{ "schema_version": "1.6.1", "id": "RPI-CVE-2026-99237", "modified": "2026-11-03T05:30:01Z", "upstream": [ "CVE-2026-99237" ], "published": "2026-11-02T15:14:24Z", "summary": "tracing: Hold trace_types_lock when resetting last boot data from readers", "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Hold trace_types_lock when resetting last boot data from readers\n\nupdate_last_data_if_empty() is called from tracing_open() with O_TRUNC,\ntracing_read_pipe() and tracing_buffers_read() without trace_types_lock.\nTwo readers can both pass the LAST_BOOT test and free module_delta\ntwice, and a module notifier can update module_delta while it is being\nfreed.\n\nTake trace_types_lock in those paths and keep the callers that already\nhold it on an unlocked variant.", "severity": [ { "type": "CVSS_V3", "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H" } ], "affected": [ { "package": { "ecosystem": "Raspberry Pi OS:13", "name": "linux" }, "versions": [ "1:6.18.29-1+rpt1", "1:6.18.33-1+rpt1", "1:6.18.34-1+rpt1", "1:6.18.39-1+rpt1", "1:6.18.50-1+rpt1" ], "ecosystem_specific": { "binaries": [ { "binary_name": "linux-image-6.18.29+rpt-rpi-2712", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v6", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v7", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v8", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v8-rt", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-2712", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v6", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v7", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v8", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v8-rt", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-2712", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v6", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v7", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v8", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v8-rt", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-2712", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v6", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v7", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v8", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v8-rt", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-2712", "binary_version": "1:6.18.50-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-v6", "binary_version": "1:6.18.50-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-v7", "binary_version": "1:6.18.50-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-v8", "binary_version": "1:6.18.50-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-v8-rt", "binary_version": "1:6.18.50-1+rpt1" } ] }, "database_specific": { "per_version": { "1:6.18.29-1+rpt1": { "linux_commit": "66318c5b5cd8145a662303af12ed39ac07eb27cc", "upstream_version": "6.18.29", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.60" }, "1:6.18.33-1+rpt1": { "linux_commit": "95b85bebbedcaedfa7ca79116ed38b7376fba412", "upstream_version": "6.18.33", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.60" }, "1:6.18.34-1+rpt1": { "linux_commit": "c8c7494100e99ee05b11aaa4f0588a223a63d1af", "upstream_version": "6.18.34", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.60" }, "1:6.18.39-1+rpt1": { "linux_commit": "60ea684a8ace97bb0db1a16e20753bdd6ab371ff", "upstream_version": "6.18.39", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.60" }, "1:6.18.50-1+rpt1": { "linux_commit": "cff533aec2fa601846766b32ff57204e0a61bed7", "upstream_version": "6.18.50", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.60" } } } } ], "references": [ { "type": "ADVISORY", "url": "https://www.cve.org/CVERecord?id=CVE-2026-99237" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/92b69f6db640dadc0851762ee2e12db99f083cad" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/d6d991afe775ab7fcf89523a2502b7ca3be56ffd" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/1f06cfe0b60a878619d1d8efe1cd0f515b7dc2aa" } ], "database_specific": { "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git", "upstream_modified": "2026-11-02T16:03:24Z", "severity": { "source": "kernel CNA", "cvss_v3_score": 7.8, "cvss_v3_severity": "High", "scenario": "AV:L - Reached only via local tracefs on a last-boot instance: tracing_open() with O_TRUNC on instances//trace, tracing_read_pipe() on trace_pipe, and tracing_buffers_read() on per_cpu/cpuN/trace_pipe_raw all call update_last_data_if_empty() without trace_types_lock. No remote protocol supplies the trigger.\nAC:L - The attacker controls both sides. Two threads can open() the last-boot instance's trace with O_TRUNC, or drain the buffer then race tracing_buffers_read() on two trace_pipe_raw fds; both call update_last_data_if_empty() unlocked so each can pass TRACE_ARRAY_FL_LAST_BOOT and kfree_rcu() the same module_delta. The module-notifier race is not required.\nPR:L - tracing_check_open_get_tr() checks only LOCKDOWN_TRACEFS and tracing_disabled, not capable(). trace is TRACE_MODE_WRITE (0640) and trace_pipe/trace_pipe_raw are TRACE_MODE_READ (0440). tracefs uid=/gid= mounts delegate those inodes to a non-root tracing group on Android/Perfetto and embedded systems that use reserve_mem persistent instances.\nUI:N - The attacker opens, truncates, and reads their own last-boot instance descriptors (tracing_open(O_TRUNC) or tracing_buffers_read()). No other user must mount media, enable tracing, or consume the buffer first.\nS:U - The double-free of tr->module_delta is in the host kernel heap (update_last_data() kfree_rcu() racing make_mod_delta()). It can escalate locally but does not cross a VM, IOMMU, or sandbox boundary.\nC:H - Two update_last_data() callers can both READ_ONCE(tr->module_delta) then kfree_rcu() it, and make_mod_delta() still indexes module_delta->delta[] after the free. That slab use-after-free of the flex-array object is an arbitrary kernel-memory read primitive.\nI:H - The same double kfree_rcu(module_delta) plus make_mod_delta() writing module_delta->delta[i] after the object is freed is a heap use-after-free write. Reclaiming that slab yields an arbitrary kernel write and control-flow hijack, not merely a crash.\nA:H - Double-free of module_delta, or make_mod_delta() using it after WRITE_ONCE(tr->module_delta, NULL), oopses or panics the kernel. The attacker retriggers that crash through the unlocked tracing_open(O_TRUNC) or tracing_buffers_read() paths." } } }