{"id":"CVE-2026-89902","revision":"6e199f3b895b4b3e9137f29a8b277363","records":[{"revision":"6e199f3b895b4b3e9137f29a8b277363","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-89902","aliases":[],"title":"LoongArch: Avoid preempt count underflow without probe","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nLoongArch: Avoid preempt count underflow without probe\n\nLoongArch uses break 11 for the breakpoint placed after an instruction\nthat Kprobes executes out of line. Since userspace can issue the same\nbreak instruction, do_bp() can reach kprobe_singlestep_handler() when\nthere is no current probe.\n\nThe handler actually returns false in this case, but it first calls\npreempt_enable_no_resched(). The corresponding preempt_disable() is done\nby kprobe_breakpoint_handler() on a real Kprobe hit, so it has not run\nhere. As a result, an ordinary userspace breakpoint (code 11) underflows\nthe current task's preempt count.\n\nThis also makes in_interrupt() return true until the task schedules. One\nvisible consequence is the socket cgroup attribution: cgroup_sk_alloc()\ntreats the allocation as interrupt context and assigns the socket to the\nroot cgroup. A socket opened from the SIGTRAP handler can then avoid a\nBPF_CGROUP_INET_SOCK_CREATE policy attached to the task's own cgroup.\n\nReturn as soon as kprobe_running() reports no active probe.\n\nThe same check has appeared in [PATCH v10 2/4] of the original LoongArch\nKprobes series, but was dropped before the feature reached mainline.","state":0,"publishedAt":"2026-09-16T10:32:01.655+00:00","modifiedAt":"2026-10-19T08:54:35.1+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"arch/loongarch/kernel/kprobes.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6d4cc40fb5f58147defc6c0e9d86e6232fe31616\",\n                            \"lessThan\": \"ff40e597d5d98c0c45a4d09df8177202fac9520e\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"6d4cc40fb5f58147defc6c0e9d86e6232fe31616\",\n                            \"lessThan\": \"a1cb727fa27c2d9c7859729cd90db7bc0f46957f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"6d4cc40fb5f58147defc6c0e9d86e6232fe31616\",\n                            \"lessThan\": \"76395109a051b53860faaec96522ef08ae9e8e27\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"6d4cc40fb5f58147defc6c0e9d86e6232fe31616\",\n                            \"lessThan\": \"c4357ebeee63cb8da1446fc936573a34e68b0f71\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"6d4cc40fb5f58147defc6c0e9d86e6232fe31616\",\n                            \"lessThan\": \"72ce4b24676e8b3b75376c4c559dd81c1ac52d5a\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"arch/loongarch/kernel/kprobes.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.3\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.3\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.157\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.110\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.51\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.5\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/ff40e597d5d98c0c45a4d09df8177202fac9520e","https://git.kernel.org/stable/c/a1cb727fa27c2d9c7859729cd90db7bc0f46957f","https://git.kernel.org/stable/c/76395109a051b53860faaec96522ef08ae9e8e27","https://git.kernel.org/stable/c/c4357ebeee63cb8da1446fc936573a34e68b0f71","https://git.kernel.org/stable/c/72ce4b24676e8b3b75376c4c559dd81c1ac52d5a"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89902","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-89902","identifiers":["CVE-2026-89902"]},"retained":false,"historicalAffected":[]}],"coverage":[]}