cifs: we do not allow changing username/password/unc/... during remount
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
diff --git a/fs/cifs/fs_context.c b/fs/cifs/fs_context.c
index 18b469f..b807f8a 100644
--- a/fs/cifs/fs_context.c
+++ b/fs/cifs/fs_context.c
@@ -632,10 +632,51 @@ static int smb3_verify_reconfigure_ctx(struct smb3_fs_context *new_ctx,
cifs_dbg(VFS, "can not change sec during remount\n");
return -EINVAL;
}
+ if (new_ctx->multiuser != old_ctx->multiuser) {
+ cifs_dbg(VFS, "can not change multiuser during remount\n");
+ return -EINVAL;
+ }
+ if (new_ctx->UNC &&
+ (!old_ctx->UNC || strcmp(new_ctx->UNC, old_ctx->UNC))) {
+ cifs_dbg(VFS, "can not change UNC during remount\n");
+ return -EINVAL;
+ }
+ if (new_ctx->username &&
+ (!old_ctx->username || strcmp(new_ctx->username, old_ctx->username))) {
+ cifs_dbg(VFS, "can not change username during remount\n");
+ return -EINVAL;
+ }
+ if (new_ctx->password &&
+ (!old_ctx->password || strcmp(new_ctx->password, old_ctx->password))) {
+ cifs_dbg(VFS, "can not change password during remount\n");
+ return -EINVAL;
+ }
+ if (new_ctx->domainname &&
+ (!old_ctx->domainname || strcmp(new_ctx->domainname, old_ctx->domainname))) {
+ cifs_dbg(VFS, "can not change domainname during remount\n");
+ return -EINVAL;
+ }
+ if (new_ctx->nodename &&
+ (!old_ctx->nodename || strcmp(new_ctx->nodename, old_ctx->nodename))) {
+ cifs_dbg(VFS, "can not change nodename during remount\n");
+ return -EINVAL;
+ }
+ if (new_ctx->iocharset &&
+ (!old_ctx->iocharset || strcmp(new_ctx->iocharset, old_ctx->iocharset))) {
+ cifs_dbg(VFS, "can not change iocharset during remount\n");
+ return -EINVAL;
+ }
return 0;
}
+#define STEAL_STRING(cifs_sb, ctx, field) \
+do { \
+ kfree(ctx->field); \
+ ctx->field = cifs_sb->ctx->field; \
+ cifs_sb->ctx->field = NULL; \
+} while (0)
+
static int smb3_reconfigure(struct fs_context *fc)
{
struct smb3_fs_context *ctx = smb3_fc2context(fc);
@@ -648,10 +689,16 @@ static int smb3_reconfigure(struct fs_context *fc)
return rc;
/*
- * Steal the UNC from the old and to be destroyed context.
+ * We can not change UNC/username/password/domainname/nodename/iocharset
+ * during reconnect so ignore what we have in the new context and
+ * just use what we already have in cifs_sb->ctx.
*/
- ctx->UNC = cifs_sb->ctx->UNC;
- cifs_sb->ctx->UNC = NULL;
+ STEAL_STRING(cifs_sb, ctx, UNC);
+ STEAL_STRING(cifs_sb, ctx, username);
+ STEAL_STRING(cifs_sb, ctx, password);
+ STEAL_STRING(cifs_sb, ctx, domainname);
+ STEAL_STRING(cifs_sb, ctx, nodename);
+ STEAL_STRING(cifs_sb, ctx, iocharset);
smb3_cleanup_fs_context_contents(cifs_sb->ctx);
rc = smb3_fs_context_dup(cifs_sb->ctx, ctx);