CVE-2025-39904
published 2025-10-01CVE-2025-39904: In the Linux kernel, the following vulnerability has been resolved: arm64: kexec: initialize kexec_buf struct in load_other_segments() Patch series "kexec: Fix…
PriorityP421medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.12%
2.3th percentile
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.
Affected
7 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | linux | < linux 6.16.8-1 (forky) | linux 6.16.8-1 (forky) |
| linux | linux | — | — |
| linux | linux | >= bf454ec31add6790f6cdc88328e38901fcbbade6 < 340cc9a3bd30b25edaf6a9708d41b5f2c10a054a | 340cc9a3bd30b25edaf6a9708d41b5f2c10a054a |
| linux | linux | >= bf454ec31add6790f6cdc88328e38901fcbbade6 < 04d3cd43700a2d0fe4bfb1012a8ec7f2e34a3507 | 04d3cd43700a2d0fe4bfb1012a8ec7f2e34a3507 |
| linux | linux_kernel | — | — |
| linux | linux_kernel | >= 0 < 6.16.8-1 | 6.16.8-1 |
| linux | linux_kernel | >= 6.16 < 6.16.8 | 6.16.8 |
CVSS provenance
nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM
vendor_debian5.5LOW
vendor_redhat5.5MEDIUM
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Red Hat
kernel: arm64: kexec: initialize kexec_buf struct in load_other_segments()
vendor_redhat·2025-10-01·CVSS 5.5
CVE-2025-39904 [MEDIUM] kernel: arm64: kexec: initialize kexec_buf struct in load_other_segments()
kernel: arm64: kexec: initialize kexec_buf struct in load_other_segments()
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 decl
Debian
CVE-2025-39904: linux - In the Linux kernel, the following vulnerability has been resolved: arm64: kexe...
vendor_debian·2025·CVSS 5.5
CVE-2025-39904 [MEDIUM] CVE-2025-39904: linux - In the Linux kernel, the following vulnerability has been resolved: arm64: kexe...
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 u
OSV
CVE-2025-39904: In the Linux kernel, the following vulnerability has been resolved: arm64: kexec: initialize kexec_buf struct in load_other_segments() Patch series "k
osv·2025-10-01·CVSS 5.5
CVE-2025-39904 [MEDIUM] CVE-2025-39904: In the Linux kernel, the following vulnerability has been resolved: arm64: kexec: initialize kexec_buf struct in load_other_segments() Patch series "k
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 u
GHSA
GHSA-9j3f-w66p-jqvg: In the Linux kernel, the following vulnerability has been resolved:
arm64: kexec: initialize kexec_buf struct in load_other_segments()
Patch series
ghsa_unreviewed·2025-10-01
CVE-2025-39904 [MEDIUM] CWE-908 GHSA-9j3f-w66p-jqvg: In the Linux kernel, the following vulnerability has been resolved:
arm64: kexec: initialize kexec_buf struct in load_other_segments()
Patch series
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 instance
No detection rules found.
No public exploits indexed.
2025-10-01
Published