diff options
| author | Mark Rowe <mark@vector35.com> | 2025-10-22 19:52:19 -0700 |
|---|---|---|
| committer | Mark Rowe <mark@vector35.com> | 2025-10-23 13:33:08 -0700 |
| commit | 9a8faad50f56d748fcd1498c170797c67bb53217 (patch) | |
| tree | 2b39b444d1c51c680a89d86de40af85b5f913592 /view/kernelcache/core/MachOProcessor.cpp | |
| parent | b57e208e1aa7f261cb1d0980cada3af1c05fe6d1 (diff) | |
[KernelCache] Set segment permissions based on how XNU initially maps them
XNU maps kernel cache segments in with different permissions than the
load commands indicate. For instance, `__DATA_CONST` is initially mapped
as read-write before later being re-mapped as read-only. Treating it as
read-only results in analysis falsely assuming that global variables
cannot change.
To work around this we maintain a mapping from segment name to initial
permissions (i.e., most lax permissions) and favor them over permissions
derived from the segment load command. Section semantics are also
derived from the segment's permissions when the segment is present in
the mapping.
The mapping is based on the initial permissions established by
`arm_vm_prot_init` within the XNU source.
Diffstat (limited to 'view/kernelcache/core/MachOProcessor.cpp')
| -rw-r--r-- | view/kernelcache/core/MachOProcessor.cpp | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/view/kernelcache/core/MachOProcessor.cpp b/view/kernelcache/core/MachOProcessor.cpp index 42faba24..fb3d2b27 100644 --- a/view/kernelcache/core/MachOProcessor.cpp +++ b/view/kernelcache/core/MachOProcessor.cpp @@ -193,8 +193,9 @@ uint64_t KernelCacheMachOProcessor::ApplyHeaderSections(KernelCacheMachOHeader& semantics = ReadWriteDataSectionSemantics; if (strncmp(section.sectname, "__auth_got", sizeof(section.sectname)) == 0) semantics = ReadOnlyDataSectionSemantics; - if (strncmp(section.segname, "__DATA_CONST", sizeof(section.segname)) == 0) - semantics = ReadOnlyDataSectionSemantics; + + if (auto overriddenSemantics = SectionSemanticsForSection(section)) + semantics = static_cast<BNSectionSemantics>(overriddenSemantics); // Typically a view would add auto sections but those won't persist when loading the BNDB. // if we want to use an auto section here we would need to allow the core to apply auto sections from the database. |