{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2023-53478", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2023-53478", "idYear": 2023, "status": "PUBLISHED", "publishedAt": "2025-10-01T11:42:47.185Z", "updatedAt": "2026-08-05T09:14:16.799Z", "importedAt": "2026-10-24T01:57:03.413Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "tracing/synthetic: Fix races on freeing last_cmd", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\ntracing/synthetic: Fix races on freeing last_cmd\n\nCurrently, the \"last_cmd\" variable can be accessed by multiple processes\nasynchronously when multiple users manipulate synthetic_events node\nat the same time, it could lead to use-after-free or double-free.\n\nThis patch add \"lastcmd_mutex\" to prevent \"last_cmd\" from being accessed\nasynchronously.\n\n================================================================\n\nIt's easy to reproduce in the KASAN environment by running the two\nscripts below in different shells.\n\nscript 1:\n while :\n do\n echo -n -e '\\x88' > /sys/kernel/tracing/synthetic_events\n done\n\nscript 2:\n while :\n do\n echo -n -e '\\xb0' > /sys/kernel/tracing/synthetic_events\n done\n\n================================================================\ndouble-free scenario:\n\n process A process B\n------------------- ---------------\n1.kstrdup last_cmd\n 2.free last_cmd\n3.free last_cmd(double-free)\n\n================================================================\nuse-after-free scenario:\n\n process A process B\n------------------- ---------------\n1.kstrdup last_cmd\n 2.free last_cmd\n3.tracing_log_err(use-after-free)\n\n================================================================\n\nAppendix 1. KASAN report double-free:\n\nBUG: KASAN: double-free in kfree+0xdc/0x1d4\nFree of addr ***** by task sh/4879\nCall trace:\n ...\n kfree+0xdc/0x1d4\n create_or_delete_synth_event+0x60/0x1e8\n trace_parse_run_command+0x2bc/0x4b8\n synth_events_write+0x20/0x30\n vfs_write+0x200/0x830\n ...\n\nAllocated by task 4879:\n ...\n kstrdup+0x5c/0x98\n create_or_delete_synth_event+0x6c/0x1e8\n trace_parse_run_command+0x2bc/0x4b8\n synth_events_write+0x20/0x30\n vfs_write+0x200/0x830\n ...\n\nFreed by task 5464:\n ...\n kfree+0xdc/0x1d4\n create_or_delete_synth_event+0x60/0x1e8\n trace_parse_run_command+0x2bc/0x4b8\n synth_events_write+0x20/0x30\n vfs_write+0x200/0x830\n ...\n\n================================================================\nAppendix 2. KASAN report use-after-free:\n\nBUG: KASAN: use-after-free in strlen+0x5c/0x7c\nRead of size 1 at addr ***** by task sh/5483\nsh: CPU: 7 PID: 5483 Comm: sh\n ...\n __asan_report_load1_noabort+0x34/0x44\n strlen+0x5c/0x7c\n tracing_log_err+0x60/0x444\n create_or_delete_synth_event+0xc4/0x204\n trace_parse_run_command+0x2bc/0x4b8\n synth_events_write+0x20/0x30\n vfs_write+0x200/0x830\n ...\n\nAllocated by task 5483:\n ...\n kstrdup+0x5c/0x98\n create_or_delete_synth_event+0x80/0x204\n trace_parse_run_command+0x2bc/0x4b8\n synth_events_write+0x20/0x30\n vfs_write+0x200/0x830\n ...\n\nFreed by task 5480:\n ...\n kfree+0xdc/0x1d4\n create_or_delete_synth_event+0x74/0x204\n trace_parse_run_command+0x2bc/0x4b8\n synth_events_write+0x20/0x30\n vfs_write+0x200/0x830\n ...", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "27c888da9867725784bad3d6455d6e53b425fa2b", "status": "affected", "versionType": "git", "lessThan": "9fe183f659a2704255e5d84f6ae308c234a113ec" }, { "version": "27c888da9867725784bad3d6455d6e53b425fa2b", "status": "affected", "versionType": "git", "lessThan": "8826d9e7bd51e7656f78baa4472e8e2f5e7069f0" }, { "version": "27c888da9867725784bad3d6455d6e53b425fa2b", "status": "affected", "versionType": "git", "lessThan": "4ccf11c4e8a8e051499d53a12f502196c97a758e" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "5.18", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "5.18" }, { "version": "6.1.24", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.1.*" }, { "version": "6.2.11", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.2.*" }, { "version": "6.3", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }