From 2069f457848f846cb31149c9aa29b330a6b66d1b Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Fri, 4 Jul 2008 09:47:13 +1000 Subject: [PATCH] LSM/SELinux: show LSM mount options in /proc/mounts This patch causes SELinux mount options to show up in /proc/mounts. As with other code in the area seq_put errors are ignored. Other LSM's will not have their mount options displayed until they fill in their own security_sb_show_options() function. Signed-off-by: Eric Paris Signed-off-by: Miklos Szeredi Signed-off-by: James Morris --- fs/namespace.c | 14 +++++++--- include/linux/security.h | 9 +++++++ security/dummy.c | 6 +++++ security/security.c | 5 ++++ security/selinux/hooks.c | 55 +++++++++++++++++++++++++++++++++++++++- 5 files changed, 85 insertions(+), 4 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index 4fc302c2a0..4f6f7635b5 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -750,7 +750,7 @@ struct proc_fs_info { const char *str; }; -static void show_sb_opts(struct seq_file *m, struct super_block *sb) +static int show_sb_opts(struct seq_file *m, struct super_block *sb) { static const struct proc_fs_info fs_info[] = { { MS_SYNCHRONOUS, ",sync" }, @@ -764,6 +764,8 @@ static void show_sb_opts(struct seq_file *m, struct super_block *sb) if (sb->s_flags & fs_infop->flag) seq_puts(m, fs_infop->str); } + + return security_sb_show_options(m, sb); } static void show_mnt_opts(struct seq_file *m, struct vfsmount *mnt) @@ -806,11 +808,14 @@ static int show_vfsmnt(struct seq_file *m, void *v) seq_putc(m, ' '); show_type(m, mnt->mnt_sb); seq_puts(m, __mnt_is_readonly(mnt) ? " ro" : " rw"); - show_sb_opts(m, mnt->mnt_sb); + err = show_sb_opts(m, mnt->mnt_sb); + if (err) + goto out; show_mnt_opts(m, mnt); if (mnt->mnt_sb->s_op->show_options) err = mnt->mnt_sb->s_op->show_options(m, mnt); seq_puts(m, " 0 0\n"); +out: return err; } @@ -865,10 +870,13 @@ static int show_mountinfo(struct seq_file *m, void *v) seq_putc(m, ' '); mangle(m, mnt->mnt_devname ? mnt->mnt_devname : "none"); seq_puts(m, sb->s_flags & MS_RDONLY ? " ro" : " rw"); - show_sb_opts(m, sb); + err = show_sb_opts(m, sb); + if (err) + goto out; if (sb->s_op->show_options) err = sb->s_op->show_options(m, mnt); seq_putc(m, '\n'); +out: return err; } diff --git a/include/linux/security.h b/include/linux/security.h index 62bd80cb7f..c8ad8ec684 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -80,6 +80,7 @@ struct xfrm_selector; struct xfrm_policy; struct xfrm_state; struct xfrm_user_sec_ctx; +struct seq_file; extern int cap_netlink_send(struct sock *sk, struct sk_buff *skb); extern int cap_netlink_recv(struct sk_buff *skb, int cap); @@ -1331,6 +1332,7 @@ struct security_operations { void (*sb_free_security) (struct super_block *sb); int (*sb_copy_data) (char *orig, char *copy); int (*sb_kern_mount) (struct super_block *sb, void *data); + int (*sb_show_options) (struct seq_file *m, struct super_block *sb); int (*sb_statfs) (struct dentry *dentry); int (*sb_mount) (char *dev_name, struct path *path, char *type, unsigned long flags, void *data); @@ -1610,6 +1612,7 @@ int security_sb_alloc(struct super_block *sb); void security_sb_free(struct super_block *sb); int security_sb_copy_data(char *orig, char *copy); int security_sb_kern_mount(struct super_block *sb, void *data); +int security_sb_show_options(struct seq_file *m, struct super_block *sb); int security_sb_statfs(struct dentry *dentry); int security_sb_mount(char *dev_name, struct path *path, char *type, unsigned long flags, void *data); @@ -1887,6 +1890,12 @@ static inline int security_sb_kern_mount(struct super_block *sb, void *data) return 0; } +static inline int security_sb_show_options(struct seq_file *m, + struct super_block *sb) +{ + return 0; +} + static inline int security_sb_statfs(struct dentry *dentry) { return 0; diff --git a/security/dummy.c b/security/dummy.c index 1db712d99d..c155f08e9d 100644 --- a/security/dummy.c +++ b/security/dummy.c @@ -194,6 +194,11 @@ static int dummy_sb_kern_mount (struct super_block *sb, void *data) return 0; } +static int dummy_sb_show_options(struct seq_file *m, struct super_block *sb) +{ + return 0; +} + static int dummy_sb_statfs (struct dentry *dentry) { return 0; @@ -1088,6 +1093,7 @@ void security_fixup_ops (struct security_operations *ops) set_to_dummy_if_null(ops, sb_free_security); set_to_dummy_if_null(ops, sb_copy_data); set_to_dummy_if_null(ops, sb_kern_mount); + set_to_dummy_if_null(ops, sb_show_options); set_to_dummy_if_null(ops, sb_statfs); set_to_dummy_if_null(ops, sb_mount); set_to_dummy_if_null(ops, sb_check_sb); diff --git a/security/security.c b/security/security.c index 2c0a5876b9..de74fdccde 100644 --- a/security/security.c +++ b/security/security.c @@ -292,6 +292,11 @@ int security_sb_kern_mount(struct super_block *sb, void *data) return security_ops->sb_kern_mount(sb, data); } +int security_sb_show_options(struct seq_file *m, struct super_block *sb) +{ + return security_ops->sb_show_options(m, sb); +} + int security_sb_statfs(struct dentry *dentry) { return security_ops->sb_statfs(dentry); diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 85f74f6657..33dee83fdd 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -9,7 +9,8 @@ * James Morris * * Copyright (C) 2001,2002 Networks Associates Technology, Inc. - * Copyright (C) 2003 Red Hat, Inc., James Morris + * Copyright (C) 2003-2008 Red Hat, Inc., James Morris + * Eric Paris * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc. * * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P. @@ -970,6 +971,57 @@ out_err: return rc; } +void selinux_write_opts(struct seq_file *m, struct security_mnt_opts *opts) +{ + int i; + char *prefix; + + for (i = 0; i < opts->num_mnt_opts; i++) { + char *has_comma = strchr(opts->mnt_opts[i], ','); + + switch (opts->mnt_opts_flags[i]) { + case CONTEXT_MNT: + prefix = CONTEXT_STR; + break; + case FSCONTEXT_MNT: + prefix = FSCONTEXT_STR; + break; + case ROOTCONTEXT_MNT: + prefix = ROOTCONTEXT_STR; + break; + case DEFCONTEXT_MNT: + prefix = DEFCONTEXT_STR; + break; + default: + BUG(); + }; + /* we need a comma before each option */ + seq_putc(m, ','); + seq_puts(m, prefix); + if (has_comma) + seq_putc(m, '\"'); + seq_puts(m, opts->mnt_opts[i]); + if (has_comma) + seq_putc(m, '\"'); + } +} + +static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb) +{ + struct security_mnt_opts opts; + int rc; + + rc = selinux_get_mnt_opts(sb, &opts); + if (rc) + return rc; + + selinux_write_opts(m, &opts); + + security_free_mnt_opts(&opts); + + return rc; +} + static inline u16 inode_mode_to_security_class(umode_t mode) { switch (mode & S_IFMT) { @@ -5365,6 +5417,7 @@ static struct security_operations selinux_ops = { .sb_free_security = selinux_sb_free_security, .sb_copy_data = selinux_sb_copy_data, .sb_kern_mount = selinux_sb_kern_mount, + .sb_show_options = selinux_sb_show_options, .sb_statfs = selinux_sb_statfs, .sb_mount = selinux_mount, .sb_umount = selinux_umount, -- 2.39.5