{"id":"CVE-2023-53072","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: use the workqueue to destroy unaccepted sockets\n\nChristoph reported a UaF at token lookup time after having\nrefactored the passive socket initialization part:\n\n …","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: use the workqueue to destroy unaccepted sockets\n\nChristoph reported a UaF at token lookup time after having\nrefactored the passive socket initialization part:\n\n …","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-416"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 5.7, < 6.1.22","linux_kernel >= 6.2, < 6.2.8","linux_kernel = 6.3"],"patched":["linux_kernel 6.2.8"],"published":"2025-05-02","updated":"2026-10-15","sourceUpdated":"2026-10-15T22:17:36.150","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2023-53072","references":[{"url":"https://git.kernel.org/stable/c/2827f099b3fb9a59263c997400e9182f5d423e84","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/804cf487fb0031f3c74755b78d8663333f0ba636","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b6985b9b82954caa53f862d6059d06c0526254f0","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"epss":0.00204,"epssPercentile":0.10308,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-15T21:33:21.799930Z"},"ingestedAt":"2026-10-15T22:48:25.387Z","slug":"CVE-2023-53072","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: use the workqueue to destroy unaccepted sockets\n\nChristoph reported a UaF at token lookup time after having\nrefactored the passive socket initialization part:\n\n  BUG: KASAN: use-after-free in __token_bucket_busy+0x253/0x260\n  Read of size 4 at addr ffff88810698d5b0 by task syz-executor653/3198\n\n  CPU: 1 PID: 3198 Comm: syz-executor653 Not tainted 6.2.0-rc59af4eaa31c1f6c00c8f1e448ed99a45c66340dd5 #6\n  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014\n  Call Trace:\n   <TASK>\n   dump_stack_lvl+0x6e/0x91\n   print_report+0x16a/0x46f\n   kasan_report+0xad/0x130\n   __token_bucket_busy+0x253/0x260\n   mptcp_token_new_connect+0x13d/0x490\n   mptcp_connect+0x4ed/0x860\n   __inet_stream_connect+0x80e/0xd90\n   tcp_sendmsg_fastopen+0x3ce/0x710\n   mptcp_sendmsg+0xff1/0x1a20\n   inet_sendmsg+0x11d/0x140\n   __sys_sendto+0x405/0x490\n   __x64_sys_sendto+0xdc/0x1b0\n   do_syscall_64+0x3b/0x90\n   entry_SYSCALL_64_after_hwframe+0x72/0xdc\n\nWe need to properly clean-up all the paired MPTCP-level\nresources and be sure to release the msk last, even when\nthe unaccepted subflow is destroyed by the TCP internals\nvia inet_child_forget().\n\nWe can re-use the existing MPTCP_WORK_CLOSE_SUBFLOW infra,\nexplicitly checking that for the critical scenario: the\nclosed subflow is the MPC one, the msk is not accepted and\neventually going through full cleanup.\n\nWith such change, __mptcp_destroy_sock() is always called\non msk sockets, even on accepted ones. We don't need anymore\nto transiently drop one sk reference at msk clone time.\n\nPlease note this commit depends on the parent one:\n\n  mptcp: refactor passive socket initialization\n\n## Affected\n\n- `linux_kernel >= 5.7, < 6.1.22`\n- `linux_kernel >= 6.2, < 6.2.8`\n- `linux_kernel = 6.3`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.2.8`","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}