180 lines
11 KiB
JSON
180 lines
11 KiB
JSON
{
|
|
"dataType": "CVE_RECORD",
|
|
"dataVersion": "5.2",
|
|
"cveMetadata": {
|
|
"cveId": "CVE-2026-89747",
|
|
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
|
|
"state": "PUBLISHED",
|
|
"assignerShortName": "Linux",
|
|
"dateReserved": "2026-09-11T19:38:34.762Z",
|
|
"datePublished": "2026-09-11T19:46:52.268Z",
|
|
"dateUpdated": "2026-10-19T08:52:01.177Z"
|
|
},
|
|
"containers": {
|
|
"cna": {
|
|
"providerMetadata": {
|
|
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
|
|
"shortName": "Linux",
|
|
"dateUpdated": "2026-10-19T08:52:01.177Z"
|
|
},
|
|
"descriptions": [
|
|
{
|
|
"lang": "en",
|
|
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Fix use-after-free in trace_pipe read on sub-buffer order change\n\nWriting to buffer_subbuf_size_kb calls ring_buffer_subbuf_order_set(),\nwhich frees every sub-buffer of the ring buffer, including the reader\npage, and replaces them with newly allocated ones.\n\nReaders of trace_pipe hold pointers into those pages. ring_buffer_peek()\nlooks up an event under cpu_buffer->reader_lock but returns the event\npointer after dropping the lock, and peek_next_entry() then calls\nring_buffer_event_length() and ring_buffer_event_data() on it. If the\nsub-buffer order is changed in that window, the reader dereferences\nfreed memory:\n\n BUG: KASAN: use-after-free in ring_buffer_peek+0x3e0/0x430\n Read of size 1 at addr ffff88802a4cf010 by task syz-executor989/6002\n\n Freed by:\n free_buffer_page kernel/trace/ring_buffer.c:398 [inline]\n ring_buffer_subbuf_order_set+0x1325/0x18e0 kernel/trace/ring_buffer.c:7444\n buffer_subbuf_size_write+0x182/0x280 kernel/trace/trace.c:8221\n\nTake trace_access_lock(RING_BUFFER_ALL_CPUS) around the order change.\nThis is the lock trace_pipe readers already hold across their entire\npeek-and-print loop, so the swap can no longer race with a reader that\nis dereferencing a peeked event."
|
|
}
|
|
],
|
|
"metrics": [
|
|
{
|
|
"cvssV3_1": {
|
|
"version": "3.1",
|
|
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
|
|
"baseScore": 7.8,
|
|
"baseSeverity": "HIGH"
|
|
},
|
|
"scenarios": [
|
|
{
|
|
"lang": "en",
|
|
"value": "AV:L - The UAF is reached only via local tracefs: write() to buffer_subbuf_size_kb (buffer_subbuf_size_write -> ring_buffer_subbuf_order_set) racing with read()/splice() of trace_pipe (tracing_read_pipe -> ring_buffer_peek). No network, adjacent-radio, or physical-device path reaches this code.\nAC:L - The attacker controls both sides of the race: one thread reads trace_pipe while another writes buffer_subbuf_size_kb, which frees the reader page after dropping reader_lock. ring_buffer_peek then dereferences the stale event pointer; the attempt is retryable at will and CONFIG_TRACING is standard.\nPR:L - tracing_check_open_get_tr() checks only LOCKDOWN_TRACEFS and DAC, with no capable() gate. buffer_subbuf_size_kb (0640) and trace_pipe (0440) are delegated via uid=/gid= mounts to tracing-group accounts on Android/Perfetto, ChromeOS, and developer systems, matching CVE-2025-38101 and CVE-2026-74634.\nUI:N - The attacker opens and reads their own trace_pipe and writes buffer_subbuf_size_kb from their own threads. No victim action, mount, or file open by another user is required.\nS:U - The use-after-free corrupts kernel ring-buffer pages and metadata inside the host kernel's security authority. It can yield local privilege escalation but does not cross a VM, IOMMU, container, or hardware trust boundary.\nC:H - ring_buffer_subbuf_order_set() frees reader-page sub-buffers while ring_buffer_peek() still holds a pointer into them; peek_next_entry() and print_trace_line() then read the freed event and copy it to userspace via trace_pipe, disclosing recycled kernel heap contents.\nI:H - Freed sub-buffer pages and buffer_page objects can be reallocated while the reader still consumes attacker-controlled type_len/payload and print_trace_line() dispatches on iter->ent->type. This UAF heap corruption is exploitable for arbitrary kernel writes and control-flow hijack.\nA:H - Dereferencing the freed reader page in ring_buffer_peek()/ring_buffer_event_length() causes a kernel oops, which is the syzbot KASAN use-after-free. The attacker can retrigger that crash at will."
|
|
}
|
|
]
|
|
}
|
|
],
|
|
"affected": [
|
|
{
|
|
"product": "Linux",
|
|
"vendor": "Linux",
|
|
"defaultStatus": "unaffected",
|
|
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
|
|
"programFiles": [
|
|
"kernel/trace/trace.c"
|
|
],
|
|
"versions": [
|
|
{
|
|
"version": "f9b94daa542a8d2532f0930f01cd9aec2d19621b",
|
|
"lessThan": "05ebe1e1d7d38c2612bacfefe043a33572ae34cb",
|
|
"status": "affected",
|
|
"versionType": "git"
|
|
},
|
|
{
|
|
"version": "f9b94daa542a8d2532f0930f01cd9aec2d19621b",
|
|
"lessThan": "ddbe921ed16a0ad2d9e09574c3f3aabec7528325",
|
|
"status": "affected",
|
|
"versionType": "git"
|
|
},
|
|
{
|
|
"version": "f9b94daa542a8d2532f0930f01cd9aec2d19621b",
|
|
"lessThan": "7a49d19ff9baaf61217e5ec14199c18bc2d93ee4",
|
|
"status": "affected",
|
|
"versionType": "git"
|
|
},
|
|
{
|
|
"version": "f9b94daa542a8d2532f0930f01cd9aec2d19621b",
|
|
"lessThan": "372f8534244d632ad5118e8a87a11291b01712d3",
|
|
"status": "affected",
|
|
"versionType": "git"
|
|
}
|
|
]
|
|
},
|
|
{
|
|
"product": "Linux",
|
|
"vendor": "Linux",
|
|
"defaultStatus": "affected",
|
|
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
|
|
"programFiles": [
|
|
"kernel/trace/trace.c"
|
|
],
|
|
"versions": [
|
|
{
|
|
"version": "6.8",
|
|
"status": "affected"
|
|
},
|
|
{
|
|
"version": "0",
|
|
"lessThan": "6.8",
|
|
"status": "unaffected",
|
|
"versionType": "semver"
|
|
},
|
|
{
|
|
"version": "6.12.109",
|
|
"lessThanOrEqual": "6.12.*",
|
|
"status": "unaffected",
|
|
"versionType": "semver"
|
|
},
|
|
{
|
|
"version": "6.18.50",
|
|
"lessThanOrEqual": "6.18.*",
|
|
"status": "unaffected",
|
|
"versionType": "semver"
|
|
},
|
|
{
|
|
"version": "7.2.4",
|
|
"lessThanOrEqual": "7.2.*",
|
|
"status": "unaffected",
|
|
"versionType": "semver"
|
|
},
|
|
{
|
|
"version": "7.3",
|
|
"lessThanOrEqual": "*",
|
|
"status": "unaffected",
|
|
"versionType": "original_commit_for_fix"
|
|
}
|
|
]
|
|
}
|
|
],
|
|
"cpeApplicability": [
|
|
{
|
|
"nodes": [
|
|
{
|
|
"operator": "OR",
|
|
"negate": false,
|
|
"cpeMatch": [
|
|
{
|
|
"vulnerable": true,
|
|
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
|
|
"versionStartIncluding": "6.8",
|
|
"versionEndExcluding": "6.12.109"
|
|
},
|
|
{
|
|
"vulnerable": true,
|
|
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
|
|
"versionStartIncluding": "6.8",
|
|
"versionEndExcluding": "6.18.50"
|
|
},
|
|
{
|
|
"vulnerable": true,
|
|
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
|
|
"versionStartIncluding": "6.8",
|
|
"versionEndExcluding": "7.2.4"
|
|
},
|
|
{
|
|
"vulnerable": true,
|
|
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
|
|
"versionStartIncluding": "6.8",
|
|
"versionEndExcluding": "7.3"
|
|
}
|
|
]
|
|
}
|
|
]
|
|
}
|
|
],
|
|
"references": [
|
|
{
|
|
"url": "https://git.kernel.org/stable/c/05ebe1e1d7d38c2612bacfefe043a33572ae34cb"
|
|
},
|
|
{
|
|
"url": "https://git.kernel.org/stable/c/ddbe921ed16a0ad2d9e09574c3f3aabec7528325"
|
|
},
|
|
{
|
|
"url": "https://git.kernel.org/stable/c/7a49d19ff9baaf61217e5ec14199c18bc2d93ee4"
|
|
},
|
|
{
|
|
"url": "https://git.kernel.org/stable/c/372f8534244d632ad5118e8a87a11291b01712d3"
|
|
}
|
|
],
|
|
"title": "tracing: Fix use-after-free in trace_pipe read on sub-buffer order change",
|
|
"x_generator": {
|
|
"engine": "bippy-1.2.0"
|
|
}
|
|
}
|
|
}
|
|
} |