On Thu, Dec 01, 2022 at 06:18:45PM +0000, Sean Christopherson wrote: > On Thu, Dec 01, 2022, coverity-bot wrote: > > Hello! > > > > This is an experimental semi-automated report about issues detected by > > Coverity from a scan of next-20221201 as part of the linux-next scan project: > > https://scan.coverity.com/projects/linux-next-weekly-scan > > > > You're getting this email because you were associated with the identified > > lines of code (noted below) that were touched by commits: > > > > Wed Nov 9 12:31:18 2022 -0500 > > 1d0da94cdafe ("KVM: x86: do not go through ctxt->ops when emulating rsm") > > > > Coverity reported the following: > > > > *** CID 1527763: Error handling issues (CHECKED_RETURN) > > arch/x86/kvm/smm.c:631 in emulator_leave_smm() > > 625 cr4 = kvm_read_cr4(vcpu); > > 626 if (cr4 & X86_CR4_PAE) > > 627 kvm_set_cr4(vcpu, cr4 & ~X86_CR4_PAE); > > 628 > > 629 /* And finally go back to 32-bit mode. */ > > 630 efer = 0; > > vvv CID 1527763: Error handling issues (CHECKED_RETURN) > > vvv Calling "kvm_set_msr" without checking return value (as is done elsewhere 5 out of 6 times). > > 631 kvm_set_msr(vcpu, MSR_EFER, efer); > > 632 } > > 633 #endif > > 634 > > 635 /* > > 636 * Give leave_smm() a chance to make ISA-specific changes to the vCPU > > > > If this is a false positive, please let us know so we can mark it as > > It's not a false positive per se, but absent a KVM bug the call can never fail. > Ditto for the kvm_set_cr{0,4}() calls above. That said, I'm tempted to "fix" > these since we've had bugs related to this code in the past. This doesn't seem > too ugly... Yeah, that's what I've done with similar cases. "This should be impossible" get a WARN_ONCE and fail gracefully. -Kees -- Kees Cook
