From: Samuel Cabrero <scabrero@suse.de>
Date: Tue, 15 Dec 2020 17:46:56 +0100
Subject: [PATCH] cifs: Fix some error pointers handling detected by static
checker
Git-commit: 09a8361e3b681ef6b56cc56f7b2905b4455d6774
Patch-mainline: v5.11-rc1
References: bsc#1192606
* 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: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Samuel Cabrero <scabrero@suse.de>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Enzo Matsumiya <ematsumiya@suse.de>
---
fs/cifs/cifs_swn.c | 21 +++++++++++----------
1 file changed, 11 insertions(+), 10 deletions(-)
diff --git a/fs/cifs/cifs_swn.c b/fs/cifs/cifs_swn.c
index a172769c239f..69b7571010a6 100644
--- a/fs/cifs/cifs_swn.c
+++ b/fs/cifs/cifs_swn.c
@@ -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(®->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);
--
2.33.1