cifs: store password in tcon

cifs: store password in tcon

Each tcon has its own password for share-level security. Store it in
the tcon and wipe it clean and free it when freeing the tcon. When
doing the tree connect with share-level security, use the tcon password
instead of the session password.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

3 files changed, 23 insertions, 7 deletions

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 0fb934d3623b..94c1ca0ec953 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -242,6 +242,7 @@ struct cifsTconInfo {
         struct cifsSesInfo *ses;        /* pointer to session associated with */
         char treeName[MAX_TREE_SIZE + 1]; /* UNC name of resource in ASCII */
         char *nativeFileSystem;
+        char *password;         /* for share-level security */
         __u16 tid;              /* The 2 byte tree id */
         __u16 Flags;            /* optional support bits */
         enum statusEnum tidStatus;
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 3a84a375cb6f..3caadf12d76d 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -2282,9 +2282,12 @@ cifs_mount(struct super_block *sb, struct cifs_sb_info *cifs_sb,
 
                 /* volume_info->password freed at unmount */
                 if (volume_info->password) {
-                        pSesInfo->password = volume_info->password;
-                        /* set to NULL to prevent freeing on exit */
-                        volume_info->password = NULL;
+                        pSesInfo->password = kstrdup(volume_info->password,
+                                                     GFP_KERNEL);
+                        if (!pSesInfo->password) {
+                                rc = -ENOMEM;
+                                goto mount_fail_check;
+                        }
                 }
                 if (volume_info->username)
                         strncpy(pSesInfo->userName, volume_info->username,
@@ -2324,7 +2327,16 @@ cifs_mount(struct super_block *sb, struct cifs_sb_info *cifs_sb,
                                 rc = -ENOMEM;
                                 goto mount_fail_check;
                         }
+
                         tcon->ses = pSesInfo;
+                        if (volume_info->password) {
+                                tcon->password = kstrdup(volume_info->password,
+                                                         GFP_KERNEL);
+                                if (!tcon->password) {
+                                        rc = -ENOMEM;
+                                        goto mount_fail_check;
+                                }
+                        }
 
                         /* check for null share name ie connect to dfs root */
                         if ((strchr(volume_info->UNC + 3, '\\') == NULL)
@@ -3532,15 +3544,14 @@ CIFSTCon(unsigned int xid, struct cifsSesInfo *ses,
                    NTLMv2 password here) */
 #ifdef CONFIG_CIFS_WEAK_PW_HASH
                 if ((extended_security & CIFSSEC_MAY_LANMAN) &&
-                        (ses->server->secType == LANMAN))
-                        calc_lanman_hash(ses->password, ses->server->cryptKey,
+                    (ses->server->secType == LANMAN))
+                        calc_lanman_hash(tcon->password, ses->server->cryptKey,
                                          ses->server->secMode &
                                             SECMODE_PW_ENCRYPT ? true : false,
                                          bcc_ptr);
                 else
 #endif /* CIFS_WEAK_PW_HASH */
-                SMBNTencrypt(ses->password,
-                             ses->server->cryptKey,
+                SMBNTencrypt(tcon->password, ses->server->cryptKey,
                              bcc_ptr);
 
                 bcc_ptr += CIFS_SESS_KEY_SIZE;
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index 7c3f4b9230d7..a0513605d7e3 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -132,6 +132,10 @@ tconInfoFree(struct cifsTconInfo *buf_to_free)
         }
         atomic_dec(&tconInfoAllocCount);
         kfree(buf_to_free->nativeFileSystem);
+        if (buf_to_free->password) {
+                memset(buf_to_free->password, 0, strlen(buf_to_free->password));
+                kfree(buf_to_free->password);
+        }
         kfree(buf_to_free);
 }