15 files changed, 71 insertions, 30 deletions

diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index d1c833c321b9..7b6bfcbf801c 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -479,7 +479,7 @@ static int ceph_show_options(struct seq_file *m, struct dentry *root)
         if (fsopt->max_readdir_bytes != CEPH_MAX_READDIR_BYTES_DEFAULT)
                 seq_printf(m, ",readdir_max_bytes=%d", fsopt->max_readdir_bytes);
         if (strcmp(fsopt->snapdir_name, CEPH_SNAPDIRNAME_DEFAULT))
-                seq_printf(m, ",snapdirname=%s", fsopt->snapdir_name);
+                seq_show_option(m, "snapdirname", fsopt->snapdir_name);
 
         return 0;
 }
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 0a9fb6b53126..6a1119e87fbb 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -394,17 +394,17 @@ cifs_show_options(struct seq_file *s, struct dentry *root)
         struct sockaddr *srcaddr;
         srcaddr = (struct sockaddr *)&tcon->ses->server->srcaddr;
 
-        seq_printf(s, ",vers=%s", tcon->ses->server->vals->version_string);
+        seq_show_option(s, "vers", tcon->ses->server->vals->version_string);
         cifs_show_security(s, tcon->ses);
         cifs_show_cache_flavor(s, cifs_sb);
 
         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER)
                 seq_puts(s, ",multiuser");
         else if (tcon->ses->user_name)
-                seq_printf(s, ",username=%s", tcon->ses->user_name);
+                seq_show_option(s, "username", tcon->ses->user_name);
 
         if (tcon->ses->domainName)
-                seq_printf(s, ",domain=%s", tcon->ses->domainName);
+                seq_show_option(s, "domain", tcon->ses->domainName);
 
         if (srcaddr->sa_family != AF_UNSPEC) {
                 struct sockaddr_in *saddr4;
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index ee3878262a49..a63c7b0a10cf 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1776,10 +1776,10 @@ static inline void ext4_show_quota_options(struct seq_file *seq,
         }
 
         if (sbi->s_qf_names[USRQUOTA])
-                seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
+                seq_show_option(seq, "usrjquota", sbi->s_qf_names[USRQUOTA]);
 
         if (sbi->s_qf_names[GRPQUOTA])
-                seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
+                seq_show_option(seq, "grpjquota", sbi->s_qf_names[GRPQUOTA]);
 #endif
 }
 
diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index 2982445947e1..894fb01a91da 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -1334,11 +1334,11 @@ static int gfs2_show_options(struct seq_file *s, struct dentry *root)
         if (is_ancestor(root, sdp->sd_master_dir))
                 seq_puts(s, ",meta");
         if (args->ar_lockproto[0])
-                seq_printf(s, ",lockproto=%s", args->ar_lockproto);
+                seq_show_option(s, "lockproto", args->ar_lockproto);
         if (args->ar_locktable[0])
-                seq_printf(s, ",locktable=%s", args->ar_locktable);
+                seq_show_option(s, "locktable", args->ar_locktable);
         if (args->ar_hostdata[0])
-                seq_printf(s, ",hostdata=%s", args->ar_hostdata);
+                seq_show_option(s, "hostdata", args->ar_hostdata);
         if (args->ar_spectator)
                 seq_puts(s, ",spectator");
         if (args->ar_localflocks)
diff --git a/fs/hfs/super.c b/fs/hfs/super.c
index 55c03b9e9070..4574fdd3d421 100644
--- a/fs/hfs/super.c
+++ b/fs/hfs/super.c
@@ -136,9 +136,9 @@ static int hfs_show_options(struct seq_file *seq, struct dentry *root)
         struct hfs_sb_info *sbi = HFS_SB(root->d_sb);
 
         if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
-                seq_printf(seq, ",creator=%.4s", (char *)&sbi->s_creator);
+                seq_show_option_n(seq, "creator", (char *)&sbi->s_creator, 4);
         if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
-                seq_printf(seq, ",type=%.4s", (char *)&sbi->s_type);
+                seq_show_option_n(seq, "type", (char *)&sbi->s_type, 4);
         seq_printf(seq, ",uid=%u,gid=%u",
                         from_kuid_munged(&init_user_ns, sbi->s_uid),
                         from_kgid_munged(&init_user_ns, sbi->s_gid));
diff --git a/fs/hfsplus/options.c b/fs/hfsplus/options.c
index c90b72ee676d..bb806e58c977 100644
--- a/fs/hfsplus/options.c
+++ b/fs/hfsplus/options.c
@@ -218,9 +218,9 @@ int hfsplus_show_options(struct seq_file *seq, struct dentry *root)
         struct hfsplus_sb_info *sbi = HFSPLUS_SB(root->d_sb);
 
         if (sbi->creator != HFSPLUS_DEF_CR_TYPE)
-                seq_printf(seq, ",creator=%.4s", (char *)&sbi->creator);
+                seq_show_option_n(seq, "creator", (char *)&sbi->creator, 4);
         if (sbi->type != HFSPLUS_DEF_CR_TYPE)
-                seq_printf(seq, ",type=%.4s", (char *)&sbi->type);
+                seq_show_option_n(seq, "type", (char *)&sbi->type, 4);
         seq_printf(seq, ",umask=%o,uid=%u,gid=%u", sbi->umask,
                         from_kuid_munged(&init_user_ns, sbi->uid),
                         from_kgid_munged(&init_user_ns, sbi->gid));
diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c
index 059597b23f67..2ac99db3750e 100644
--- a/fs/hostfs/hostfs_kern.c
+++ b/fs/hostfs/hostfs_kern.c
@@ -260,7 +260,7 @@ static int hostfs_show_options(struct seq_file *seq, struct dentry *root)
         size_t offset = strlen(root_ino) + 1;
 
         if (strlen(root_path) > offset)
-                seq_printf(seq, ",%s", root_path + offset);
+                seq_show_option(seq, root_path + offset, NULL);
 
         if (append)
                 seq_puts(seq, ",append");
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index 3a9a1af39ad7..2de4c8a9340c 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -1563,8 +1563,8 @@ static int ocfs2_show_options(struct seq_file *s, struct dentry *root)
                 seq_printf(s, ",localflocks,");
 
         if (osb->osb_cluster_stack[0])
-                seq_printf(s, ",cluster_stack=%.*s", OCFS2_STACK_LABEL_LEN,
-                           osb->osb_cluster_stack);
+                seq_show_option_n(s, "cluster_stack", osb->osb_cluster_stack,
+                                  OCFS2_STACK_LABEL_LEN);
         if (opts & OCFS2_MOUNT_USRQUOTA)
                 seq_printf(s, ",usrquota");
         if (opts & OCFS2_MOUNT_GRPQUOTA)
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 7466ff339c66..79073d68b475 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -588,10 +588,10 @@ static int ovl_show_options(struct seq_file *m, struct dentry *dentry)
         struct super_block *sb = dentry->d_sb;
         struct ovl_fs *ufs = sb->s_fs_info;
 
-        seq_printf(m, ",lowerdir=%s", ufs->config.lowerdir);
+        seq_show_option(m, "lowerdir", ufs->config.lowerdir);
         if (ufs->config.upperdir) {
-                seq_printf(m, ",upperdir=%s", ufs->config.upperdir);
-                seq_printf(m, ",workdir=%s", ufs->config.workdir);
+                seq_show_option(m, "upperdir", ufs->config.upperdir);
+                seq_show_option(m, "workdir", ufs->config.workdir);
         }
         return 0;
 }
diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c
index 0e4cf728126f..4a62fe8cc3bf 100644
--- a/fs/reiserfs/super.c
+++ b/fs/reiserfs/super.c
@@ -714,18 +714,20 @@ static int reiserfs_show_options(struct seq_file *seq, struct dentry *root)
                 seq_puts(seq, ",acl");
 
         if (REISERFS_SB(s)->s_jdev)
-                seq_printf(seq, ",jdev=%s", REISERFS_SB(s)->s_jdev);
+                seq_show_option(seq, "jdev", REISERFS_SB(s)->s_jdev);
 
         if (journal->j_max_commit_age != journal->j_default_max_commit_age)
                 seq_printf(seq, ",commit=%d", journal->j_max_commit_age);
 
 #ifdef CONFIG_QUOTA
         if (REISERFS_SB(s)->s_qf_names[USRQUOTA])
-                seq_printf(seq, ",usrjquota=%s", REISERFS_SB(s)->s_qf_names[USRQUOTA]);
+                seq_show_option(seq, "usrjquota",
+                                REISERFS_SB(s)->s_qf_names[USRQUOTA]);
         else if (opts & (1 << REISERFS_USRQUOTA))
                 seq_puts(seq, ",usrquota");
         if (REISERFS_SB(s)->s_qf_names[GRPQUOTA])
-                seq_printf(seq, ",grpjquota=%s", REISERFS_SB(s)->s_qf_names[GRPQUOTA]);
+                seq_show_option(seq, "grpjquota",
+                                REISERFS_SB(s)->s_qf_names[GRPQUOTA]);
         else if (opts & (1 << REISERFS_GRPQUOTA))
                 seq_puts(seq, ",grpquota");
         if (REISERFS_SB(s)->s_jquota_fmt) {
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 1fb16562c159..bbd9b1f10ffb 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -511,9 +511,9 @@ xfs_showargs(
                 seq_printf(m, "," MNTOPT_LOGBSIZE "=%dk", mp->m_logbsize >> 10);
 
         if (mp->m_logname)
-                seq_printf(m, "," MNTOPT_LOGDEV "=%s", mp->m_logname);
+                seq_show_option(m, MNTOPT_LOGDEV, mp->m_logname);
         if (mp->m_rtname)
-                seq_printf(m, "," MNTOPT_RTDEV "=%s", mp->m_rtname);
+                seq_show_option(m, MNTOPT_RTDEV, mp->m_rtname);
 
         if (mp->m_dalign > 0)
                 seq_printf(m, "," MNTOPT_SUNIT "=%d",
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index 912a7c482649..d4c7271382cb 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -149,6 +149,41 @@ static inline struct user_namespace *seq_user_ns(struct seq_file *seq)
 #endif
 }
 
+/**
+ * seq_show_options - display mount options with appropriate escapes.
+ * @m: the seq_file handle
+ * @name: the mount option name
+ * @value: the mount option name's value, can be NULL
+ */
+static inline void seq_show_option(struct seq_file *m, const char *name,
+                                   const char *value)
+{
+        seq_putc(m, ',');
+        seq_escape(m, name, ",= \t\n\\");
+        if (value) {
+                seq_putc(m, '=');
+                seq_escape(m, value, ", \t\n\\");
+        }
+}
+
+/**
+ * seq_show_option_n - display mount options with appropriate escapes
+ *                     where @value must be a specific length.
+ * @m: the seq_file handle
+ * @name: the mount option name
+ * @value: the mount option name's value, cannot be NULL
+ * @length: the length of @value to display
+ *
+ * This is a macro since this uses "length" to define the size of the
+ * stack buffer.
+ */
+#define seq_show_option_n(m, name, value, length) {     \
+        char val_buf[length + 1];                       \
+        strncpy(val_buf, value, length);                \
+        val_buf[length] = '\0';                         \
+        seq_show_option(m, name, val_buf);              \
+}
+
 #define SEQ_START_TOKEN ((void *)1)
 /*
  * Helpers for iteration over list_head-s in seq_files
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index f3f5cd5e2c0d..a8538e443784 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1342,7 +1342,7 @@ static int cgroup_show_options(struct seq_file *seq,
         if (root != &cgrp_dfl_root)
                 for_each_subsys(ss, ssid)
                         if (root->subsys_mask & (1 << ssid))
-                                seq_printf(seq, ",%s", ss->legacy_name);
+                                seq_show_option(seq, ss->name, NULL);
         if (root->flags & CGRP_ROOT_NOPREFIX)
                 seq_puts(seq, ",noprefix");
         if (root->flags & CGRP_ROOT_XATTR)
@@ -1350,13 +1350,14 @@ static int cgroup_show_options(struct seq_file *seq,
 
         spin_lock(&release_agent_path_lock);
         if (strlen(root->release_agent_path))
-                seq_printf(seq, ",release_agent=%s", root->release_agent_path);
+                seq_show_option(seq, "release_agent",
+                                root->release_agent_path);
         spin_unlock(&release_agent_path_lock);
 
         if (test_bit(CGRP_CPUSET_CLONE_CHILDREN, &root->cgrp.flags))
                 seq_puts(seq, ",clone_children");
         if (strlen(root->name))
-                seq_printf(seq, ",name=%s", root->name);
+                seq_show_option(seq, "name", root->name);
         return 0;
 }
 
diff --git a/net/ceph/ceph_common.c b/net/ceph/ceph_common.c
index f30329f72641..69a4d30a9ccf 100644
--- a/net/ceph/ceph_common.c
+++ b/net/ceph/ceph_common.c
@@ -517,8 +517,11 @@ int ceph_print_client_options(struct seq_file *m, struct ceph_client *client)
         struct ceph_options *opt = client->options;
         size_t pos = m->count;
 
-        if (opt->name)
-                seq_printf(m, "name=%s,", opt->name);
+        if (opt->name) {
+                seq_puts(m, "name=");
+                seq_escape(m, opt->name, ", \t\n\\");
+                seq_putc(m, ',');
+        }
         if (opt->key)
                 seq_puts(m, "secret=<hidden>,");
 
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 564079c5c49d..cdf4c589a391 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1100,7 +1100,7 @@ static void selinux_write_opts(struct seq_file *m,
                 seq_puts(m, prefix);
                 if (has_comma)
                         seq_putc(m, '\"');
-                seq_puts(m, opts->mnt_opts[i]);
+                seq_escape(m, opts->mnt_opts[i], "\"\n\\");
                 if (has_comma)
                         seq_putc(m, '\"');
         }