[CIFS] Fix potential NULL pointer usage if kzalloc fails

Potential problem was noticed by Cyrill Gorcunov

CC: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

2 files changed, 17 insertions, 12 deletions

diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c
index 1bf8cf522ad6..0356694b5cd0 100644
--- a/fs/cifs/cifs_debug.c
+++ b/fs/cifs/cifs_debug.c
@@ -209,13 +209,15 @@ cifs_debug_data_read(char *buf, char **beginBuffer, off_t offset,
                 i++;
                 tcon = list_entry(tmp, struct cifsTconInfo, cifsConnectionList);
                 dev_type = le32_to_cpu(tcon->fsDevInfo.DeviceType);
-                length =
-                    sprintf(buf,
-                            "\n%d) %s Uses: %d Type: %s DevInfo: 0x%x "
-                            "Attributes: 0x%x\nPathComponentMax: %d Status: %d",
-                            i, tcon->treeName,
-                            atomic_read(&tcon->useCount),
-                            tcon->nativeFileSystem,
+                length = sprintf(buf, "\n%d) %s Uses: %d ", i,
+                                 tcon->treeName, atomic_read(&tcon->useCount));
+                buf += length;
+                if (tcon->nativeFileSystem) {
+                        length = sprintf("Type: %s ", tcon->nativeFileSystem);
+                        buf += length;
+                }
+                length = sprintf(buf, "DevInfo: 0x%x Attributes: 0x%x"
+                                 "\nPathComponentMax: %d Status: %d",
                             le32_to_cpu(tcon->fsDevInfo.DeviceCharacteristics),
                             le32_to_cpu(tcon->fsAttrInfo.Attributes),
                             le32_to_cpu(tcon->fsAttrInfo.MaxPathNameComponentLength),
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index a83684d8eb5a..5f2ec1946776 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -3386,9 +3386,11 @@ CIFSTCon(unsigned int xid, struct cifsSesInfo *ses,
                                 kfree(tcon->nativeFileSystem);
                                 tcon->nativeFileSystem =
                                     kzalloc(length + 2, GFP_KERNEL);
-                                cifs_strfromUCS_le(tcon->nativeFileSystem,
-                                                   (__le16 *) bcc_ptr,
-                                                   length, nls_codepage);
+                                if (tcon->nativeFileSystem)
+                                        cifs_strfromUCS_le(
+                                                tcon->nativeFileSystem,
+                                                (__le16 *) bcc_ptr,
+                                                length, nls_codepage);
                                 bcc_ptr += 2 * length;
                                 bcc_ptr[0] = 0; /* null terminate the string */
                                 bcc_ptr[1] = 0;
@@ -3403,8 +3405,9 @@ CIFSTCon(unsigned int xid, struct cifsSesInfo *ses,
                                 kfree(tcon->nativeFileSystem);
                                 tcon->nativeFileSystem =
                                     kzalloc(length + 1, GFP_KERNEL);
-                                strncpy(tcon->nativeFileSystem, bcc_ptr,
-                                        length);
+                                if (tcon->nativeFileSystem)
+                                        strncpy(tcon->nativeFileSystem, bcc_ptr,
+                                                length);
                         }
                         /* else do not bother copying these information fields*/
                 }