CVE-2025-39904 (GCVE-0-2025-39904)
Vulnerability from cvelistv5
Published
2025-10-01 07:44
Modified
2025-10-01 07:44
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
arm64: kexec: initialize kexec_buf struct in load_other_segments()
Patch series "kexec: Fix invalid field access".
The kexec_buf structure was previously declared without initialization.
commit bf454ec31add ("kexec_file: allow to place kexec_buf randomly")
added a field that is always read but not consistently populated by all
architectures. This un-initialized field will contain garbage.
This is also triggering a UBSAN warning when the uninitialized data was
accessed:
------------[ cut here ]------------
UBSAN: invalid-load in ./include/linux/kexec.h:210:10
load of value 252 is not a valid value for type '_Bool'
Zero-initializing kexec_buf at declaration ensures all fields are cleanly
set, preventing future instances of uninitialized memory being used.
An initial fix was already landed for arm64[0], and this patchset fixes
the problem on the remaining arm64 code and on riscv, as raised by Mark.
Discussions about this problem could be found at[1][2].
This patch (of 3):
The kexec_buf structure was previously declared without initialization.
commit bf454ec31add ("kexec_file: allow to place kexec_buf randomly")
added a field that is always read but not consistently populated by all
architectures. This un-initialized field will contain garbage.
This is also triggering a UBSAN warning when the uninitialized data was
accessed:
------------[ cut here ]------------
UBSAN: invalid-load in ./include/linux/kexec.h:210:10
load of value 252 is not a valid value for type '_Bool'
Zero-initializing kexec_buf at declaration ensures all fields are
cleanly set, preventing future instances of uninitialized memory being
used.
References
Impacted products
{
"containers": {
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"programFiles": [
"arch/arm64/kernel/machine_kexec_file.c"
],
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"versions": [
{
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"version": "6.16"
},
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"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.16.*",
"status": "unaffected",
"version": "6.16.8",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "6.17",
"versionType": "original_commit_for_fix"
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{
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"descriptions": [
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"value": "In the Linux kernel, the following vulnerability has been resolved:\n\narm64: kexec: initialize kexec_buf struct in load_other_segments()\n\nPatch series \"kexec: Fix invalid field access\".\n\nThe kexec_buf structure was previously declared without initialization. \ncommit bf454ec31add (\"kexec_file: allow to place kexec_buf randomly\")\nadded a field that is always read but not consistently populated by all\narchitectures. This un-initialized field will contain garbage.\n\nThis is also triggering a UBSAN warning when the uninitialized data was\naccessed:\n\n\t------------[ cut here ]------------\n\tUBSAN: invalid-load in ./include/linux/kexec.h:210:10\n\tload of value 252 is not a valid value for type \u0027_Bool\u0027\n\nZero-initializing kexec_buf at declaration ensures all fields are cleanly\nset, preventing future instances of uninitialized memory being used.\n\nAn initial fix was already landed for arm64[0], and this patchset fixes\nthe problem on the remaining arm64 code and on riscv, as raised by Mark.\n\nDiscussions about this problem could be found at[1][2].\n\n\nThis patch (of 3):\n\nThe kexec_buf structure was previously declared without initialization.\ncommit bf454ec31add (\"kexec_file: allow to place kexec_buf randomly\")\nadded a field that is always read but not consistently populated by all\narchitectures. This un-initialized field will contain garbage.\n\nThis is also triggering a UBSAN warning when the uninitialized data was\naccessed:\n\n\t------------[ cut here ]------------\n\tUBSAN: invalid-load in ./include/linux/kexec.h:210:10\n\tload of value 252 is not a valid value for type \u0027_Bool\u0027\n\nZero-initializing kexec_buf at declaration ensures all fields are\ncleanly set, preventing future instances of uninitialized memory being\nused."
}
],
"providerMetadata": {
"dateUpdated": "2025-10-01T07:44:27.739Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/340cc9a3bd30b25edaf6a9708d41b5f2c10a054a"
},
{
"url": "https://git.kernel.org/stable/c/04d3cd43700a2d0fe4bfb1012a8ec7f2e34a3507"
}
],
"title": "arm64: kexec: initialize kexec_buf struct in load_other_segments()",
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"cveMetadata": {
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"assignerShortName": "Linux",
"cveId": "CVE-2025-39904",
"datePublished": "2025-10-01T07:44:27.739Z",
"dateReserved": "2025-04-16T07:20:57.146Z",
"dateUpdated": "2025-10-01T07:44:27.739Z",
"state": "PUBLISHED"
},
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"nvd": "{\"cve\":{\"id\":\"CVE-2025-39904\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2025-10-01T08:15:33.250\",\"lastModified\":\"2025-10-02T19:12:17.160\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\narm64: kexec: initialize kexec_buf struct in load_other_segments()\\n\\nPatch series \\\"kexec: Fix invalid field access\\\".\\n\\nThe kexec_buf structure was previously declared without initialization. \\ncommit bf454ec31add (\\\"kexec_file: allow to place kexec_buf randomly\\\")\\nadded a field that is always read but not consistently populated by all\\narchitectures. This un-initialized field will contain garbage.\\n\\nThis is also triggering a UBSAN warning when the uninitialized data was\\naccessed:\\n\\n\\t------------[ cut here ]------------\\n\\tUBSAN: invalid-load in ./include/linux/kexec.h:210:10\\n\\tload of value 252 is not a valid value for type \u0027_Bool\u0027\\n\\nZero-initializing kexec_buf at declaration ensures all fields are cleanly\\nset, preventing future instances of uninitialized memory being used.\\n\\nAn initial fix was already landed for arm64[0], and this patchset fixes\\nthe problem on the remaining arm64 code and on riscv, as raised by Mark.\\n\\nDiscussions about this problem could be found at[1][2].\\n\\n\\nThis patch (of 3):\\n\\nThe kexec_buf structure was previously declared without initialization.\\ncommit bf454ec31add (\\\"kexec_file: allow to place kexec_buf randomly\\\")\\nadded a field that is always read but not consistently populated by all\\narchitectures. This un-initialized field will contain garbage.\\n\\nThis is also triggering a UBSAN warning when the uninitialized data was\\naccessed:\\n\\n\\t------------[ cut here ]------------\\n\\tUBSAN: invalid-load in ./include/linux/kexec.h:210:10\\n\\tload of value 252 is not a valid value for type \u0027_Bool\u0027\\n\\nZero-initializing kexec_buf at declaration ensures all fields are\\ncleanly set, preventing future instances of uninitialized memory being\\nused.\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/04d3cd43700a2d0fe4bfb1012a8ec7f2e34a3507\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/340cc9a3bd30b25edaf6a9708d41b5f2c10a054a\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
}
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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