From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f44.google.com (mail-pj1-f44.google.com [209.85.216.44]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2088E49883 for ; Mon, 18 Dec 2023 15:40:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-pj1-f44.google.com with SMTP id 98e67ed59e1d1-28b436f6cb9so2346213a91.3 for ; Mon, 18 Dec 2023 07:40:29 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702914029; x=1703518829; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=C1SfKyCK5+sHX3Wr7uZgrIDoFHfOUO1B8iPfaLe8ivE=; b=Be12kyODHhP+6kZ19uU/E9XbPAHQcw0EYV8fb1++1EQi+nThLfN+mm3BlFXRJSL/RV eFZ3c0qqECN6d0GCgCCbrARkFtwdr3tuiW9ZH7v9Pc8Gy7YyM+rWjR+GJ15SlWG62zUh 62G+q4DGLtjqmf10bmY/8TT+ezNdxo+QZJVUb7phtBk8EtBPGfDtbjA52ac9nIxMB7BB fNtnNhQYJha/AdrqSitFVApv5jwMhjXUodoTHG5nMMF/ALlZn/Wb8ziQoY3ub7mdUcvu HWMAAuvAotLy6sbcWgkojXbi9Bn3akd8w3GynkF0NgHOxV5+X0TGW7wGFLE4evcQeKRo WreA== X-Gm-Message-State: AOJu0YxpJJXJC6zKG2DlqoiMRsyLVJQFq9Xm5llVu3/ifX4e1hBdVdK4 MPHnaSWqCggX17bykpy9vTo= X-Google-Smtp-Source: AGHT+IF+4C0fYFXebUI1Ez5UeE2rL2Cq8yCLDMt/UZUK5oadRq+TQ96fxMSqDbQRRoOyQQR5g6H6hg== X-Received: by 2002:a17:90a:e554:b0:28b:4669:3cd1 with SMTP id ei20-20020a17090ae55400b0028b46693cd1mr1667470pjb.96.1702914029327; Mon, 18 Dec 2023 07:40:29 -0800 (PST) Received: from localhost.localdomain ([110.14.71.32]) by smtp.gmail.com with ESMTPSA id fs7-20020a17090af28700b00286ed94466dsm5613041pjb.32.2023.12.18.07.40.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 Dec 2023 07:40:28 -0800 (PST) From: Namjae Jeon To: gregkh@linuxfoundation.org, stable@vger.kernel.org Cc: smfrench@gmail.com, Namjae Jeon , Per Forlin , Steve French Subject: [PATCH 5.15.y 096/154] ksmbd: fix UAF issue from opinfo->conn Date: Tue, 19 Dec 2023 00:33:56 +0900 Message-Id: <20231218153454.8090-97-linkinjeon@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20231218153454.8090-1-linkinjeon@kernel.org> References: <20231218153454.8090-1-linkinjeon@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit [ Upstream commit 36322523dddb11107e9f7f528675a0dec2536103 ] If opinfo->conn is another connection and while ksmbd send oplock break request to cient on current connection, The connection for opinfo->conn can be disconnect and conn could be freed. When sending oplock break request, this ksmbd_conn can be used and cause user-after-free issue. When getting opinfo from the list, ksmbd check connection is being released. If it is not released, Increase ->r_count to wait that connection is freed. Cc: stable@vger.kernel.org Reported-by: Per Forlin Tested-by: Per Forlin Signed-off-by: Namjae Jeon Signed-off-by: Steve French --- fs/ksmbd/oplock.c | 72 +++++++++++++++++++++++++++++++---------------- 1 file changed, 47 insertions(+), 25 deletions(-) diff --git a/fs/ksmbd/oplock.c b/fs/ksmbd/oplock.c index 919c598a9d66..28c7f2193fb3 100644 --- a/fs/ksmbd/oplock.c +++ b/fs/ksmbd/oplock.c @@ -157,13 +157,42 @@ static struct oplock_info *opinfo_get_list(struct ksmbd_inode *ci) rcu_read_lock(); opinfo = list_first_or_null_rcu(&ci->m_op_list, struct oplock_info, op_entry); - if (opinfo && !atomic_inc_not_zero(&opinfo->refcount)) - opinfo = NULL; + if (opinfo) { + if (!atomic_inc_not_zero(&opinfo->refcount)) + opinfo = NULL; + else { + atomic_inc(&opinfo->conn->r_count); + if (ksmbd_conn_releasing(opinfo->conn)) { + atomic_dec(&opinfo->conn->r_count); + atomic_dec(&opinfo->refcount); + opinfo = NULL; + } + } + } + rcu_read_unlock(); return opinfo; } +static void opinfo_conn_put(struct oplock_info *opinfo) +{ + struct ksmbd_conn *conn; + + if (!opinfo) + return; + + conn = opinfo->conn; + /* + * Checking waitqueue to dropping pending requests on + * disconnection. waitqueue_active is safe because it + * uses atomic operation for condition. + */ + if (!atomic_dec_return(&conn->r_count) && waitqueue_active(&conn->r_count_q)) + wake_up(&conn->r_count_q); + opinfo_put(opinfo); +} + void opinfo_put(struct oplock_info *opinfo) { if (!atomic_dec_and_test(&opinfo->refcount)) @@ -666,13 +695,6 @@ static void __smb2_oplock_break_noti(struct work_struct *wk) out: ksmbd_free_work_struct(work); - /* - * Checking waitqueue to dropping pending requests on - * disconnection. waitqueue_active is safe because it - * uses atomic operation for condition. - */ - if (!atomic_dec_return(&conn->r_count) && waitqueue_active(&conn->r_count_q)) - wake_up(&conn->r_count_q); } /** @@ -706,7 +728,6 @@ static int smb2_oplock_break_noti(struct oplock_info *opinfo) work->conn = conn; work->sess = opinfo->sess; - atomic_inc(&conn->r_count); if (opinfo->op_state == OPLOCK_ACK_WAIT) { INIT_WORK(&work->work, __smb2_oplock_break_noti); ksmbd_queue_work(work); @@ -776,13 +797,6 @@ static void __smb2_lease_break_noti(struct work_struct *wk) out: ksmbd_free_work_struct(work); - /* - * Checking waitqueue to dropping pending requests on - * disconnection. waitqueue_active is safe because it - * uses atomic operation for condition. - */ - if (!atomic_dec_return(&conn->r_count) && waitqueue_active(&conn->r_count_q)) - wake_up(&conn->r_count_q); } /** @@ -822,7 +836,6 @@ static int smb2_lease_break_noti(struct oplock_info *opinfo) work->conn = conn; work->sess = opinfo->sess; - atomic_inc(&conn->r_count); if (opinfo->op_state == OPLOCK_ACK_WAIT) { list_for_each_safe(tmp, t, &opinfo->interim_list) { struct ksmbd_work *in_work; @@ -1144,8 +1157,10 @@ int smb_grant_oplock(struct ksmbd_work *work, int req_op_level, u64 pid, } prev_opinfo = opinfo_get_list(ci); if (!prev_opinfo || - (prev_opinfo->level == SMB2_OPLOCK_LEVEL_NONE && lctx)) + (prev_opinfo->level == SMB2_OPLOCK_LEVEL_NONE && lctx)) { + opinfo_conn_put(prev_opinfo); goto set_lev; + } prev_op_has_lease = prev_opinfo->is_lease; if (prev_op_has_lease) prev_op_state = prev_opinfo->o_lease->state; @@ -1153,19 +1168,19 @@ int smb_grant_oplock(struct ksmbd_work *work, int req_op_level, u64 pid, if (share_ret < 0 && prev_opinfo->level == SMB2_OPLOCK_LEVEL_EXCLUSIVE) { err = share_ret; - opinfo_put(prev_opinfo); + opinfo_conn_put(prev_opinfo); goto err_out; } if (prev_opinfo->level != SMB2_OPLOCK_LEVEL_BATCH && prev_opinfo->level != SMB2_OPLOCK_LEVEL_EXCLUSIVE) { - opinfo_put(prev_opinfo); + opinfo_conn_put(prev_opinfo); goto op_break_not_needed; } list_add(&work->interim_entry, &prev_opinfo->interim_list); err = oplock_break(prev_opinfo, SMB2_OPLOCK_LEVEL_II); - opinfo_put(prev_opinfo); + opinfo_conn_put(prev_opinfo); if (err == -ENOENT) goto set_lev; /* Check all oplock was freed by close */ @@ -1228,14 +1243,14 @@ static void smb_break_all_write_oplock(struct ksmbd_work *work, return; if (brk_opinfo->level != SMB2_OPLOCK_LEVEL_BATCH && brk_opinfo->level != SMB2_OPLOCK_LEVEL_EXCLUSIVE) { - opinfo_put(brk_opinfo); + opinfo_conn_put(brk_opinfo); return; } brk_opinfo->open_trunc = is_trunc; list_add(&work->interim_entry, &brk_opinfo->interim_list); oplock_break(brk_opinfo, SMB2_OPLOCK_LEVEL_II); - opinfo_put(brk_opinfo); + opinfo_conn_put(brk_opinfo); } /** @@ -1263,6 +1278,13 @@ void smb_break_all_levII_oplock(struct ksmbd_work *work, struct ksmbd_file *fp, list_for_each_entry_rcu(brk_op, &ci->m_op_list, op_entry) { if (!atomic_inc_not_zero(&brk_op->refcount)) continue; + + atomic_inc(&brk_op->conn->r_count); + if (ksmbd_conn_releasing(brk_op->conn)) { + atomic_dec(&brk_op->conn->r_count); + continue; + } + rcu_read_unlock(); if (brk_op->is_lease && (brk_op->o_lease->state & (~(SMB2_LEASE_READ_CACHING_LE | @@ -1292,7 +1314,7 @@ void smb_break_all_levII_oplock(struct ksmbd_work *work, struct ksmbd_file *fp, brk_op->open_trunc = is_trunc; oplock_break(brk_op, SMB2_OPLOCK_LEVEL_NONE); next: - opinfo_put(brk_op); + opinfo_conn_put(brk_op); rcu_read_lock(); } rcu_read_unlock(); -- 2.25.1