From 1a726cb47fd204109c767409fa9ca15a96328f14 Mon Sep 17 00:00:00 2001
From: George Kennedy <george.kennedy@oracle.com>
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
Git-commit: 1a726cb47fd204109c767409fa9ca15a96328f14
Patch-mainline: v6.3-rc1
References: git-fixes
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:
<TASK>
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 <syzkaller@googlegroups.com>
Signed-off-by: George Kennedy <george.kennedy@oracle.com>
Reviewed-by: Vishnu Dasa <vdasa@vmware.com>
Link: https://lore.kernel.org/r/1669666705-24012-1-git-send-email-george.kennedy@oracle.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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 da1e2a773823..857b9851402a 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.
--
2.35.3