diff options
Diffstat (limited to 'security/smack/smack_lsm.c')
| -rw-r--r-- | security/smack/smack_lsm.c | 241 |
1 files changed, 201 insertions, 40 deletions
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index a143328f75eb..d962f887d3f4 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -41,6 +41,7 @@ #include <linux/msg.h> #include <linux/shm.h> #include <linux/binfmts.h> +#include <linux/parser.h> #include "smack.h" #define TRANS_TRUE "TRUE" @@ -64,6 +65,15 @@ static char *smk_bu_mess[] = { "Unconfined Object", /* SMACK_UNCONFINED_OBJECT */ }; +static const match_table_t tokens = { + {Opt_fsdefault, SMK_FSDEFAULT "%s"}, + {Opt_fsfloor, SMK_FSFLOOR "%s"}, + {Opt_fshat, SMK_FSHAT "%s"}, + {Opt_fsroot, SMK_FSROOT "%s"}, + {Opt_fstransmute, SMK_FSTRANS "%s"}, + {Opt_error, NULL}, +}; + static void smk_bu_mode(int mode, char *s) { int i = 0; @@ -577,76 +587,193 @@ static int smack_sb_copy_data(char *orig, char *smackopts) } /** - * smack_sb_kern_mount - Smack specific mount processing + * smack_parse_opts_str - parse Smack specific mount options + * @options: mount options string + * @opts: where to store converted mount opts + * + * Returns 0 on success or -ENOMEM on error. + * + * converts Smack specific mount options to generic security option format + */ +static int smack_parse_opts_str(char *options, + struct security_mnt_opts *opts) +{ + char *p; + char *fsdefault = NULL, *fsfloor = NULL; + char *fshat = NULL, *fsroot = NULL, *fstransmute = NULL; + int rc = -ENOMEM, num_mnt_opts = 0; + + opts->num_mnt_opts = 0; + + if (!options) + return 0; + + while ((p = strsep(&options, ",")) != NULL) { + int token; + substring_t args[MAX_OPT_ARGS]; + + if (!*p) + continue; + + token = match_token(p, tokens, args); + + switch (token) { + case Opt_fsdefault: + if (fsdefault) + goto out_opt_err; + fsdefault = match_strdup(&args[0]); + if (!fsdefault) + goto out_err; + break; + case Opt_fsfloor: + if (fsfloor) + goto out_opt_err; + fsfloor = match_strdup(&args[0]); + if (!fsfloor) + goto out_err; + break; + case Opt_fshat: + if (fshat) + goto out_opt_err; + fshat = match_strdup(&args[0]); + if (!fshat) + goto out_err; + break; + case Opt_fsroot: + if (fsroot) + goto out_opt_err; + fsroot = match_strdup(&args[0]); + if (!fsroot) + goto out_err; + break; + case Opt_fstransmute: + if (fstransmute) + goto out_opt_err; + fstransmute = match_strdup(&args[0]); + if (!fstransmute) + goto out_err; + break; + default: + rc = -EINVAL; + pr_warn("Smack: unknown mount option\n"); + goto out_err; + } + } + + opts->mnt_opts = kcalloc(NUM_SMK_MNT_OPTS, sizeof(char *), GFP_ATOMIC); + if (!opts->mnt_opts) + goto out_err; + + opts->mnt_opts_flags = kcalloc(NUM_SMK_MNT_OPTS, sizeof(int), + GFP_ATOMIC); + if (!opts->mnt_opts_flags) { + kfree(opts->mnt_opts); + goto out_err; + } + + if (fsdefault) { + opts->mnt_opts[num_mnt_opts] = fsdefault; + opts->mnt_opts_flags[num_mnt_opts++] = FSDEFAULT_MNT; + } + if (fsfloor) { + opts->mnt_opts[num_mnt_opts] = fsfloor; + opts->mnt_opts_flags[num_mnt_opts++] = FSFLOOR_MNT; + } + if (fshat) { + opts->mnt_opts[num_mnt_opts] = fshat; + opts->mnt_opts_flags[num_mnt_opts++] = FSHAT_MNT; + } + if (fsroot) { + opts->mnt_opts[num_mnt_opts] = fsroot; + opts->mnt_opts_flags[num_mnt_opts++] = FSROOT_MNT; + } + if (fstransmute) { + opts->mnt_opts[num_mnt_opts] = fstransmute; + opts->mnt_opts_flags[num_mnt_opts++] = FSTRANS_MNT; + } + + opts->num_mnt_opts = num_mnt_opts; + return 0; + +out_opt_err: + rc = -EINVAL; + pr_warn("Smack: duplicate mount options\n"); + +out_err: + kfree(fsdefault); + kfree(fsfloor); + kfree(fshat); + kfree(fsroot); + kfree(fstransmute); + return rc; +} + +/** + * smack_set_mnt_opts - set Smack specific mount options * @sb: the file system superblock - * @flags: the mount flags - * @data: the smack mount options + * @opts: Smack mount options + * @kern_flags: mount option from kernel space or user space + * @set_kern_flags: where to store converted mount opts * * Returns 0 on success, an error code on failure + * + * Allow filesystems with binary mount data to explicitly set Smack mount + * labels. */ -static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data) +static int smack_set_mnt_opts(struct super_block *sb, + struct security_mnt_opts *opts, + unsigned long kern_flags, + unsigned long *set_kern_flags) { struct dentry *root = sb->s_root; struct inode *inode = d_backing_inode(root); struct superblock_smack *sp = sb->s_security; struct inode_smack *isp; struct smack_known *skp; - char *op; - char *commap; + int i; + int num_opts = opts->num_mnt_opts; int transmute = 0; - int specified = 0; if (sp->smk_initialized) return 0; sp->smk_initialized = 1; - for (op = data; op != NULL; op = commap) { - commap = strchr(op, ','); - if (commap != NULL) - *commap++ = '\0'; - - if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) { - op += strlen(SMK_FSHAT); - skp = smk_import_entry(op, 0); + for (i = 0; i < num_opts; i++) { + switch (opts->mnt_opts_flags[i]) { + case FSDEFAULT_MNT: + skp = smk_import_entry(opts->mnt_opts[i], 0); if (IS_ERR(skp)) return PTR_ERR(skp); - sp->smk_hat = skp; - specified = 1; - - } else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) { - op += strlen(SMK_FSFLOOR); - skp = smk_import_entry(op, 0); + sp->smk_default = skp; + break; + case FSFLOOR_MNT: + skp = smk_import_entry(opts->mnt_opts[i], 0); if (IS_ERR(skp)) return PTR_ERR(skp); sp->smk_floor = skp; - specified = 1; - - } else if (strncmp(op, SMK_FSDEFAULT, - strlen(SMK_FSDEFAULT)) == 0) { - op += strlen(SMK_FSDEFAULT); - skp = smk_import_entry(op, 0); + break; + case FSHAT_MNT: + skp = smk_import_entry(opts->mnt_opts[i], 0); if (IS_ERR(skp)) return PTR_ERR(skp); - sp->smk_default = skp; - specified = 1; - - } else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) { - op += strlen(SMK_FSROOT); - skp = smk_import_entry(op, 0); + sp->smk_hat = skp; + break; + case FSROOT_MNT: + skp = smk_import_entry(opts->mnt_opts[i], 0); if (IS_ERR(skp)) return PTR_ERR(skp); sp->smk_root = skp; - specified = 1; - - } else if (strncmp(op, SMK_FSTRANS, strlen(SMK_FSTRANS)) == 0) { - op += strlen(SMK_FSTRANS); - skp = smk_import_entry(op, 0); + break; + case FSTRANS_MNT: + skp = smk_import_entry(opts->mnt_opts[i], 0); if (IS_ERR(skp)) return PTR_ERR(skp); sp->smk_root = skp; transmute = 1; - specified = 1; + break; + default: + break; } } @@ -654,7 +781,7 @@ static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data) /* * Unprivileged mounts don't get to specify Smack values. */ - if (specified) + if (num_opts) return -EPERM; /* * Unprivileged mounts get root and default from the caller. @@ -663,6 +790,7 @@ static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data) sp->smk_root = skp; sp->smk_default = skp; } + /* * Initialize the root inode. */ @@ -682,6 +810,37 @@ static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data) } /** + * smack_sb_kern_mount - Smack specific mount processing + * @sb: the file system superblock + * @flags: the mount flags + * @data: the smack mount options + * + * Returns 0 on success, an error code on failure + */ +static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data) +{ + int rc = 0; + char *options = data; + struct security_mnt_opts opts; + + security_init_mnt_opts(&opts); + + if (!options) + goto out; + + rc = smack_parse_opts_str(options, &opts); + if (rc) + goto out_err; + +out: + rc = smack_set_mnt_opts(sb, &opts, 0, NULL); + +out_err: + security_free_mnt_opts(&opts); + return rc; +} + +/** * smack_sb_statfs - Smack check on statfs * @dentry: identifies the file system in question * @@ -4264,6 +4423,8 @@ struct security_hook_list smack_hooks[] = { LSM_HOOK_INIT(sb_copy_data, smack_sb_copy_data), LSM_HOOK_INIT(sb_kern_mount, smack_sb_kern_mount), LSM_HOOK_INIT(sb_statfs, smack_sb_statfs), + LSM_HOOK_INIT(sb_set_mnt_opts, smack_set_mnt_opts), + LSM_HOOK_INIT(sb_parse_opts_str, smack_parse_opts_str), LSM_HOOK_INIT(bprm_set_creds, smack_bprm_set_creds), LSM_HOOK_INIT(bprm_committing_creds, smack_bprm_committing_creds), |