CVE-2025-39992
highpriority · track · 0EPSS 0.002 · 9 %ileDEEURUEPSS · scored 2026-10-22
In the Linux kernel, the following vulnerability has been resolved: mm: swap: check for stable address space before operating on the VMA It is possible to hit a zero entry while traversing the vmas in unuse_mm() called from swapoff path and accessing it causes the OOPS: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000446--> Loading the memory from offset 0x40 on the XA_ZERO_ENTRY as address. Mem abort info: ESR = 0x0000000096000005 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x05: level 1 translation fault The issue is manifested from the below race between the fork() on a process and swapoff: fork(dup_mmap()) swapoff(unuse_mm) --------------- ----------------- 1) Identical mtree is built using __mt_dup(). 2) copy_pte_range()--> copy_nonpresent_pte(): The dst mm is added into the mmlist to be visible to the swapoff operation. 3) Fatal signal is sent to the parent process(which is the current during the fork) thus skip the duplication of the vmas and mark the vma range with XA_ZERO_ENTRY as a marker for this process that helps during exit_mmap(). 4) swapoff is tried on the 'mm' added to the 'mmlist' as part of the 2. 5) unuse_mm(), that iterates through the vma's of this 'mm' will hit the non-NULL zero entry and operating on this zero entry as a vma is resulting into the oops. The proper fix would be around not exposing this partially-valid tree to others when droping the mmap lock, which is being solved with [1]. A simpler solution would be checking for MMF_UNSTABLE, as it is set if mm_struct is not fully initialized in dup_mmap(). Thanks to Liam/Lorenzo/David for all the suggestions in fixing this issue.
remediations
Vendor fix, mitigation, or workaround guidance, as published by each source.
A vendor fix is available.
- Fixedkernel-obs-build-0:6.12.0-160000.7.1.aarch64 as component of SUSE Linux Micro Extras 6.2suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedkernel-obs-build-0:6.12.0-160000.7.1.ppc64le as component of SUSE Linux Micro Extras 6.2suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedkernel-obs-build-0:6.12.0-160000.7.1.s390x as component of SUSE Linux Micro Extras 6.2suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedkernel-obs-build-0:6.12.0-160000.7.1.x86_64 as component of SUSE Linux Micro Extras 6.2suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedkernel-syms-0:6.12.0-160000.7.1.aarch64 as component of SUSE Linux Micro Extras 6.2suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedkernel-syms-0:6.12.0-160000.7.1.ppc64le as component of SUSE Linux Micro Extras 6.2suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedkernel-syms-0:6.12.0-160000.7.1.s390x as component of SUSE Linux Micro Extras 6.2suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedkernel-syms-0:6.12.0-160000.7.1.x86_64 as component of SUSE Linux Micro Extras 6.2suse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedkernel-devel-longterm-0:6.18.16-1.1.aarch64 as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedkernel-devel-longterm-0:6.18.16-1.1.ppc64le as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedkernel-devel-longterm-0:6.18.16-1.1.s390x as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedkernel-devel-longterm-0:6.18.16-1.1.x86_64 as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedkernel-source-longterm-0:6.18.16-1.1.aarch64 as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedkernel-source-longterm-0:6.18.16-1.1.ppc64le as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedkernel-source-longterm-0:6.18.16-1.1.s390x as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedkernel-source-longterm-0:6.18.16-1.1.x86_64 as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5.5–7
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (47)
Products and version ranges known to be affected.
- IBM DataPower Gateway 10.5.0.0-10.5.0.20all versionscert_bundDEcpe:/a:ibm:datapower_gateway:10.5.0.0_-_10.5.0.20
- IBM DataPower Gateway 10.6.0.0-10.6.0.8all versionscert_bundDEcpe:/a:ibm:datapower_gateway:10.6.0.0_-_10.6.0.8
advisories (3)
Vendor and ecosystem advisories describing this.
- SUSE-SU-2026:20561-1Security update for the Linux Kernel2025-11-26csaf · suse_csafDE
Security update for the Linux Kernel
- WID-SEC-W-2025-2298Linux Kernel: Mehrere SchwachstellenDeutsch2025-10-14csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen im Linux-Kernel ausnutzen, um einen Denial of Service Angriff durchzuführen, Daten zu manipulieren und andere, nicht näher spezifizierte Angriffe durchzuführen.
- openSUSE-SU-2026:10301-1kernel-devel-longterm-6.18.16-1.1 on GA media2026-03-07csaf · suse_csafDE
kernel-devel-longterm-6.18.16-1.1 on GA media
also known as (4)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (13)
External citations — patches, advisories, analysis.
- https://git.kernel.org/stable/c/1367da7eb875d01102d2ed18654b24d261ff5393cnnvd
- https://git.kernel.org/stable/c/4e5f060d7347466f77aaff1c0d5a6c4f1fb217accnnvd
- https://git.kernel.org/stable/c/9cddad3b26dac830407d2d3c0de5205ff6d6dda0cnnvd
- https://git.kernel.org/stable/c/e4e99d69b8b8295c501b2eef89e13306b738b667cnnvd
- https://www.kernel.org/Patchcnnvd
- https://git.kernel.org/stable/c/1367da7eb875d01102d2ed18654b24d261ff5393enisa_euvd
- https://git.kernel.org/stable/c/4e5f060d7347466f77aaff1c0d5a6c4f1fb217acenisa_euvd
- https://git.kernel.org/stable/c/9cddad3b26dac830407d2d3c0de5205ff6d6dda0enisa_euvd
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