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authorJakub Kicinski <kuba@kernel.org>2021-07-31 19:14:46 +0300
committerJakub Kicinski <kuba@kernel.org>2021-07-31 19:14:46 +0300
commitd2e11fd2b7fcd10b7bcef418c55490c934aa94e8 (patch)
treebdce7769cd4d69b375aad004e844d1a413863485 /arch/powerpc/kvm/book3s_rtas.c
parentaae950b189413ed3201354600d44223da0bcf63c (diff)
parentc7d102232649226a69dddd58a4942cf13cff4f7c (diff)
downloadlinux-d2e11fd2b7fcd10b7bcef418c55490c934aa94e8.tar.xz
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Conflicting commits, all resolutions pretty trivial: drivers/bus/mhi/pci_generic.c 5c2c85315948 ("bus: mhi: pci-generic: configurable network interface MRU") 56f6f4c4eb2a ("bus: mhi: pci_generic: Apply no-op for wake using sideband wake boolean") drivers/nfc/s3fwrn5/firmware.c a0302ff5906a ("nfc: s3fwrn5: remove unnecessary label") 46573e3ab08f ("nfc: s3fwrn5: fix undefined parameter values in dev_err()") 801e541c79bb ("nfc: s3fwrn5: fix undefined parameter values in dev_err()") MAINTAINERS 7d901a1e878a ("net: phy: add Maxlinear GPY115/21x/24x driver") 8a7b46fa7902 ("MAINTAINERS: add Yasushi SHOJI as reviewer for the Microchip CAN BUS Analyzer Tool driver") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'arch/powerpc/kvm/book3s_rtas.c')
-rw-r--r--arch/powerpc/kvm/book3s_rtas.c25
1 files changed, 22 insertions, 3 deletions
diff --git a/arch/powerpc/kvm/book3s_rtas.c b/arch/powerpc/kvm/book3s_rtas.c
index c5e677508d3b..0f847f1e5ddd 100644
--- a/arch/powerpc/kvm/book3s_rtas.c
+++ b/arch/powerpc/kvm/book3s_rtas.c
@@ -242,6 +242,17 @@ int kvmppc_rtas_hcall(struct kvm_vcpu *vcpu)
* value so we can restore it on the way out.
*/
orig_rets = args.rets;
+ if (be32_to_cpu(args.nargs) >= ARRAY_SIZE(args.args)) {
+ /*
+ * Don't overflow our args array: ensure there is room for
+ * at least rets[0] (even if the call specifies 0 nret).
+ *
+ * Each handler must then check for the correct nargs and nret
+ * values, but they may always return failure in rets[0].
+ */
+ rc = -EINVAL;
+ goto fail;
+ }
args.rets = &args.args[be32_to_cpu(args.nargs)];
mutex_lock(&vcpu->kvm->arch.rtas_token_lock);
@@ -269,9 +280,17 @@ int kvmppc_rtas_hcall(struct kvm_vcpu *vcpu)
fail:
/*
* We only get here if the guest has called RTAS with a bogus
- * args pointer. That means we can't get to the args, and so we
- * can't fail the RTAS call. So fail right out to userspace,
- * which should kill the guest.
+ * args pointer or nargs/nret values that would overflow the
+ * array. That means we can't get to the args, and so we can't
+ * fail the RTAS call. So fail right out to userspace, which
+ * should kill the guest.
+ *
+ * SLOF should actually pass the hcall return value from the
+ * rtas handler call in r3, so enter_rtas could be modified to
+ * return a failure indication in r3 and we could return such
+ * errors to the guest rather than failing to host userspace.
+ * However old guests that don't test for failure could then
+ * continue silently after errors, so for now we won't do this.
*/
return rc;
}