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.
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.
Metrics
Affected Vendors & Products
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Thu, 02 Oct 2025 12:15:00 +0000
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References |
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Metrics |
threat_severity
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cvssV3_1
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Thu, 02 Oct 2025 09:00:00 +0000
Type | Values Removed | Values Added |
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First Time appeared |
Linux
Linux linux Kernel |
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Vendors & Products |
Linux
Linux linux Kernel |
Wed, 01 Oct 2025 08:00:00 +0000
Type | Values Removed | Values Added |
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Description | 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. | |
Title | arm64: kexec: initialize kexec_buf struct in load_other_segments() | |
References |
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-10-01T07:44:27.739Z
Reserved: 2025-04-16T07:20:57.146Z
Link: CVE-2025-39904

No data.

Status : Received
Published: 2025-10-01T08:15:33.250
Modified: 2025-10-01T08:15:33.250
Link: CVE-2025-39904


Updated: 2025-10-02T08:40:06Z