{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-97918", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:18:58.202Z", "datePublished": "2026-09-25T10:22:39.162Z", "dateUpdated": "2026-10-21T12:53:37.796Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-21T12:53:37.796Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Undo the registration when enabling the histogram trigger fails\n\nCommit 6f86bdeab633 (\"tracing: Fix bad hist from corrupting named_triggers\nlist\") described how a trigger that is registered but not on file->triggers\nends up freed while still on the global named_triggers list, and moved the\nregistration down so that hist_trigger_enable() follows it immediately. One\npath still gets there. hist_trigger_enable() adds the trigger and takes it\nstraight back out when the event cannot be enabled:\n\n\tlist_add_tail_rcu(&data->list, &file->triggers);\n\n\tupdate_cond_flag(file);\n\n\tif (trace_event_trigger_enable_disable(file, 1) < 0) {\n\t\tlist_del_rcu(&data->list);\n\t\tupdate_cond_flag(file);\n\t\tret--;\n\t}\n\nso the list walk in hist_unregister_trigger() matches nothing, test stays\nNULL, and the ->free() that would call del_named_trigger() is skipped.\nout_unreg falls through to out_free, which frees the trigger anyway:\n\n BUG: KASAN: slab-use-after-free in find_named_trigger+0xac/0xc0\n Read of size 8 at addr ffff8880091d3160 by task init/1\n find_named_trigger+0xac/0xc0\n hist_register_trigger+0xc1/0xa00\n event_hist_trigger_parse+0x3146/0x6af0\n event_trigger_write+0xce/0x160\n Freed by task 69:\n kfree+0x154/0x420\n trigger_kthread_fn+0xfd/0x160\n\nLeave the trigger where hist_unregister_trigger() can find it and let that\nundo the registration, which is the only code that knows all of what\ncmd_ops->init() took: the named list entry, the hist_pad reference, the\nreference on the trigger a named histogram is shared with, and the copied\ncmd_ops. It also pairs the failed trace_event_trigger_enable_disable(),\nwhose sm_ref and buffered event reference are otherwise left behind.\n\nSince ->free() releases trigger_data and, for a trigger that does not share\nits histogram, hist_data with it, out_unreg can no longer fall through to\nout_free. For a trigger that does share, hist_register_trigger() has\nalready destroyed the caller's hist_data, so the fall-through was reading\nfreed memory there as well.\n\nMove the enable_timestamps check in hist_unregister_trigger() above the\n->free() call for the same reason: hist_data does not outlive it once the\ntrigger being removed is the one that owns it." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/trace/trace_events_hist.c" ], "versions": [ { "version": "067fe038e70f6e64960d26a79c4df5f1413d0f13", "lessThan": "880712b6f48103ba3a04b154ff076d45fe86dcec", "status": "affected", "versionType": "git" }, { "version": "067fe038e70f6e64960d26a79c4df5f1413d0f13", "lessThan": "c7ee2d5733574d4694f7c0035e4381f54c1fca27", "status": "affected", "versionType": "git" }, { "version": "067fe038e70f6e64960d26a79c4df5f1413d0f13", "lessThan": "51b07104d563d4be2be34158d3b9d922ca417642", "status": "affected", "versionType": "git" }, { "version": "067fe038e70f6e64960d26a79c4df5f1413d0f13", "lessThan": "bfa6bc11aef93a3d9db0ac9564b734849a9d959b", "status": "affected", "versionType": "git" }, { "version": "067fe038e70f6e64960d26a79c4df5f1413d0f13", "lessThan": "92383cef66791a0c63a2f27755cadbdb2fbf270b", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/trace/trace_events_hist.c" ], "versions": [ { "version": "4.17", "status": "affected" }, { "version": "0", "lessThan": "4.17", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.112", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.53", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.7", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "6.6.160" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "6.12.112" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "6.18.53" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "7.2.7" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.17", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/880712b6f48103ba3a04b154ff076d45fe86dcec" }, { "url": "https://git.kernel.org/stable/c/c7ee2d5733574d4694f7c0035e4381f54c1fca27" }, { "url": "https://git.kernel.org/stable/c/51b07104d563d4be2be34158d3b9d922ca417642" }, { "url": "https://git.kernel.org/stable/c/bfa6bc11aef93a3d9db0ac9564b734849a9d959b" }, { "url": "https://git.kernel.org/stable/c/92383cef66791a0c63a2f27755cadbdb2fbf270b" } ], "title": "tracing: Undo the registration when enabling the histogram trigger fails", "x_generator": { "engine": "bippy-1.2.0" } } } }