From e3489f8974e178d723259a842a1e61708dd7dc1e Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 13 Dec 2018 00:24:36 -0500 Subject: selinux: kill selinux_sb_get_mnt_opts() it's much easier to just do the right thing in ->sb_show_options(), without bothering with allocating and populating arrays, etc. Reviewed-by: David Howells Signed-off-by: Al Viro --- security/selinux/hooks.c | 198 ++++++++++++----------------------------------- 1 file changed, 51 insertions(+), 147 deletions(-) (limited to 'security') diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index ce0511f024e0..11cf2feb27b3 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -591,105 +591,6 @@ out: return rc; } -/* - * This function should allow an FS to ask what it's mount security - * options were so it can use those later for submounts, displaying - * mount options, or whatever. - */ -static int selinux_get_mnt_opts(const struct super_block *sb, - struct security_mnt_opts *opts) -{ - int rc = 0, i; - struct superblock_security_struct *sbsec = sb->s_security; - char *context = NULL; - u32 len; - char tmp; - - security_init_mnt_opts(opts); - - if (!(sbsec->flags & SE_SBINITIALIZED)) - return -EINVAL; - - if (!selinux_state.initialized) - return -EINVAL; - - /* make sure we always check enough bits to cover the mask */ - BUILD_BUG_ON(SE_MNTMASK >= (1 << NUM_SEL_MNT_OPTS)); - - tmp = sbsec->flags & SE_MNTMASK; - /* count the number of mount options for this sb */ - for (i = 0; i < NUM_SEL_MNT_OPTS; i++) { - if (tmp & 0x01) - opts->num_mnt_opts++; - tmp >>= 1; - } - /* Check if the Label support flag is set */ - if (sbsec->flags & SBLABEL_MNT) - opts->num_mnt_opts++; - - opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC); - if (!opts->mnt_opts) { - rc = -ENOMEM; - goto out_free; - } - - opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC); - if (!opts->mnt_opts_flags) { - rc = -ENOMEM; - goto out_free; - } - - i = 0; - if (sbsec->flags & FSCONTEXT_MNT) { - rc = security_sid_to_context(&selinux_state, sbsec->sid, - &context, &len); - if (rc) - goto out_free; - opts->mnt_opts[i] = context; - opts->mnt_opts_flags[i++] = FSCONTEXT_MNT; - } - if (sbsec->flags & CONTEXT_MNT) { - rc = security_sid_to_context(&selinux_state, - sbsec->mntpoint_sid, - &context, &len); - if (rc) - goto out_free; - opts->mnt_opts[i] = context; - opts->mnt_opts_flags[i++] = CONTEXT_MNT; - } - if (sbsec->flags & DEFCONTEXT_MNT) { - rc = security_sid_to_context(&selinux_state, sbsec->def_sid, - &context, &len); - if (rc) - goto out_free; - opts->mnt_opts[i] = context; - opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT; - } - if (sbsec->flags & ROOTCONTEXT_MNT) { - struct dentry *root = sbsec->sb->s_root; - struct inode_security_struct *isec = backing_inode_security(root); - - rc = security_sid_to_context(&selinux_state, isec->sid, - &context, &len); - if (rc) - goto out_free; - opts->mnt_opts[i] = context; - opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT; - } - if (sbsec->flags & SBLABEL_MNT) { - opts->mnt_opts[i] = NULL; - opts->mnt_opts_flags[i++] = SBLABEL_MNT; - } - - BUG_ON(i != opts->num_mnt_opts); - - return 0; - -out_free: - security_free_mnt_opts(opts); - return rc; -} - static int bad_option(struct superblock_security_struct *sbsec, char flag, u32 old_sid, u32 new_sid) { @@ -1201,70 +1102,73 @@ out_err: return rc; } -static void selinux_write_opts(struct seq_file *m, - struct security_mnt_opts *opts) +static int show_sid(struct seq_file *m, u32 sid) { - int i; - char *prefix; - - for (i = 0; i < opts->num_mnt_opts; i++) { - char *has_comma; + char *context = NULL; + u32 len; + int rc; - if (opts->mnt_opts[i]) - has_comma = strchr(opts->mnt_opts[i], ','); - else - has_comma = NULL; + rc = security_sid_to_context(&selinux_state, sid, + &context, &len); + if (!rc) { + bool has_comma = context && strchr(context, ','); - 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; - case SBLABEL_MNT: - seq_putc(m, ','); - seq_puts(m, LABELSUPP_STR); - continue; - default: - BUG(); - return; - }; - /* we need a comma before each option */ - seq_putc(m, ','); - seq_puts(m, prefix); if (has_comma) seq_putc(m, '\"'); - seq_escape(m, opts->mnt_opts[i], "\"\n\\"); + seq_escape(m, context, "\"\n\\"); if (has_comma) seq_putc(m, '\"'); } + kfree(context); + return rc; } static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb) { - struct security_mnt_opts opts; + struct superblock_security_struct *sbsec = sb->s_security; int rc; - rc = selinux_get_mnt_opts(sb, &opts); - if (rc) { - /* before policy load we may get EINVAL, don't show anything */ - if (rc == -EINVAL) - rc = 0; - return rc; - } - - selinux_write_opts(m, &opts); + if (!(sbsec->flags & SE_SBINITIALIZED)) + return 0; - security_free_mnt_opts(&opts); + if (!selinux_state.initialized) + return 0; - return rc; + if (sbsec->flags & FSCONTEXT_MNT) { + seq_putc(m, ','); + seq_puts(m, FSCONTEXT_STR); + rc = show_sid(m, sbsec->sid); + if (rc) + return rc; + } + if (sbsec->flags & CONTEXT_MNT) { + seq_putc(m, ','); + seq_puts(m, CONTEXT_STR); + rc = show_sid(m, sbsec->mntpoint_sid); + if (rc) + return rc; + } + if (sbsec->flags & DEFCONTEXT_MNT) { + seq_putc(m, ','); + seq_puts(m, DEFCONTEXT_STR); + rc = show_sid(m, sbsec->def_sid); + if (rc) + return rc; + } + if (sbsec->flags & ROOTCONTEXT_MNT) { + struct dentry *root = sbsec->sb->s_root; + struct inode_security_struct *isec = backing_inode_security(root); + seq_putc(m, ','); + seq_puts(m, ROOTCONTEXT_STR); + rc = show_sid(m, isec->sid); + if (rc) + return rc; + } + if (sbsec->flags & SBLABEL_MNT) { + seq_putc(m, ','); + seq_puts(m, LABELSUPP_STR); + } + return 0; } static inline u16 inode_mode_to_security_class(umode_t mode) -- cgit v1.2.3