CVE-2023-54278
Unknown Unknown - Not Provided
Kernel Panic in Linux s390 vmem Due to Debug Pagealloc Overflow

Publication date: 2025-12-30

Last updated on: 2025-12-30

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: s390/vmem: split pages when debug pagealloc is enabled Since commit bb1520d581a3 ("s390/mm: start kernel with DAT enabled") the kernel crashes early during boot when debug pagealloc is enabled: mem auto-init: stack:off, heap alloc:off, heap free:off addressing exception: 0005 ilc:2 [#1] SMP DEBUG_PAGEALLOC Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0-rc3-09759-gc5666c912155 #630 [..] Krnl Code: 00000000001325f6: ec5600248064 cgrj %r5,%r6,8,000000000013263e 00000000001325fc: eb880002000c srlg %r8,%r8,2 #0000000000132602: b2210051 ipte %r5,%r1,%r0,0 >0000000000132606: b90400d1 lgr %r13,%r1 000000000013260a: 41605008 la %r6,8(%r5) 000000000013260e: a7db1000 aghi %r13,4096 0000000000132612: b221006d ipte %r6,%r13,%r0,0 0000000000132616: e3d0d0000171 lay %r13,4096(%r13) Call Trace: __kernel_map_pages+0x14e/0x320 __free_pages_ok+0x23a/0x5a8) free_low_memory_core_early+0x214/0x2c8 memblock_free_all+0x28/0x58 mem_init+0xb6/0x228 mm_core_init+0xb6/0x3b0 start_kernel+0x1d2/0x5a8 startup_continue+0x36/0x40 Kernel panic - not syncing: Fatal exception: panic_on_oops This is caused by using large mappings on machines with EDAT1/EDAT2. Add the code to split the mappings into 4k pages if debug pagealloc is enabled by CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT or the debug_pagealloc kernel command line option.
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Meta Information
Published
2025-12-30
Last Modified
2025-12-30
Generated
2026-05-07
AI Q&A
2025-12-30
EPSS Evaluated
2026-05-05
NVD
CVE-2023-54278
EUVD
EUVD-2023-60526
Affected Vendors & Products
Showing 2 associated CPEs
Vendor Product Version / Range
linux kernel *
linux linux_kernel *
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-UNKNOWN
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability occurs in the Linux kernel on s390 architecture when debug pagealloc is enabled. The kernel crashes early during boot due to improper handling of large memory mappings on machines with EDAT1/EDAT2. The issue is caused by not splitting large memory mappings into 4k pages, which leads to a fatal exception and kernel panic. The fix involves splitting these large mappings into 4k pages when debug pagealloc is enabled.


How can this vulnerability impact me? :

If you run the Linux kernel on s390 architecture with debug pagealloc enabled, this vulnerability can cause your system to crash early during boot, resulting in a kernel panic and preventing the system from starting properly.


What immediate steps should I take to mitigate this vulnerability?

To mitigate this vulnerability, ensure that debug pagealloc is disabled or not enabled by default. Avoid enabling debug pagealloc via the kernel command line option or the CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT setting. Additionally, update the Linux kernel to a version that includes the fix which splits large memory mappings into 4k pages when debug pagealloc is enabled.


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