{"id":"CVE-2026-74601","revision":"af99dd153bd844c68b42653c5bf066c2","records":[{"revision":"af99dd153bd844c68b42653c5bf066c2","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-74601","aliases":[],"title":"ring-buffer: Use current_context for safe per-CPU buffer swap","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nring-buffer: Use current_context for safe per-CPU buffer swap\n\nThe ring_buffer_swap_cpu() function currently checks the per-CPU\ncommitting counter to determine if a buffer is actively being written to\nbefore performing the swap. However, there exists a race window where\nthis check can be bypassed:\n\n    ring_buffer_lock_reserve\n        cpu_buffer = buffer->buffers[cpu];       // cpu_buffer_a\n        rb_reserve_next_event\n            rb_start_commit // inc committing\n            if (unlikely(READ_ONCE(cpu_buffer->buffer) != buffer)) {...}\n            __rb_reserve_next\n                rb_move_tail\n                    rb_end_commit(cpu_buffer);   // dec committing => 0\n                    /* interrupt hits here, successfully swaps! */\n                    local_inc(&cpu_buffer->committing);\n\n    ring_buffer_unlock_commit\n        cpu_buffer = buffer->buffers[cpu];      // cpu_buffer_b\n        rb_commit\n            rb_end_commit\n            RB_WARN_ON(cpu_buffer, !local_read(&cpu_buffer->committing))\n                                                // triggers warning\n\nThe committing counter can temporarily drop to 0 during a single write\noperation (within rb_move_tail), creating a window where swap can\nsucceed even though the write is still in progress. This leads to\ninconsistent buffer state and triggers the RB_WARN_ON in rb_commit().\n\nReplace the committing counter check with current_context checks, which\nare set at the entry of ring_buffer_lock_reserve() and remain valid\nthroughout the entire write operation, providing a reliable indicator of\nbuffer busy state during swap.","state":0,"publishedAt":"2026-08-22T15:31:50.092+00:00","modifiedAt":"2026-10-16T19:06:00.447+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                        \"kernel/trace/ring_buffer.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"4239c38fe0b3847e1e6d962c74b41b08ba0e2990\",\n                            \"lessThan\": \"26662bc8fced1d668fa1aa146eda085bfc67bd0b\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"4239c38fe0b3847e1e6d962c74b41b08ba0e2990\",\n                            \"lessThan\": \"6b524e6b234e45c7f5f90d13b042c6f57f80105c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"4239c38fe0b3847e1e6d962c74b41b08ba0e2990\",\n                            \"lessThan\": \"597f279b7b4a06412e3d965e98cc36e181cdbede\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"4239c38fe0b3847e1e6d962c74b41b08ba0e2990\",\n                            \"lessThan\": \"22709117d9ae95e52673685f98caac7c356a8227\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"4239c38fe0b3847e1e6d962c74b41b08ba0e2990\",\n                            \"lessThan\": \"ad7e10c7ea89af45ac1bf1814855d45da472703d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"4239c38fe0b3847e1e6d962c74b41b08ba0e2990\",\n                            \"lessThan\": \"5b926fb04cb9ef3156dcf88c69a59d3d1a1c4f9f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"4239c38fe0b3847e1e6d962c74b41b08ba0e2990\",\n                            \"lessThan\": \"5e6e2a18c20e88167d414f666032792e8bf19b80\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"4239c38fe0b3847e1e6d962c74b41b08ba0e2990\",\n                            \"lessThan\": \"f27bdc43077e4fcb5557dfc315ee8d91e741f483\",\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                        \"kernel/trace/ring_buffer.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"4.5\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"4.5\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.266\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.217\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.184\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.153\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.105\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.45\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.9\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2\",\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/26662bc8fced1d668fa1aa146eda085bfc67bd0b","https://git.kernel.org/stable/c/6b524e6b234e45c7f5f90d13b042c6f57f80105c","https://git.kernel.org/stable/c/597f279b7b4a06412e3d965e98cc36e181cdbede","https://git.kernel.org/stable/c/22709117d9ae95e52673685f98caac7c356a8227","https://git.kernel.org/stable/c/ad7e10c7ea89af45ac1bf1814855d45da472703d","https://git.kernel.org/stable/c/5b926fb04cb9ef3156dcf88c69a59d3d1a1c4f9f","https://git.kernel.org/stable/c/5e6e2a18c20e88167d414f666032792e8bf19b80","https://git.kernel.org/stable/c/f27bdc43077e4fcb5557dfc315ee8d91e741f483"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-74601","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-74601","identifiers":["CVE-2026-74601"]},"retained":false,"historicalAffected":[]}],"coverage":[]}