Patch "ksmbd: add channel rwlock" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    ksmbd: add channel rwlock

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ksmbd-add-channel-rwlock.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 7584fe5f147216d18ccb3b13f90cdeaad6cd6ecd
Author: Namjae Jeon <linkinjeon@xxxxxxxxxx>
Date:   Fri Jul 22 10:15:57 2022 +0900

    ksmbd: add channel rwlock
    
    [ Upstream commit 8e06b31e348107c5d78e2c90bb7e69388cb97fb6 ]
    
    Add missing rwlock for channel list in session.
    
    Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxxx>
    Reviewed-by: Hyunchul Lee <hyc.lee@xxxxxxxxx>
    Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
    Stable-dep-of: 7b4323373d84 ("ksmbd: fix deadlock in ksmbd_find_crypto_ctx()")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/ksmbd/mgmt/user_session.c b/fs/ksmbd/mgmt/user_session.c
index 8fe08df668582..0c7b5335c12af 100644
--- a/fs/ksmbd/mgmt/user_session.c
+++ b/fs/ksmbd/mgmt/user_session.c
@@ -32,11 +32,13 @@ static void free_channel_list(struct ksmbd_session *sess)
 {
 	struct channel *chann, *tmp;
 
+	write_lock(&sess->chann_lock);
 	list_for_each_entry_safe(chann, tmp, &sess->ksmbd_chann_list,
 				 chann_list) {
 		list_del(&chann->chann_list);
 		kfree(chann);
 	}
+	write_unlock(&sess->chann_lock);
 }
 
 static void __session_rpc_close(struct ksmbd_session *sess,
@@ -305,6 +307,7 @@ static struct ksmbd_session *__session_create(int protocol)
 	INIT_LIST_HEAD(&sess->rpc_handle_list);
 	sess->sequence_number = 1;
 	atomic_set(&sess->refcnt, 1);
+	rwlock_init(&sess->chann_lock);
 
 	switch (protocol) {
 	case CIFDS_SESSION_FLAG_SMB2:
diff --git a/fs/ksmbd/mgmt/user_session.h b/fs/ksmbd/mgmt/user_session.h
index 8b08189be3fc2..1ec659f0151bf 100644
--- a/fs/ksmbd/mgmt/user_session.h
+++ b/fs/ksmbd/mgmt/user_session.h
@@ -48,6 +48,7 @@ struct ksmbd_session {
 	char				sess_key[CIFS_KEY_SIZE];
 
 	struct hlist_node		hlist;
+	rwlock_t			chann_lock;
 	struct list_head		ksmbd_chann_list;
 	struct xarray			tree_conns;
 	struct ida			tree_conn_ida;
diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index d41995f89befe..e17f7a5dd9974 100644
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -1525,7 +1525,9 @@ static int ntlm_authenticate(struct ksmbd_work *work)
 
 binding_session:
 	if (conn->dialect >= SMB30_PROT_ID) {
+		read_lock(&sess->chann_lock);
 		chann = lookup_chann_list(sess, conn);
+		read_unlock(&sess->chann_lock);
 		if (!chann) {
 			chann = kmalloc(sizeof(struct channel), GFP_KERNEL);
 			if (!chann)
@@ -1533,7 +1535,9 @@ static int ntlm_authenticate(struct ksmbd_work *work)
 
 			chann->conn = conn;
 			INIT_LIST_HEAD(&chann->chann_list);
+			write_lock(&sess->chann_lock);
 			list_add(&chann->chann_list, &sess->ksmbd_chann_list);
+			write_unlock(&sess->chann_lock);
 		}
 	}
 
@@ -1608,7 +1612,9 @@ static int krb5_authenticate(struct ksmbd_work *work)
 	}
 
 	if (conn->dialect >= SMB30_PROT_ID) {
+		read_lock(&sess->chann_lock);
 		chann = lookup_chann_list(sess, conn);
+		read_unlock(&sess->chann_lock);
 		if (!chann) {
 			chann = kmalloc(sizeof(struct channel), GFP_KERNEL);
 			if (!chann)
@@ -1616,7 +1622,9 @@ static int krb5_authenticate(struct ksmbd_work *work)
 
 			chann->conn = conn;
 			INIT_LIST_HEAD(&chann->chann_list);
+			write_lock(&sess->chann_lock);
 			list_add(&chann->chann_list, &sess->ksmbd_chann_list);
+			write_unlock(&sess->chann_lock);
 		}
 	}
 
@@ -8388,10 +8396,14 @@ int smb3_check_sign_req(struct ksmbd_work *work)
 	if (le16_to_cpu(hdr->Command) == SMB2_SESSION_SETUP_HE) {
 		signing_key = work->sess->smb3signingkey;
 	} else {
+		read_lock(&work->sess->chann_lock);
 		chann = lookup_chann_list(work->sess, conn);
-		if (!chann)
+		if (!chann) {
+			read_unlock(&work->sess->chann_lock);
 			return 0;
+		}
 		signing_key = chann->smb3signingkey;
+		read_unlock(&work->sess->chann_lock);
 	}
 
 	if (!signing_key) {
@@ -8451,10 +8463,14 @@ void smb3_set_sign_rsp(struct ksmbd_work *work)
 	    le16_to_cpu(hdr->Command) == SMB2_SESSION_SETUP_HE) {
 		signing_key = work->sess->smb3signingkey;
 	} else {
+		read_lock(&work->sess->chann_lock);
 		chann = lookup_chann_list(work->sess, work->conn);
-		if (!chann)
+		if (!chann) {
+			read_unlock(&work->sess->chann_lock);
 			return;
+		}
 		signing_key = chann->smb3signingkey;
+		read_unlock(&work->sess->chann_lock);
 	}
 
 	if (!signing_key)