CVE-2026-98655
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: perf: Require kernel access for text poke events Perf events with exclude_kernel=1 can be opened without kernel perf access. However, exclude_kernel does not suppress text-poke sideband records. Every PERF_RECORD_TEXT_POKE is marked PERF_RECORD_MISC_KERNEL and contains a raw kernel instruction address. An unprivileged task can therefore open and mmap a task-local software event with text_poke=1. Both opening a count-only tracepoint event and configuring UDP GRO for ESP-in-UDP cause updates to inline static calls; the observer receives the relocated addresses of the modified instructions. For a known kernel image, any such address reveals the runtime kernel text base despite KASLR. Call perf_allow_kernel() whenever attr.text_poke is set, regardless of exclude_kernel. Events that neither monitor kernel execution nor request text-poke records retain their existing permissions.
Severity
Not scored
CVSS score
Not available
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-10-18 16:17:18.797000
Last modified
2026-10-30 13:21:16.220000
View original CVE JSON
{
"id": "CVE-2026-98655",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-10-18T16:17:18.797",
"lastModified": "2026-10-30T13:21:16.220",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nperf: Require kernel access for text poke events\n\nPerf events with exclude_kernel=1 can be opened without kernel perf\naccess. However, exclude_kernel does not suppress text-poke sideband\nrecords. Every PERF_RECORD_TEXT_POKE is marked PERF_RECORD_MISC_KERNEL\nand contains a raw kernel instruction address.\n\nAn unprivileged task can therefore open and mmap a task-local software\nevent with text_poke=1. Both opening a count-only tracepoint event and\nconfiguring UDP GRO for ESP-in-UDP cause updates to inline static calls;\nthe observer receives the relocated addresses of the modified instructions.\nFor a known kernel image, any such address reveals the runtime kernel\ntext base despite KASLR.\n\nCall perf_allow_kernel() whenever attr.text_poke is set, regardless of\nexclude_kernel. Events that neither monitor kernel execution nor request\ntext-poke records retain their existing permissions."
}
],
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{
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"affectedData": [
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"defaultStatus": "unaffected",
"programFiles": [
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],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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"metrics": {},
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