mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-03 22:57:21 -04:00
64c947a1cf
Extend KVM's restrictions on userspace forcing "emulation required" at odd times to cover stuffing invalid guest state while a nested run is pending. Clobbering guest state while KVM is in the middle of emulating VM-Enter is nonsensical, as it puts the vCPU into an architecturally impossible state, and will trip KVM's sanity check that guards against KVM bugs, e.g. helps detect missed VMX consistency checks. WARNING: CPU: 3 PID: 6336 at arch/x86/kvm/vmx/vmx.c:6480 __vmx_handle_exit arch/x86/kvm/vmx/vmx.c:6480 [inline] WARNING: CPU: 3 PID: 6336 at arch/x86/kvm/vmx/vmx.c:6480 vmx_handle_exit+0x40f/0x1f70 arch/x86/kvm/vmx/vmx.c:6637 Modules linked in: CPU: 3 UID: 0 PID: 6336 Comm: syz.0.73 Not tainted 6.13.0-rc1-syzkaller-00316-gb5f217084ab3 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:__vmx_handle_exit arch/x86/kvm/vmx/vmx.c:6480 [inline] RIP: 0010:vmx_handle_exit+0x40f/0x1f70 arch/x86/kvm/vmx/vmx.c:6637 <TASK> vcpu_enter_guest arch/x86/kvm/x86.c:11081 [inline] vcpu_run+0x3047/0x4f50 arch/x86/kvm/x86.c:11242 kvm_arch_vcpu_ioctl_run+0x44a/0x1740 arch/x86/kvm/x86.c:11560 kvm_vcpu_ioctl+0x6ce/0x1520 virt/kvm/kvm_main.c:4340 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f </TASK> Reported-by: syzbot+ac0bc3a70282b4d586cc@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/67598fb9.050a0220.17f54a.003b.GAE@google.com Debugged-by: James Houghton <jthoughton@google.com> Tested-by: James Houghton <jthoughton@google.com> Link: https://lore.kernel.org/r/20250224171409.2348647-1-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.