RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-10-31 14:02:46 +00:00
Code Issues Activity Actions

Kernel: Don't consider kernel memory regions for syscall origin check

Browse source 
We should never enter the syscall handler from a kernel address.
This commit is contained in:
Andreas Kling 2021-04-20 21:01:13 +02:00
parent d71f64b97f
commit c6b7b98b64
3 changed files with 6 additions and 6 deletions
Download patch file Download diff file Expand all files Collapse all files

2
Kernel/Syscall.cpp
View file

@ -190,7 +190,7 @@ void syscall_handler(TrapFrame* trap)
handle_crash(regs, "Bad stack on syscall entry", SIGSTKFLT); handle_crash(regs, "Bad stack on syscall entry", SIGSTKFLT);
} }
auto* calling_region = MM.find_region_from_vaddr(process.space(), VirtualAddress(regs.eip)); auto* calling_region = MM.find_user_region_from_vaddr(process.space(), VirtualAddress(regs.eip));
if (!calling_region) { if (!calling_region) {
dbgln("Syscall from {:p} which has no associated region", regs.eip); dbgln("Syscall from {:p} which has no associated region", regs.eip);
handle_crash(regs, "Syscall from unknown region", SIGSEGV); handle_crash(regs, "Syscall from unknown region", SIGSEGV);

8
Kernel/VM/MemoryManager.cpp
View file

@ -431,7 +431,7 @@ Region* MemoryManager::kernel_region_from_vaddr(VirtualAddress vaddr)
return nullptr; return nullptr;
} }
Region* MemoryManager::user_region_from_vaddr(Space& space, VirtualAddress vaddr) Region* MemoryManager::find_user_region_from_vaddr(Space& space, VirtualAddress vaddr)
{ {
ScopedSpinLock lock(space.get_lock()); ScopedSpinLock lock(space.get_lock());
return space.find_region_containing({ vaddr, 1 }); return space.find_region_containing({ vaddr, 1 });
@ -440,7 +440,7 @@ Region* MemoryManager::user_region_from_vaddr(Space& space, VirtualAddress vaddr
Region* MemoryManager::find_region_from_vaddr(Space& space, VirtualAddress vaddr) Region* MemoryManager::find_region_from_vaddr(Space& space, VirtualAddress vaddr)
{ {
ScopedSpinLock lock(s_mm_lock); ScopedSpinLock lock(s_mm_lock);
if (auto* region = user_region_from_vaddr(space, vaddr)) if (auto* region = find_user_region_from_vaddr(space, vaddr))
return region; return region;
return kernel_region_from_vaddr(vaddr); return kernel_region_from_vaddr(vaddr);
} }
@ -454,7 +454,7 @@ Region* MemoryManager::find_region_from_vaddr(VirtualAddress vaddr)
if (!page_directory) if (!page_directory)
return nullptr; return nullptr;
VERIFY(page_directory->space()); VERIFY(page_directory->space());
return user_region_from_vaddr(*page_directory->space(), vaddr); return find_user_region_from_vaddr(*page_directory->space(), vaddr);
} }
PageFaultResponse MemoryManager::handle_page_fault(const PageFault& fault) PageFaultResponse MemoryManager::handle_page_fault(const PageFault& fault)
@ -855,7 +855,7 @@ bool MemoryManager::validate_user_stack(const Process& process, VirtualAddress v
if (!is_user_address(vaddr)) if (!is_user_address(vaddr))
return false; return false;
ScopedSpinLock lock(s_mm_lock); ScopedSpinLock lock(s_mm_lock);
auto* region = user_region_from_vaddr(const_cast<Process&>(process).space(), vaddr); auto* region = find_user_region_from_vaddr(const_cast<Process&>(process).space(), vaddr);
return region && region->is_user() && region->is_stack(); return region && region->is_user() && region->is_stack();
} }

2
Kernel/VM/MemoryManager.h
View file

@ -188,6 +188,7 @@ public:
} }
static Region* find_region_from_vaddr(Space&, VirtualAddress); static Region* find_region_from_vaddr(Space&, VirtualAddress);
static Region* find_user_region_from_vaddr(Space&, VirtualAddress);
void dump_kernel_regions(); void dump_kernel_regions();
@ -215,7 +216,6 @@ private:
static void flush_tlb_local(VirtualAddress, size_t page_count = 1); static void flush_tlb_local(VirtualAddress, size_t page_count = 1);
static void flush_tlb(const PageDirectory*, VirtualAddress, size_t page_count = 1); static void flush_tlb(const PageDirectory*, VirtualAddress, size_t page_count = 1);
static Region* user_region_from_vaddr(Space&, VirtualAddress);
static Region* kernel_region_from_vaddr(VirtualAddress); static Region* kernel_region_from_vaddr(VirtualAddress);
static Region* find_region_from_vaddr(VirtualAddress); static Region* find_region_from_vaddr(VirtualAddress);