VMCI: check context->notify_page after call to get_user_pages_fast() to avoid GPF

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: 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: <TASK> vmci_host_unlocked_ioctl+0x362/0x1f40 __x64_sys_ioctl+0x1a1/0x230 do_syscall_64+0x3a/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd

References

• https://git.kernel.org/stable/c/b4239bfb260d1e6837766c41a0b241d7670f1402
• https://git.kernel.org/stable/c/d4198f67e7556b1507f14f60d81a72660e5560e4
• https://git.kernel.org/stable/c/a3c89e8c69a58f62451c0a75b77fcab25979b897
• https://git.kernel.org/stable/c/055891397f530f9b1b22be38d7eca8b08382941f
• https://git.kernel.org/stable/c/91b8e4f61f8f4594ee65368c8d89e6fdc29d3fb1
• https://git.kernel.org/stable/c/1a726cb47fd204109c767409fa9ca15a96328f14