{"id":"CVE-2026-89747","revision":"664d6e46bbb544c18df5dffd29717145","records":[{"revision":"664d6e46bbb544c18df5dffd29717145","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-89747","aliases":[],"title":"tracing: Fix use-after-free in trace_pipe read on sub-buffer order change","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Fix use-after-free in trace_pipe read on sub-buffer order change\n\nWriting to buffer_subbuf_size_kb calls ring_buffer_subbuf_order_set(),\nwhich frees every sub-buffer of the ring buffer, including the reader\npage, and replaces them with newly allocated ones.\n\nReaders of trace_pipe hold pointers into those pages. ring_buffer_peek()\nlooks up an event under cpu_buffer->reader_lock but returns the event\npointer after dropping the lock, and peek_next_entry() then calls\nring_buffer_event_length() and ring_buffer_event_data() on it. If the\nsub-buffer order is changed in that window, the reader dereferences\nfreed memory:\n\n  BUG: KASAN: use-after-free in ring_buffer_peek+0x3e0/0x430\n  Read of size 1 at addr ffff88802a4cf010 by task syz-executor989/6002\n\n  Freed by:\n   free_buffer_page kernel/trace/ring_buffer.c:398 [inline]\n   ring_buffer_subbuf_order_set+0x1325/0x18e0 kernel/trace/ring_buffer.c:7444\n   buffer_subbuf_size_write+0x182/0x280 kernel/trace/trace.c:8221\n\nTake trace_access_lock(RING_BUFFER_ALL_CPUS) around the order change.\nThis is the lock trace_pipe readers already hold across their entire\npeek-and-print loop, so the swap can no longer race with a reader that\nis dereferencing a peeked event.","state":0,"publishedAt":"2026-09-11T19:46:52.268+00:00","modifiedAt":"2026-10-19T08:52:01.177+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/trace.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"f9b94daa542a8d2532f0930f01cd9aec2d19621b\",\n                            \"lessThan\": \"05ebe1e1d7d38c2612bacfefe043a33572ae34cb\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f9b94daa542a8d2532f0930f01cd9aec2d19621b\",\n                            \"lessThan\": \"ddbe921ed16a0ad2d9e09574c3f3aabec7528325\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f9b94daa542a8d2532f0930f01cd9aec2d19621b\",\n                            \"lessThan\": \"7a49d19ff9baaf61217e5ec14199c18bc2d93ee4\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f9b94daa542a8d2532f0930f01cd9aec2d19621b\",\n                            \"lessThan\": \"372f8534244d632ad5118e8a87a11291b01712d3\",\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/trace.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.8\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.8\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.109\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.50\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.4\",\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/05ebe1e1d7d38c2612bacfefe043a33572ae34cb","https://git.kernel.org/stable/c/ddbe921ed16a0ad2d9e09574c3f3aabec7528325","https://git.kernel.org/stable/c/7a49d19ff9baaf61217e5ec14199c18bc2d93ee4","https://git.kernel.org/stable/c/372f8534244d632ad5118e8a87a11291b01712d3"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89747","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-89747","identifiers":["CVE-2026-89747"]},"retained":false,"historicalAffected":[]}],"coverage":[]}