{"cve":"CVE-2023-53490","nvd":{"published":"2025-10-01T12:15:52.107","modified":"2026-08-04T10:19:08.740","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: fix disconnect vs accept race\n\nDespite commit 0ad529d9fd2b (\"mptcp: fix possible divide by zero in\nrecvmsg()\"), the mptcp protocol is still prone to a race between\ndisconnect() (or shutdown) and accept.\n\nThe root cause is that the mentioned commit checks the msk-level\nflag, but mptcp_stream_accept() does acquire the msk-level lock,\nas it can rely directly on the first subflow lock.\n\nAs reported by Christoph than can lead to a race where an msk\nsocket is accepted after that mptcp_subflow_queue_clean() releases\nthe listener socket lock and just before it takes destructive\nactions leading to the following splat:\n\nBUG: kernel NULL pointer dereference, address: 0000000000000012\nPGD 5a4ca067 P4D 5a4ca067 PUD 37d4c067 PMD 0\nOops: 0000 [#1] PREEMPT SMP\nCPU: 2 PID: 10955 Comm: syz-executor.5 Not tainted 6.5.0-rc1-gdc7b257ee5dd #37\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014\nRIP: 0010:mptcp_stream_accept+0x1ee/0x2f0 include/net/inet_sock.h:330\nCode: 0a 09 00 48 8b 1b 4c 39 e3 74 07 e8 bc 7c 7f fe eb a1 e8 b5 7c 7f fe 4c 8b 6c 24 08 eb 05 e8 a9 7c 7f fe 49 8b 85 d8 09 00 00 <0f> b6 40 12 88 44 24 07 0f b6 6c 24 07 bf 07 00 00 00 89 ee e8 89\nRSP: 0018:ffffc90000d07dc0 EFLAGS: 00010293\nRAX: 0000000000000000 RBX: ffff888037e8d020 RCX: ffff88803b093300\nRDX: 0000000000000000 RSI: ffffffff833822c5 RDI: ffffffff8333896a\nRBP: 0000607f82031520 R08: ffff88803b093300 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000003e83 R12: ffff888037e8d020\nR13: ffff888037e8c680 R14: ffff888009af7900 R15: ffff888009af6880\nFS:  00007fc26d708640(0000) GS:ffff88807dd00000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 0000000000000012 CR3: 0000000066bc5001 CR4: 0000000000370ee0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\nCall Trace:\n <TASK>\n do_accept+0x1ae/0x260 net/socket.c:1872\n __sys_accept4+0x9b/0x110 net/socket.c:1913\n __do_sys_accept4 net/socket.c:1954 [inline]\n __se_sys_accept4 net/socket.c:1951 [inline]\n __x64_sys_accept4+0x20/0x30 net/socket.c:1951\n do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n do_syscall_64+0x47/0xa0 arch/x86/entry/common.c:80\n entry_SYSCALL_64_after_hwframe+0x6e/0xd8\n\nAddress the issue by temporary removing the pending request socket\nfrom the accept queue, so that racing accept() can't touch them.\n\nAfter depleting the msk - the ssk still exists, as plain TCP sockets,\nre-insert them into the accept queue, so that later inet_csk_listen_stop()\nwill complete the tcp socket disposal.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","score":4.7},"cwes":["CWE-362"],"references":["https://git.kernel.org/stable/c/511b90e39250135a7f900f1c3afbce25543018a2","https://git.kernel.org/stable/c/b2b4c84eb7149f34c0f25f17042d095ba5357d68","https://git.kernel.org/stable/c/ded9f5551ce5cafa3c41c794428c27a0d0a00542"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:11:26.888974865+00:00"},"epss":{"cve":"CVE-2023-53490","score":0.0012,"percentile":0.01797,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}