debian Linux | =10.0 | |
| Debian Debian Linux | =11.0 | |
| Debian Debian Linux | =12.0 | |
| debian/linux | 5.10.223-1 5.10.226-1 6.1.115-1 6.1.119-1 6.12.5-1 |
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Reference Links
- https://access.redhat.com/security/cve/CVE-2023-4194
- https://bugzilla.redhat.com/show_bug.cgi?id=2229498
- https://lists.debian.org/debian-lts-announce/2023/10/msg00027.html
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/344H6HO6SSC4KT7PDFXSDIXKMKHISSGF/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/3TYLSJ2SAI7RF56ZLQ5CQWCJLVJSD73Q/
- https://lore.kernel.org/all/20230731164237.48365-1-lersek@redhat.com/
- https://lore.kernel.org/all/20230731164237.48365-2-lersek@redhat.com/
- https://lore.kernel.org/all/20230731164237.48365-3-lersek@redhat.com/
- https://www.debian.org/security/2023/dsa-5480
- https://www.debian.org/security/2023/dsa-5492
- https://security.netapp.com/advisory/ntap-20231027-0002/
- https://access.redhat.com/errata/RHSA-2023:6583
- https://launchpad.net/bugs/cve/CVE-2023-4194
- https://access.redhat.com/security/cve/CVE-2023-1076
- https://bugzilla.redhat.com/show_bug.cgi/show_bug.cgi?id=2229499
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-4194
- https://nvd.nist.gov/vuln/detail/CVE-2023-4194
- https://security-tracker.debian.org/tracker/CVE-2023-4194
- https://ubuntu.com/security/CVE-2023-4194
- https://git.kernel.org/linus/9bc3047374d5bec163e83e743709e23753376f0c
- https://git.kernel.org/linus/5c9241f3ceab3257abe2923a59950db0dc8bb737
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