# CVE-2026-97918: tracing: Undo the registration when enabling the histogram trigger fails

CVE-2026-97918 is fixed in 37 products on 1 platform, first by DEBIAN-CVE-2026-97918, released October 2, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-97918
- Priority: High
- CVSS: 7.8 (Moderate)
- EPSS: 0.0021
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 25, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-97918

## Description

In the Linux kernel, the following vulnerability has been resolved:  tracing: Undo the registration when enabling the histogram trigger fails  Commit 6f86bdeab633 ("tracing: Fix bad hist from corrupting named_triggers list") described how a trigger that is registered but not on file->triggers ends up freed while still on the global named_triggers list, and moved the registration down so that hist_trigger_enable() follows it immediately. One path still gets there. hist_trigger_enable() adds the trigger and takes it straight back out when the event cannot be enabled:  	list_add_tail_rcu(&data->list, &file->triggers);  	update_cond_flag(file);  	if (trace_event_trigger_enable_disable(file, 1) < 0) { 		list_del_rcu(&data->list); 		update_cond_flag(file); 		ret--; 	}  so the list walk in hist_unregister_trigger() matches nothing, test stays NULL, and the ->free() that would call del_named_trigger() is skipped. out_unreg falls through to out_free, which frees the trigger anyway:   BUG: KASAN: slab-use-after-free in find_named_trigger+0xac/0xc0  Read of size 8 at addr ffff8880091d3160 by task init/1   find_named_trigger+0xac/0xc0   hist_register_trigger+0xc1/0xa00   event_hist_trigger_parse+0x3146/0x6af0   event_trigger_write+0xce/0x160  Freed by task 69:   kfree+0x154/0x420   trigger_kthread_fn+0xfd/0x160  Leave the trigger where hist_unregister_trigger() can find it and let that undo the registration, which is the only code that knows all of what cmd_ops->init() took: the named list entry, the hist_pad reference, the reference on the trigger a named histogram is shared with, and the copied cmd_ops. It also pairs the failed trace_event_trigger_enable_disable(), whose sm_ref and buffered event reference are otherwise left behind.  Since ->free() releases trigger_data and, for a trigger that does not share its histogram, hist_data with it, out_unreg can no longer fall through to out_free. For a trigger that does share, hist_register_trigger() has already destroyed the caller's hist_data, so the fall-through was reading freed memory there as well.  Move the enable_timestamps check in hist_unregister_trigger() above the ->free() call for the same reason: hist_data does not outlive it once the trigger being removed is the one that owns it.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | kernel-uek ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-core ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-core ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-core ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-core ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-devel ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-devel ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-core ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-core ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-deprecated ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-deprecated ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-desktop ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-desktop ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-extra ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-extra ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-extra-netfilter ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-extra-netfilter ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-usb ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-usb ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-wireless ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-debug-modules-wireless ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-devel ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-devel ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-doc ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-doc ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-core ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-core ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-deprecated ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-deprecated ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-desktop ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-desktop ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-extra ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-extra ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-extra-netfilter ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-extra-netfilter ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-usb ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-usb ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-wireless ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-modules-wireless ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-tools ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek-tools ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-core ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-core ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-devel ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-devel ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-core ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-core ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-deprecated ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-deprecated ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-desktop ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-desktop ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-extra ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-extra ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-extra-netfilter ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-extra-netfilter ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-usb ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-usb ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-wireless ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | kernel-uek64k-modules-wireless ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.113-1 | [DEBIAN-CVE-2026-97918](https://patchblox.com/security/data/fix/linux/debian-cve-2026-97918.md) | Oct 2, 2026 |
| Linux | linux Debian 14 | 7.2.7-1 | [DEBIAN-CVE-2026-97918](https://patchblox.com/security/data/fix/linux/debian-cve-2026-97918.md) | Oct 2, 2026 |
| Linux | linux-6.12 Debian 12.15 (bookworm) | 6.12.113-1~deb12u1 | [DEBIAN-CVE-2026-97918](https://patchblox.com/security/data/fix/linux/debian-cve-2026-97918.md) | Oct 2, 2026 |

---

Data as of 2026-11-09T01:18:40Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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