Commit 09a8361e authored by Samuel Cabrero's avatar Samuel Cabrero Committed by Steve French
Browse files

cifs: Fix some error pointers handling detected by static checker 



* extract_hostname() and extract_sharename() never return NULL, so
  use IS_ERR() instead of IS_ERR_OR_NULL() in cifs_find_swn_reg(). If
  any of these functions return an error, then return an error pointer
  instead of NULL.
* Change cifs_find_swn_reg() function to always return a valid pointer
  or an error pointer, instead of returning NULL if the registration
  is not found.
* Finally update cifs_find_swn_reg() callers to check for -EEXIST
  instead of NULL.
* In cifs_get_swn_reg() the swnreg idr mutex was not unlocked in the
  error path of cifs_find_swn_reg() call.

Reported-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarSamuel Cabrero <scabrero@suse.de>
Reviewed-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent dd538034

fs/cifs/cifs_swn.c

+11 −10
Original line number Diff line number Diff line
@@ -259,24 +259,24 @@ static struct cifs_swn_reg *cifs_find_swn_reg(struct cifs_tcon *tcon) 
	const char *net_name;



	net_name = extract_hostname(tcon->treeName);

	if (IS_ERR_OR_NULL(net_name)) {

	if (IS_ERR(net_name)) {

		int ret;



		ret = PTR_ERR(net_name);

		cifs_dbg(VFS, "%s: failed to extract host name from target '%s': %d\n",

				__func__, tcon->treeName, ret);

		return NULL;

		return ERR_PTR(-EINVAL);

	}



	share_name = extract_sharename(tcon->treeName);

	if (IS_ERR_OR_NULL(share_name)) {

	if (IS_ERR(share_name)) {

		int ret;



		ret = PTR_ERR(net_name);

		cifs_dbg(VFS, "%s: failed to extract share name from target '%s': %d\n",

				__func__, tcon->treeName, ret);

		kfree(net_name);

		return NULL;

		return ERR_PTR(-EINVAL);

	}



	idr_for_each_entry(&cifs_swnreg_idr, swnreg, id) {
@@ -299,7 +299,7 @@ static struct cifs_swn_reg *cifs_find_swn_reg(struct cifs_tcon *tcon) 
	kfree(net_name);

	kfree(share_name);



	return NULL;

	return ERR_PTR(-EEXIST);

}



/*
@@ -315,12 +315,13 @@ static struct cifs_swn_reg *cifs_get_swn_reg(struct cifs_tcon *tcon) 


	/* Check if we are already registered for this network and share names */

	reg = cifs_find_swn_reg(tcon);

	if (IS_ERR(reg)) {

		return reg;

	} else if (reg != NULL) {

	if (!IS_ERR(reg)) {

		kref_get(&reg->ref_count);

		mutex_unlock(&cifs_swnreg_idr_mutex);

		return reg;

	} else if (PTR_ERR(reg) != -EEXIST) {

		mutex_unlock(&cifs_swnreg_idr_mutex);

		return reg;

	}



	reg = kmalloc(sizeof(struct cifs_swn_reg), GFP_ATOMIC);
@@ -630,9 +631,9 @@ int cifs_swn_unregister(struct cifs_tcon *tcon) 
	mutex_lock(&cifs_swnreg_idr_mutex);



	swnreg = cifs_find_swn_reg(tcon);

	if (swnreg == NULL) {

	if (IS_ERR(swnreg)) {

		mutex_unlock(&cifs_swnreg_idr_mutex);

		return -EEXIST;

		return PTR_ERR(swnreg);

	}



	mutex_unlock(&cifs_swnreg_idr_mutex);

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