Sean Christopherson 087e15206d KVM: Set file_operations.owner appropriately for all such structures ... Set .owner for all KVM-owned filed types so that the KVM module is pinned until any files with callbacks back into KVM are completely freed. Using "struct kvm" as a proxy for the module, i.e. keeping KVM-the-module alive while there are active VMs, doesn't provide full protection. Userspace can invoke delete_module() the instant the last reference to KVM is put. If KVM itself puts the last reference, e.g. via kvm_destroy_vm(), then it's possible for KVM to be preempted and deleted/unloaded before KVM fully exits, e.g. when the task running kvm_destroy_vm() is scheduled back in, it will jump to a code page that is no longer mapped. Note, file types that can call into sub-module code, e.g. kvm-intel.ko or kvm-amd.ko on x86, must use the module pointer passed to kvm_init(), not THIS_MODULE (which points at kvm.ko). KVM assumes that if /dev/kvm is reachable, e.g. VMs are active, then the vendor module is loaded. To reduce the probability of forgetting to set .owner entirely, use THIS_MODULE for stats files where KVM does not call back into vendor code. This reverts commit 70375c2d8f, and fixes several other file types that have been buggy since their introduction. Fixes: 70375c2d8f ("Revert "KVM: set owner of cpu and vm file operations"") Fixes: 3bcd0662d6 ("KVM: X86: Introduce mmu_rmaps_stat per-vm debugfs file") Reported-by: Al Viro <viro@zeniv.linux.org.uk> Link: https://lore.kernel.org/all/20231010003746.GN800259@ZenIV Link: https://lore.kernel.org/r/20231018204624.1905300-2-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>		2023-12-01 08:12:17 -08:00
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kvm	KVM: Set file_operations.owner appropriately for all such structures	2023-12-01 08:12:17 -08:00
lib	Revert "irqbypass: do not start cons/prod when failed connect"	2021-05-15 10:26:55 +01:00
Makefile	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00