Linux Kernel up to 6.1.21/6.2.7 mptcp inet_child_forget initialization

Summaryinfo

A vulnerability classified as problematic was found in Linux Kernel up to 6.1.21/6.2.7. Impacted is the function inet_child_forget of the component mptcp. Such manipulation leads to initialization. This vulnerability is uniquely identified as CVE-2023-53072. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.1.21/6.2.7 and classified as problematic. Affected by this issue is the function inet_child_forget of the component mptcp. The manipulation with an unknown input leads to a initialization vulnerability. Using CWE to declare the problem leads to CWE-665. The product does not initialize or incorrectly initializes a resource, which might leave the resource in an unexpected state when it is accessed or used. The impact remains unknown. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: mptcp: use the workqueue to destroy unaccepted sockets Christoph reported a UaF at token lookup time after having refactored the passive socket initialization part: BUG: KASAN: use-after-free in __token_bucket_busy+0x253/0x260 Read of size 4 at addr ffff88810698d5b0 by task syz-executor653/3198 CPU: 1 PID: 3198 Comm: syz-executor653 Not tainted 6.2.0-rc59af4eaa31c1f6c00c8f1e448ed99a45c66340dd5 #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x6e/0x91 print_report+0x16a/0x46f kasan_report+0xad/0x130 __token_bucket_busy+0x253/0x260 mptcp_token_new_connect+0x13d/0x490 mptcp_connect+0x4ed/0x860 __inet_stream_connect+0x80e/0xd90 tcp_sendmsg_fastopen+0x3ce/0x710 mptcp_sendmsg+0xff1/0x1a20 inet_sendmsg+0x11d/0x140 __sys_sendto+0x405/0x490 __x64_sys_sendto+0xdc/0x1b0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc We need to properly clean-up all the paired MPTCP-level resources and be sure to release the msk last, even when the unaccepted subflow is destroyed by the TCP internals via inet_child_forget(). We can re-use the existing MPTCP_WORK_CLOSE_SUBFLOW infra, explicitly checking that for the critical scenario: the closed subflow is the MPC one, the msk is not accepted and eventually going through full cleanup. With such change, __mptcp_destroy_sock() is always called on msk sockets, even on accepted ones. We don't need anymore to transiently drop one sk reference at msk clone time. Please note this commit depends on the parent one: mptcp: refactor passive socket initialization

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2023-53072 since 05/02/2025. The exploitation is known to be difficult. Technical details are known, but there is no available exploit.

Upgrading to version 6.1.22 or 6.2.8 eliminates this vulnerability. Applying the patch 2827f099b3fb9a59263c997400e9182f5d423e84/804cf487fb0031f3c74755b78d8663333f0ba636/b6985b9b82954caa53f862d6059d06c0526254f0 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.1.0
• 6.1.1
• 6.1.2
• 6.1.3
• 6.1.4
• 6.1.5
• 6.1.6
• 6.1.7
• 6.1.8
• 6.1.9
• 6.1.10
• 6.1.11
• 6.1.12
• 6.1.13
• 6.1.14
• 6.1.15
• 6.1.16
• 6.1.17
• 6.1.18
• 6.1.19
• 6.1.20
• 6.1.21
• 6.2.0
• 6.2.1
• 6.2.2
• 6.2.3
• 6.2.4
• 6.2.5
• 6.2.6
• 6.2.7

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

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