From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 876B52853FF; Wed, 23 Apr 2025 15:00:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745420411; cv=none; b=HG6HHljdkezylL0fdJqZHCrqh7hwHIFGl5Bqcacsa90xunnR9r2x424VVV9oYvqGp4XKA5RI902Av24a8YXrgH42JPED//mcgmho8fHzUyjqXcjqJHiOUWecgb+TzNQYuo229xdljblAgTJvt5Xppb0iKul9/PR5VdBLSBwp01I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745420411; c=relaxed/simple; bh=9ChyvPN8c1vIKpvUnBh13sVga4V3Q3JSE0+k/EVPI8g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Ld5xDXoQI4ZdvhfTuTPPs6jHnACHhoaaocWB+SUwSl0Yu2EtoaQFi6tfSwAasL4aqyegU4qZ7S6kwu2MjmfItelp1qXrgTDRrZKg/Bf4lseEWzYSvjimkNYsgzNVwlvRG3w5jGhl+MUKGMj2OdPhEPAQWz2pNJzOcLz6lLn2GGQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=mN7HFEcm; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="mN7HFEcm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AF23DC4CEE3; Wed, 23 Apr 2025 15:00:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1745420411; bh=9ChyvPN8c1vIKpvUnBh13sVga4V3Q3JSE0+k/EVPI8g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mN7HFEcm3OMmKQ/5XHQ1nn4Yo4ZXQREIElwaaT5FX5mkWPzetWPH5/RwAVjfu178U wsC/x5KLLBeB+9cG4zgvMj/KMSd+YtUnl+g9+xftHO3LauUa27DezUXFQ0SU0ppMKc cfS9mtCODP6Q53LYHfZ4C1mWVlwC3QRvfWmVydt8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sean Heelan , Namjae Jeon , Steve French Subject: [PATCH 6.12 122/223] ksmbd: Fix dangling pointer in krb_authenticate Date: Wed, 23 Apr 2025 16:43:14 +0200 Message-ID: <20250423142622.076303781@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250423142617.120834124@linuxfoundation.org> References: <20250423142617.120834124@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org 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: Sean Heelan commit 1e440d5b25b7efccb3defe542a73c51005799a5f upstream. krb_authenticate frees sess->user and does not set the pointer to NULL. It calls ksmbd_krb5_authenticate to reinitialise sess->user but that function may return without doing so. If that happens then smb2_sess_setup, which calls krb_authenticate, will be accessing free'd memory when it later uses sess->user. Cc: stable@vger.kernel.org Signed-off-by: Sean Heelan Acked-by: Namjae Jeon Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/smb/server/smb2pdu.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -1599,8 +1599,10 @@ static int krb5_authenticate(struct ksmb if (prev_sess_id && prev_sess_id != sess->id) destroy_previous_session(conn, sess->user, prev_sess_id); - if (sess->state == SMB2_SESSION_VALID) + if (sess->state == SMB2_SESSION_VALID) { ksmbd_free_user(sess->user); + sess->user = NULL; + } retval = ksmbd_krb5_authenticate(sess, in_blob, in_len, out_blob, &out_len);