{ "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-2025-40042", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2025-40042", "idYear": 2025, "status": "PUBLISHED", "publishedAt": "2025-10-28T11:48:21.638Z", "updatedAt": "2026-05-11T21:41:21.533Z", "importedAt": "2026-10-24T01:57:34.152Z", "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: Fix race condition in kprobe initialization causing NULL pointer dereference", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Fix race condition in kprobe initialization causing NULL pointer dereference\n\nThere is a critical race condition in kprobe initialization that can lead to\nNULL pointer dereference and kernel crash.\n\n[1135630.084782] Unable to handle kernel paging request at virtual address 0000710a04630000\n...\n[1135630.260314] pstate: 404003c9 (nZcv DAIF +PAN -UAO)\n[1135630.269239] pc : kprobe_perf_func+0x30/0x260\n[1135630.277643] lr : kprobe_dispatcher+0x44/0x60\n[1135630.286041] sp : ffffaeff4977fa40\n[1135630.293441] x29: ffffaeff4977fa40 x28: ffffaf015340e400\n[1135630.302837] x27: 0000000000000000 x26: 0000000000000000\n[1135630.312257] x25: ffffaf029ed108a8 x24: ffffaf015340e528\n[1135630.321705] x23: ffffaeff4977fc50 x22: ffffaeff4977fc50\n[1135630.331154] x21: 0000000000000000 x20: ffffaeff4977fc50\n[1135630.340586] x19: ffffaf015340e400 x18: 0000000000000000\n[1135630.349985] x17: 0000000000000000 x16: 0000000000000000\n[1135630.359285] x15: 0000000000000000 x14: 0000000000000000\n[1135630.368445] x13: 0000000000000000 x12: 0000000000000000\n[1135630.377473] x11: 0000000000000000 x10: 0000000000000000\n[1135630.386411] x9 : 0000000000000000 x8 : 0000000000000000\n[1135630.395252] x7 : 0000000000000000 x6 : 0000000000000000\n[1135630.403963] x5 : 0000000000000000 x4 : 0000000000000000\n[1135630.412545] x3 : 0000710a04630000 x2 : 0000000000000006\n[1135630.421021] x1 : ffffaeff4977fc50 x0 : 0000710a04630000\n[1135630.429410] Call trace:\n[1135630.434828] kprobe_perf_func+0x30/0x260\n[1135630.441661] kprobe_dispatcher+0x44/0x60\n[1135630.448396] aggr_pre_handler+0x70/0xc8\n[1135630.454959] kprobe_breakpoint_handler+0x140/0x1e0\n[1135630.462435] brk_handler+0xbc/0xd8\n[1135630.468437] do_debug_exception+0x84/0x138\n[1135630.475074] el1_dbg+0x18/0x8c\n[1135630.480582] security_file_permission+0x0/0xd0\n[1135630.487426] vfs_write+0x70/0x1c0\n[1135630.493059] ksys_write+0x5c/0xc8\n[1135630.498638] __arm64_sys_write+0x24/0x30\n[1135630.504821] el0_svc_common+0x78/0x130\n[1135630.510838] el0_svc_handler+0x38/0x78\n[1135630.516834] el0_svc+0x8/0x1b0\n\nkernel/trace/trace_kprobe.c: 1308\n0xffff3df8995039ec : ldr x21, [x24,#120]\ninclude/linux/compiler.h: 294\n0xffff3df8995039f0 : ldr x1, [x21,x0]\n\nkernel/trace/trace_kprobe.c\n1308: head = this_cpu_ptr(call->perf_events);\n1309: if (hlist_empty(head))\n1310: \treturn 0;\n\ncrash> struct trace_event_call -o\nstruct trace_event_call {\n ...\n [120] struct hlist_head *perf_events; //(call->perf_event)\n ...\n}\n\ncrash> struct trace_event_call ffffaf015340e528\nstruct trace_event_call {\n ...\n perf_events = 0xffff0ad5fa89f088, //this value is correct, but x21 = 0\n ...\n}\n\nRace Condition Analysis:\n\nThe race occurs between kprobe activation and perf_events initialization:\n\n CPU0 CPU1\n ==== ====\n perf_kprobe_init\n perf_trace_event_init\n tp_event->perf_events = list;(1)\n tp_event->class->reg (2)← KPROBE ACTIVE\n Debug exception triggers\n ...\n kprobe_dispatcher\n kprobe_perf_func (tk->tp.flags & TP_FLAG_PROFILE)\n head = this_cpu_ptr(call->perf_events)(3)\n (perf_events is still NULL)\n\nProblem:\n1. CPU0 executes (1) assigning tp_event->perf_events = list\n2. CPU0 executes (2) enabling kprobe functionality via class->reg()\n3. CPU1 triggers and reaches kprobe_dispatcher\n4. CPU1 checks TP_FLAG_PROFILE - condition passes (step 2 completed)\n5. CPU1 calls kprobe_perf_func() and crashes at (3) because\n call->perf_events is still NULL\n\nCPU1 sees that kprobe functionality is enabled but does not see that\nperf_events has been assigned.\n\nAdd pairing read an\n---truncated---", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "50d780560785b068c358675c5f0bf6c83b5c373e", "status": "affected", "versionType": "git", "lessThan": "07926ce598a95de6fd874a74fb510e2ebdfd0aae" }, { "version": "50d780560785b068c358675c5f0bf6c83b5c373e", "status": "affected", "versionType": "git", "lessThan": "9c4951b691bb8d7a004acd010f45144391f85ea6" }, { "version": "50d780560785b068c358675c5f0bf6c83b5c373e", "status": "affected", "versionType": "git", "lessThan": "95dd33361061f808d1f68616d69ada639e737cfa" }, { "version": "50d780560785b068c358675c5f0bf6c83b5c373e", "status": "affected", "versionType": "git", "lessThan": "a6e89ada1ff6b70df73f579071ffa6ade8ae7f98" }, { "version": "50d780560785b068c358675c5f0bf6c83b5c373e", "status": "affected", "versionType": "git", "lessThan": "1a301228c0a8aedc3154fb1a274456f487416b96" }, { "version": "50d780560785b068c358675c5f0bf6c83b5c373e", "status": "affected", "versionType": "git", "lessThan": "0fa388ab2c290ef1115ff88ae88e881d0fb2db02" }, { "version": "50d780560785b068c358675c5f0bf6c83b5c373e", "status": "affected", "versionType": "git", "lessThan": "5ebea6561649d30ec7a18fea23d7f76738dae916" }, { "version": "50d780560785b068c358675c5f0bf6c83b5c373e", "status": "affected", "versionType": "git", "lessThan": "9cf9aa7b0acfde7545c1a1d912576e9bab28dc6f" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "2.6.33", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "2.6.33" }, { "version": "5.4.301", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.4.*" }, { "version": "5.10.246", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.10.*" }, { "version": "5.15.195", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.15.*" }, { "version": "6.1.157", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.1.*" }, { "version": "6.6.113", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.12.54", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.17.3", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.17.*" }, { "version": "6.18", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }