From 1a726cb47fd204109c767409fa9ca15a96328f14 Mon Sep 17 00:00:00 2001 From: George Kennedy Date: Mon, 28 Nov 2022 15:18:25 -0500 Subject: [PATCH] VMCI: check context->notify_page after call to get_user_pages_fast() to avoid GPF The call to get_user_pages_fast() in vmci_host_setup_notify() can return NULL context->notify_page causing a GPF. To avoid GPF check if context->notify_page == NULL and return error if so. general protection fault, probably for non-canonical address 0xe0009d1000000060: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: maybe wild-memory-access in range [0x0005088000000300- 0x0005088000000307] CPU: 2 PID: 26180 Comm: repro_34802241 Not tainted 6.1.0-rc4 #1 Hardware name: Red Hat KVM, BIOS 1.15.0-2.module+el8.6.0 04/01/2014 RIP: 0010:vmci_ctx_check_signal_notify+0x91/0xe0 Call Trace: vmci_host_unlocked_ioctl+0x362/0x1f40 __x64_sys_ioctl+0x1a1/0x230 do_syscall_64+0x3a/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: a1d88436d53a ("VMCI: Fix two UVA mapping bugs") Reported-by: syzkaller Signed-off-by: George Kennedy Reviewed-by: Vishnu Dasa Link: https://lore.kernel.org/r/1669666705-24012-1-git-send-email-george.kennedy@oracle.com Signed-off-by: Greg Kroah-Hartman --- drivers/misc/vmw_vmci/vmci_host.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/misc/vmw_vmci/vmci_host.c b/drivers/misc/vmw_vmci/vmci_host.c index da1e2a773823e0..857b9851402a62 100644 --- a/drivers/misc/vmw_vmci/vmci_host.c +++ b/drivers/misc/vmw_vmci/vmci_host.c @@ -242,6 +242,8 @@ static int vmci_host_setup_notify(struct vmci_ctx *context, context->notify_page = NULL; return VMCI_ERROR_GENERIC; } + if (context->notify_page == NULL) + return VMCI_ERROR_UNAVAILABLE; /* * Map the locked page and set up notify pointer.