{"cve":"CVE-2026-89747","nvd":{"published":"2026-09-11T20:20:05.517","modified":"2026-10-19T09:18:17.650","status":"Received","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.","cvss_v4":null,"cvss_v3":{"version":"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},"cwes":[],"references":["https://git.kernel.org/stable/c/05ebe1e1d7d38c2612bacfefe043a33572ae34cb","https://git.kernel.org/stable/c/372f8534244d632ad5118e8a87a11291b01712d3","https://git.kernel.org/stable/c/7a49d19ff9baaf61217e5ec14199c18bc2d93ee4","https://git.kernel.org/stable/c/ddbe921ed16a0ad2d9e09574c3f3aabec7528325"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:53:43.293028046+00:00"},"epss":{"cve":"CVE-2026-89747","score":0.00163,"percentile":0.05463,"date":"2026-10-25"},"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."]}