{"id":"CVE-2026-99235","title":"tracing: Save the event file instead of the compatible histogram","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Save the event file instead of the compatible histogram\n\ncreate_field_var_hist() creates a histogram on the matched event to\nsupply a field variable, and recor…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < a6165126b1a1b26342b55be6eb6ee23af8756aba","Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < 173914501b97236d7ea7dc2af7f30feddd4e1436","Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < ac815a379644b2ad5008a009a3516ada31b5dd82","Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < 8b307d64a60548e4a74cb746f74d7ed4bd49965e","Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < 7a111ba0d1b74c99bc8f096565dc71945f694254","Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < 3609ada3c12cecfb0ae5ee82ef4f86c5f18a2dea","Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < 9631dbccd3c649b567a5aafffea6b00634183997","Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < 7cafc82e6153f05a221be678cd649d02e06ba909","Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < d5c42664fc094899af9aae5300b27fe8fdb658ef","Linux 4.17"],"published":"2026-11-02","updated":"2026-11-03","sourceUpdated":"2026-11-03T19:13:03.627Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-99235","references":[{"url":"https://git.kernel.org/stable/c/a6165126b1a1b26342b55be6eb6ee23af8756aba"},{"url":"https://git.kernel.org/stable/c/173914501b97236d7ea7dc2af7f30feddd4e1436"},{"url":"https://git.kernel.org/stable/c/ac815a379644b2ad5008a009a3516ada31b5dd82"},{"url":"https://git.kernel.org/stable/c/8b307d64a60548e4a74cb746f74d7ed4bd49965e"},{"url":"https://git.kernel.org/stable/c/7a111ba0d1b74c99bc8f096565dc71945f694254"},{"url":"https://git.kernel.org/stable/c/3609ada3c12cecfb0ae5ee82ef4f86c5f18a2dea"},{"url":"https://git.kernel.org/stable/c/9631dbccd3c649b567a5aafffea6b00634183997"},{"url":"https://git.kernel.org/stable/c/7cafc82e6153f05a221be678cd649d02e06ba909"},{"url":"https://git.kernel.org/stable/c/d5c42664fc094899af9aae5300b27fe8fdb658ef"}],"tags":["cve.org"],"epss":0.00122,"epssPercentile":0.02016,"ingestedAt":"2026-11-05T20:33:06.388Z","slug":"CVE-2026-99235","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Save the event file instead of the compatible histogram\n\ncreate_field_var_hist() creates a histogram on the matched event to\nsupply a field variable, and records it on the target so it can be torn\ndown later:\n\n\thist_data = find_compatible_hist(target_hist_data, file);\n\t...\n\t/* Save the compatible histogram information */\n\tvar_hist->hist_data = hist_data;\n\nhist_data is not the histogram it creates. It is one that was already\nthere, whose keys the new one copies. The saved pointer has a single\nuser, unregister_field_var_hists(), which runs when the target is\nremoved:\n\n\tfile = hist_data->field_var_hists[i]->hist_data->event_file;\n\nfind_compatible_hist() matches on keys alone, so it can pick one with no\nvariables of its own. check_var_refs() then returns false and the user\ncan remove it while the target still points at it:\n\n BUG: KASAN: slab-use-after-free in event_hist_trigger_free+0x2b2/0x320\n Read of size 8 at addr ffff8880093b90e0 by task init/1\n\n Freed by task 1:\n  kfree+0x154/0x420\n  event_hist_trigger_free+0x1d5/0x320\n  event_hist_trigger_parse+0x35f3/0x69e0\n  trigger_process_regex+0x1a6/0x250\n\nSave the event file instead. It is all the dereference ever wanted, and\nit does not go away when the user removes a trigger.\n\n## Affected\n\n- `Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < a6165126b1a1b26342b55be6eb6ee23af8756aba`\n- `Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < 173914501b97236d7ea7dc2af7f30feddd4e1436`\n- `Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < ac815a379644b2ad5008a009a3516ada31b5dd82`\n- `Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < 8b307d64a60548e4a74cb746f74d7ed4bd49965e`\n- `Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < 7a111ba0d1b74c99bc8f096565dc71945f694254`\n- `Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < 3609ada3c12cecfb0ae5ee82ef4f86c5f18a2dea`\n- `Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < 9631dbccd3c649b567a5aafffea6b00634183997`\n- `Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < 7cafc82e6153f05a221be678cd649d02e06ba909`\n- `Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < d5c42664fc094899af9aae5300b27fe8fdb658ef`\n- `Linux 4.17`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}