From 946952f0e7c805f0779f0b854abfb98ac7075b59 Mon Sep 17 00:00:00 2001 From: Li RongQing Date: Wed, 19 Jun 2024 19:18:01 +0800 Subject: [PATCH] virt: tdx-guest: Just leak decrypted memory on unrecoverable errors BugLink: https://bugs.launchpad.net/bugs/2103869 commit 27834971f616c5e154423c578fa95e0444444ce1 upstream. 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: f4738f56d1dc ("virt: tdx-guest: Add Quote generation support using TSM_REPORTS") Signed-off-by: Li RongQing Signed-off-by: Dave Hansen Signed-off-by: Ingo Molnar Reviewed-by: Rick Edgecombe Reviewed-by: Kirill A. Shutemov Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20240619111801.25630-1-lirongqing%40baidu.com Signed-off-by: Greg Kroah-Hartman CVE-2024-57793 Signed-off-by: Manuel Diewald Signed-off-by: Mehmet Basaran --- drivers/virt/coco/tdx-guest/tdx-guest.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/virt/coco/tdx-guest/tdx-guest.c b/drivers/virt/coco/tdx-guest/tdx-guest.c index 1253bf76b570..8575d98a597a 100644 --- a/drivers/virt/coco/tdx-guest/tdx-guest.c +++ b/drivers/virt/coco/tdx-guest/tdx-guest.c @@ -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; }