{"id":"CVE-2026-74391","title":"tracing: Bound synthetic-field strings with seq_buf","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Bound synthetic-field strings with seq_buf\n\nThe synthetic field helpers build a prefixed synthetic variable name and\na generated hist command in fixed MAX_FILT…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < 9f8ef2e1e95a42044e614b0a5277e3f53f545135","Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < 0c584c27f6649a93ec12061cc779a4bd8f7c1434","Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < 88b901fdc1662b131ff908cbd017333b61e7acc8","Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < baa333b2700a7fa3529d504529c8c10060fd687c","Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < cf334620036ad2250e008c7e7bb6646a3938b7b0","Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < f07883450eb14d1cf020b55d9f3a7ec5683bcd26","Linux 4.17"],"published":"2026-08-15","updated":"2026-10-30","sourceUpdated":"2026-10-30T12:29:55.331Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-74391","references":[{"url":"https://git.kernel.org/stable/c/9f8ef2e1e95a42044e614b0a5277e3f53f545135"},{"url":"https://git.kernel.org/stable/c/0c584c27f6649a93ec12061cc779a4bd8f7c1434"},{"url":"https://git.kernel.org/stable/c/88b901fdc1662b131ff908cbd017333b61e7acc8"},{"url":"https://git.kernel.org/stable/c/baa333b2700a7fa3529d504529c8c10060fd687c"},{"url":"https://git.kernel.org/stable/c/cf334620036ad2250e008c7e7bb6646a3938b7b0"},{"url":"https://git.kernel.org/stable/c/f07883450eb14d1cf020b55d9f3a7ec5683bcd26"}],"tags":["cve.org"],"epss":0.00173,"epssPercentile":0.06789,"ingestedAt":"2026-11-05T15:02:32.548Z","slug":"CVE-2026-74391","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Bound synthetic-field strings with seq_buf\n\nThe synthetic field helpers build a prefixed synthetic variable name and\na generated hist command in fixed MAX_FILTER_STR_VAL buffers. The\ncurrent code appends those strings with raw strcat(), so long key lists,\nfield names, or saved filters can run past the end of the staging\nbuffers.\n\nBuild both strings with seq_buf and propagate -E2BIG if either the\nsynthetic variable name or the generated command exceeds\nMAX_FILTER_STR_VAL. This keeps the existing tracing-side limit while\nusing the helper intended for bounded command construction.\n\n[ sdr: Moved struct seq_buf *s for upside-down x-mas tree formatting ]\n\n## Affected\n\n- `Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < 9f8ef2e1e95a42044e614b0a5277e3f53f545135`\n- `Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < 0c584c27f6649a93ec12061cc779a4bd8f7c1434`\n- `Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < 88b901fdc1662b131ff908cbd017333b61e7acc8`\n- `Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < baa333b2700a7fa3529d504529c8c10060fd687c`\n- `Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < cf334620036ad2250e008c7e7bb6646a3938b7b0`\n- `Linux >= 02205a6752f223779a1b0e9e8ffacbea6e717851 < f07883450eb14d1cf020b55d9f3a7ec5683bcd26`\n- `Linux 4.17`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}