linux-kernel - [PATCH 1/8] KVM: selftests: Fix mostly theoretical leak of VM's binary stats FD

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20241220013906.3518334-2-seanjc@google.com>
Date: Thu, 19 Dec 2024 17:38:59 -0800
From: Sean Christopherson <seanjc@...gle.com>
To: Marc Zyngier <maz@...nel.org>, Oliver Upton <oliver.upton@...ux.dev>, 
	Anup Patel <anup@...infault.org>, Paul Walmsley <paul.walmsley@...ive.com>, 
	Palmer Dabbelt <palmer@...belt.com>, Albert Ou <aou@...s.berkeley.edu>, 
	Christian Borntraeger <borntraeger@...ux.ibm.com>, Janosch Frank <frankja@...ux.ibm.com>, 
	Claudio Imbrenda <imbrenda@...ux.ibm.com>, Sean Christopherson <seanjc@...gle.com>, 
	Paolo Bonzini <pbonzini@...hat.com>
Cc: linux-arm-kernel@...ts.infradead.org, kvmarm@...ts.linux.dev, 
	kvm@...r.kernel.org, kvm-riscv@...ts.infradead.org, 
	linux-riscv@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: [PATCH 1/8] KVM: selftests: Fix mostly theoretical leak of VM's
 binary stats FD

When allocating and freeing a VM's cached binary stats info, check for a
NULL descriptor, not a '0' file descriptor, as '0' is a legal FD.  E.g. in
the unlikely scenario the kernel installs the stats FD at entry '0',
selftests would reallocate on the next __vm_get_stat() and/or fail to free
the stats in kvm_vm_free().

Fixes: 83f6e109f562 ("KVM: selftests: Cache binary stats metadata for duration of test")
Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 tools/testing/selftests/kvm/lib/kvm_util.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 33fefeb3ca44..91d295ef5d02 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -749,7 +749,7 @@ void kvm_vm_free(struct kvm_vm *vmp)
 		return;
 
 	/* Free cached stats metadata and close FD */
-	if (vmp->stats_fd) {
+	if (vmp->stats_desc) {
 		free(vmp->stats_desc);
 		close(vmp->stats_fd);
 	}
@@ -2218,7 +2218,7 @@ void __vm_get_stat(struct kvm_vm *vm, const char *stat_name, uint64_t *data,
 	size_t size_desc;
 	int i;
 
-	if (!vm->stats_fd) {
+	if (!vm->stats_desc) {
 		vm->stats_fd = vm_get_stats_fd(vm);
 		read_stats_header(vm->stats_fd, &vm->stats_header);
 		vm->stats_desc = read_stats_descriptors(vm->stats_fd,
-- 
2.47.1.613.gc27f4b7a9f-goog