Bug 2426072 (CVE-2023-54278)
| Summary: | CVE-2023-54278 kernel: s390/vmem: split pages when debug pagealloc is enabled | ||
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| Product: | [Other] Security Response | Reporter: | OSIDB Bzimport <bzimport> |
| Component: | vulnerability | Assignee: | Product Security DevOps Team <prodsec-dev> |
| Status: | NEW --- | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | unspecified | Keywords: | Security |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
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| Fixed In Version: | Doc Type: | --- | |
| Doc Text: |
In the Linux kernel’s s390/vmem subsystem, a flaw exists in the handling of virtual memory area initialization when debug pagealloc is enabled. Under certain conditions, the kernel may access memory after it has been freed or mishandled during early boot or subsystem initialization, resulting in a use-after-free condition that can cause an early kernel crash or undefined behavior on affected s390 systems.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | --- | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
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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.