RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-05-31 04:38:11 +00:00
Code Issues Activity Actions

Kernel: Handle mmap requests on zero-length data file inodes safely

Browse source
This commit is contained in:
Liav A 2022-08-06 21:05:48 +03:00 • committed by Idan Horowitz
parent c88cc8557f
commit 3ad0e1a1d5
5 changed files with 28 additions and 5 deletions
Download patch file Download diff file Expand all files Collapse all files

13
Kernel/Memory/PrivateInodeVMObject.cpp
View file

@ -11,7 +11,18 @@ namespace Kernel::Memory {
ErrorOr<NonnullLockRefPtr<PrivateInodeVMObject>> PrivateInodeVMObject::try_create_with_inode(Inode& inode)
{
auto new_physical_pages = TRY(VMObject::try_create_physical_pages(inode.size()));
if (inode.size() == 0)
return EINVAL;
return try_create_with_inode_and_range(inode, 0, inode.size());
}
ErrorOr<NonnullLockRefPtr<PrivateInodeVMObject>> PrivateInodeVMObject::try_create_with_inode_and_range(Inode& inode, u64 offset, size_t range_size)
{
// Note: To ensure further allocation of a Region with this VMObject will not complain
// on "smaller" VMObject than the requested Region, we simply take the max size between both values.
auto size = max(inode.size(), (offset + range_size));
VERIFY(size > 0);
auto new_physical_pages = TRY(VMObject::try_create_physical_pages(size));
auto dirty_pages = TRY(Bitmap::try_create(new_physical_pages.size(), false));
return adopt_nonnull_lock_ref_or_enomem(new (nothrow) PrivateInodeVMObject(inode, move(new_physical_pages), move(dirty_pages)));
}