Commit 6b455c10 authored by Ma Wupeng's avatar Ma Wupeng Committed by Wupeng Ma
Browse files

efi: Fix UAF for arm64 when enable efi_fake_mem 

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7F3NP


CVE: NA

--------------------------------

Efi fake mem support for arm64 is introduced for debug propose
only. However efi_memmap_init_late in arm_enable_runtime_services
will free this memory which will lead to UAF on efi.memmap.map.

In order to slove this, clear efi.memmap.flags to skip free.
Since efi map is never freed in arm64, this will not lead to
memroy leak.

Signed-off-by: default avatarMa Wupeng <mawupeng1@huawei.com>
parent f8739508

drivers/firmware/efi/fake_mem.c

+13 −0
Original line number Diff line number Diff line
@@ -61,6 +61,19 @@ static void __init efi_fake_range(struct efi_mem_range *efi_range) 
	/* swap into new EFI memmap */

	early_memunmap(new_memmap, data.size);



#ifdef CONFIG_ARM64

	/*

	 * Efi fake mem support for arm64 is introduced for debug propose

	 * only. However efi_memmap_init_late in arm_enable_runtime_services

	 * will free this memory which will lead to UAF on efi.memmap.map.

	 *

	 * In order to slove this, clear efi.memmap.flags to skip free.

	 * Since efi map is never freed in arm64, this will not lead to

	 * memroy leak.

	 */

	data.flags &= ~(EFI_MEMMAP_SLAB | EFI_MEMMAP_MEMBLOCK);

#endif



	efi_memmap_install(&data);

}