From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8FA3D42376B; Sat, 12 Sep 2026 11:47:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789213662; cv=none; b=oPkRVknn+Onhozs/hU203EuSyum8EV8qWq1JDznYI3JOT+eIwPqgJ/FsIGAq53O7N5tLD7HFGm1BmXKKEHYbUq4oTR8XM8xmo2GEhVJzNgyV9YRm4zHhDjdsIJ1UeP9+X7YW7iaGkPHlbibvVKwF/Kj0ui7NUV1UiJvWdnJASjk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789213662; c=relaxed/simple; bh=VXcg1ALZ7D1OIx2E+6knNTSwnfeDyupi8QHCMjLxgRA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bJ13ixPhsEiqZ4DtdLkMBKWfbGPfwzRk6CvZeWXCDbqAJX2eBV7VfCdK/9EknV7NQnuBWqxYD7l6r1Kt8J2b+wO0HpExTCD39yt4URbPHU+SKy8B4d2r9XeAqVmHWBFk786ed8Fs/M6tWSfwrm8Fbxh3FvIHhAP7JcNNTSthLVA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=NMgtFMlp; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="NMgtFMlp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5C25F1F00893; Sat, 12 Sep 2026 11:47:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789213659; bh=283DMkl0/YCwmnUKresD8b4VF2XLddgomQtVIGAp+M0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=NMgtFMlpNZY0hcQNw3OC9a4F0vnmebJyhPjkJyfkua2uRl6GqrhhhJn7HW2X3/+1R lPRRQzMsr/OVEbJ2MbaGDe9RW7x0/EzzGb/6CKLHInwc1qoKOg+FjYt0gSdksCvj2G SgnoiCaHc/xPe3SGBGOZQQJEqOA4sYVcjw9INo1Y= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Christian Borntraeger , Matthew Rosato , Claudio Imbrenda Subject: [PATCH 6.12 0166/1376] KVM: s390: Fix old_data leak in guest debug error path Date: Sat, 12 Sep 2026 08:43:12 +0200 Message-ID: <20260912065611.250863024@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065607.535295758@linuxfoundation.org> References: <20260912065607.535295758@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Christian Borntraeger commit aa9c8e8baf1e765fa65b93212522c636f25d846f upstream. __import_wp_info() allocates a per-watchpoint old_data buffer to back up the original guest memory contents. If a later watchpoint of the same KVM_SET_GUEST_DEBUG request fails to import, kvm_s390_import_bp_data() jumps to the error label, which frees the wp_info array but not the old_data buffers of the entries that were imported successfully. Up to MAX_BP_COUNT - 1 buffers of up to MAX_WP_SIZE bytes are leaked per failed request, and the request can be repeated. Create error handling for cleaning up all created old_data memory areas. Fixes: 27291e2165b6 ("KVM: s390: hardware support for guest debugging") Cc: stable@vger.kernel.org Signed-off-by: Christian Borntraeger Reviewed-by: Matthew Rosato Reviewed-by: Claudio Imbrenda Signed-off-by: Claudio Imbrenda Message-ID: <20260805110455.7200-6-borntraeger@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman --- arch/s390/kvm/guestdbg.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/arch/s390/kvm/guestdbg.c +++ b/arch/s390/kvm/guestdbg.c @@ -256,7 +256,7 @@ int kvm_s390_import_bp_data(struct kvm_v ret = __import_wp_info(vcpu, &bp_data[i], &wp_info[nr_wp]); if (ret) - goto error; + goto error_wp; nr_wp++; break; case KVM_HW_BP: @@ -273,6 +273,10 @@ int kvm_s390_import_bp_data(struct kvm_v vcpu->arch.guestdbg.hw_wp_info = wp_info; kfree(bp_data); return 0; + +error_wp: + while (nr_wp--) + kfree(wp_info[nr_wp].old_data); error: kfree(bp_data); kfree(wp_info);