CVE-2025-38733
published 2025-09-05CVE-2025-38733: In the Linux kernel, the following vulnerability has been resolved: s390/mm: Do not map lowcore with identity mapping Since the identity mapping is pinned to…
PriorityP419medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.14%
4.1th percentile
In the Linux kernel, the following vulnerability has been resolved:
s390/mm: Do not map lowcore with identity mapping
Since the identity mapping is pinned to address zero the lowcore is always
also mapped to address zero, this happens regardless of the relocate_lowcore
command line option. If the option is specified the lowcore is mapped
twice, instead of only once.
This means that NULL pointer accesses will succeed instead of causing an
exception (low address protection still applies, but covers only parts).
To fix this never map the first two pages of physical memory with the
identity mapping.
Affected
14 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | linux | < linux 6.16.5-1 (forky) | linux 6.16.5-1 (forky) |
| linux | linux | — | — |
| linux | linux | — | — |
| linux | linux | >= 32db401965f165f7c44447d0508097f070c8f576 < 30bf5728bb217a6d1ba73f44094c9b9c6bc9a567 | 30bf5728bb217a6d1ba73f44094c9b9c6bc9a567 |
| linux | linux | >= 32db401965f165f7c44447d0508097f070c8f576 < 1d7864acd497cb468a998d44631f84896f885e85 | 1d7864acd497cb468a998d44631f84896f885e85 |
| linux | linux | >= 32db401965f165f7c44447d0508097f070c8f576 < 93f616ff870a1fb7e84d472cad0af651b18f9f87 | 93f616ff870a1fb7e84d472cad0af651b18f9f87 |
| linux | linux | >= 6.10.11 < 6.11 | 6.11 |
| linux | linux_kernel | — | — |
| linux | linux_kernel | — | — |
| linux | linux_kernel | >= 0 < 6.12.48-1 | 6.12.48-1 |
| linux | linux_kernel | >= 0 < 6.16.5-1 | 6.16.5-1 |
| linux | linux_kernel | >= 6.10.11 < 6.11 | 6.11 |
| linux | linux_kernel | >= 6.11.1 < 6.12.44 | 6.12.44 |
| linux | linux_kernel | >= 6.13 < 6.16.4 | 6.16.4 |
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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OSV
CVE-2025-38733: In the Linux kernel, the following vulnerability has been resolved: s390/mm: Do not map lowcore with identity mapping Since the identity mapping is pi
osv·2025-09-05·CVSS 5.5
CVE-2025-38733 [MEDIUM] CVE-2025-38733: In the Linux kernel, the following vulnerability has been resolved: s390/mm: Do not map lowcore with identity mapping Since the identity mapping is pi
In the Linux kernel, the following vulnerability has been resolved: s390/mm: Do not map lowcore with identity mapping Since the identity mapping is pinned to address zero the lowcore is always also mapped to address zero, this happens regardless of the relocate_lowcore command line option. If the option is specified the lowcore is mapped twice, instead of only once. This means that NULL pointer accesses will succeed instead of causing an exception (low address protection still applies, but covers only parts). To fix this never map the first two pages of physical memory with the identity mapping.
GHSA
GHSA-9w66-p46h-j52f: In the Linux kernel, the following vulnerability has been resolved:
s390/mm: Do not map lowcore with identity mapping
Since the identity mapping is
ghsa_unreviewed·2025-09-05
CVE-2025-38733 [MEDIUM] CWE-476 GHSA-9w66-p46h-j52f: In the Linux kernel, the following vulnerability has been resolved:
s390/mm: Do not map lowcore with identity mapping
Since the identity mapping is
In the Linux kernel, the following vulnerability has been resolved:
s390/mm: Do not map lowcore with identity mapping
Since the identity mapping is pinned to address zero the lowcore is always
also mapped to address zero, this happens regardless of the relocate_lowcore
command line option. If the option is specified the lowcore is mapped
twice, instead of only once.
This means that NULL pointer accesses will succeed instead of causing an
exception (low address protection still applies, but covers only parts).
To fix this never map the first two pages of physical memory with the
identity mapping.
Red Hat
kernel: Linux kernel: Denial of Service due to incorrect lowcore memory mapping
vendor_redhat·2025-09-05·CVSS 5.5
CVE-2025-38733 [MEDIUM] CWE-476 kernel: Linux kernel: Denial of Service due to incorrect lowcore memory mapping
kernel: Linux kernel: Denial of Service due to incorrect lowcore memory mapping
In the Linux kernel, the following vulnerability has been resolved:
s390/mm: Do not map lowcore with identity mapping
Since the identity mapping is pinned to address zero the lowcore is always
also mapped to address zero, this happens regardless of the relocate_lowcore
command line option. If the option is specified the lowcore is mapped
twice, instead of only once.
This means that NULL pointer accesses will succeed instead of causing an
exception (low address protection still applies, but covers only parts).
To fix this never map the first two pages of physical memory with the
identity mapping.
A flaw was found in the Linux kernel. Due to an incorrect identity mapping of the lowcore, a critical memory region
Debian
CVE-2025-38733: linux - In the Linux kernel, the following vulnerability has been resolved: s390/mm: Do...
vendor_debian·2025·CVSS 5.5
CVE-2025-38733 [MEDIUM] CVE-2025-38733: linux - In the Linux kernel, the following vulnerability has been resolved: s390/mm: Do...
In the Linux kernel, the following vulnerability has been resolved: s390/mm: Do not map lowcore with identity mapping Since the identity mapping is pinned to address zero the lowcore is always also mapped to address zero, this happens regardless of the relocate_lowcore command line option. If the option is specified the lowcore is mapped twice, instead of only once. This means that NULL pointer accesses will succeed instead of causing an exception (low address protection still applies, but covers only parts). To fix this never map the first two pages of physical memory with the identity mapping.
Scope: local
bookworm: resolved
bullseye: resolved
forky: resolved (fixed in 6.16.5-1)
sid: resolved (fixed in 6.16.5-1)
trixie: resolved (fixed in 6.12.48-1)
No detection rules found.
No public exploits indexed.
2025-09-05
Published