Commit 27834971 authored by Li RongQing's avatar Li RongQing Committed by Ingo Molnar
Browse files

virt: tdx-guest: Just leak decrypted memory on unrecoverable errors 



In CoCo VMs it is possible for the untrusted host to cause
set_memory_decrypted() to fail such that an error is returned
and the resulting memory is shared. Callers need to take care
to handle these errors to avoid returning decrypted (shared)
memory to the page allocator, which could lead to functional
or security issues.

Leak the decrypted memory when set_memory_decrypted() fails,
and don't need to print an error since set_memory_decrypted()
will call WARN_ONCE().

Fixes: f4738f56 ("virt: tdx-guest: Add Quote generation support using TSM_REPORTS")
Signed-off-by: default avatarLi RongQing <lirongqing@baidu.com>
Signed-off-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Reviewed-by: default avatarRick Edgecombe <rick.p.edgecombe@intel.com>
Reviewed-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20240619111801.25630-1-lirongqing%40baidu.com
parent dc81e556

drivers/virt/coco/tdx-guest/tdx-guest.c

+1 −3
Original line number Diff line number Diff line
@@ -124,10 +124,8 @@ static void *alloc_quote_buf(void) 
	if (!addr)

		return NULL;



	if (set_memory_decrypted((unsigned long)addr, count)) {

		free_pages_exact(addr, len);

	if (set_memory_decrypted((unsigned long)addr, count))

		return NULL;

	}



	return addr;

}