From a2ac07fe292ea41296049dfdbfeed203e2467ee7 Mon Sep 17 00:00:00 2001 From: Gleb Natapov Date: Tue, 1 Oct 2013 19:58:36 +0300 Subject: Fix NULL dereference in gfn_to_hva_prot() gfn_to_memslot() can return NULL or invalid slot. We need to check slot validity before accessing it. Reviewed-by: Paolo Bonzini Signed-off-by: Gleb Natapov --- virt/kvm/kvm_main.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'virt/kvm/kvm_main.c') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 979bff485fb..a9dd682cf5e 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1064,10 +1064,12 @@ EXPORT_SYMBOL_GPL(gfn_to_hva); unsigned long gfn_to_hva_prot(struct kvm *kvm, gfn_t gfn, bool *writable) { struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn); - if (writable) + unsigned long hva = __gfn_to_hva_many(slot, gfn, NULL, false); + + if (!kvm_is_error_hva(hva) && writable) *writable = !memslot_is_readonly(slot); - return __gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, NULL, false); + return hva; } static int kvm_read_hva(void *data, void __user *hva, int len) -- cgit v1.2.3-70-g09d2 From 0c8eb04a6241da28deb108181213b791c378123b Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 30 Oct 2013 12:12:13 +0100 Subject: KVM: use a more sensible error number when debugfs directory creation fails I don't know if this was due to cut and paste, or somebody was really using a D20 to pick the error code for kvm_init_debugfs as suggested by Linus (EFAULT is 14, so the possibility cannot be entirely ruled out). In any case, this patch fixes it. Reported-by: Tim Gardner Signed-off-by: Paolo Bonzini --- virt/kvm/kvm_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'virt/kvm/kvm_main.c') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index a9dd682cf5e..1cf9ccb0101 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -3091,7 +3091,7 @@ static const struct file_operations *stat_fops[] = { static int kvm_init_debug(void) { - int r = -EFAULT; + int r = -EEXIST; struct kvm_stats_debugfs_item *p; kvm_debugfs_dir = debugfs_create_dir("kvm", NULL); -- cgit v1.2.3-70-g09d2