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authorLinus Torvalds <torvalds@linux-foundation.org>2019-01-05 13:25:58 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-01-05 13:25:58 -0800
commit505b050fdf42097883b2d37b8e796e1f11dbef50 (patch)
tree21f5b43505a5771d13533ac675c785a9bf480fdc /security/smack
parent9b286efeb5eb5aaa2712873fc1f928b2f879dbde (diff)
parent718c43038f287e843c2f63d946977de90014cb11 (diff)
downloadlinux-505b050fdf42097883b2d37b8e796e1f11dbef50.tar.gz
Merge branch 'mount.part1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs mount API prep from Al Viro: "Mount API prereqs. Mostly that's LSM mount options cleanups. There are several minor fixes in there, but nothing earth-shattering (leaks on failure exits, mostly)" * 'mount.part1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (27 commits) mount_fs: suppress MAC on MS_SUBMOUNT as well as MS_KERNMOUNT smack: rewrite smack_sb_eat_lsm_opts() smack: get rid of match_token() smack: take the guts of smack_parse_opts_str() into a new helper LSM: new method: ->sb_add_mnt_opt() selinux: rewrite selinux_sb_eat_lsm_opts() selinux: regularize Opt_... names a bit selinux: switch away from match_token() selinux: new helper - selinux_add_opt() LSM: bury struct security_mnt_opts smack: switch to private smack_mnt_opts selinux: switch to private struct selinux_mnt_opts LSM: hide struct security_mnt_opts from any generic code selinux: kill selinux_sb_get_mnt_opts() LSM: turn sb_eat_lsm_opts() into a method nfs_remount(): don't leak, don't ignore LSM options quietly btrfs: sanitize security_mnt_opts use selinux; don't open-code a loop in sb_finish_set_opts() LSM: split ->sb_set_mnt_opts() out of ->sb_kern_mount() new helper: security_sb_eat_lsm_opts() ...
Diffstat (limited to 'security/smack')
-rw-r--r--security/smack/smack_lsm.c359
1 files changed, 137 insertions, 222 deletions
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index cd720c06b78c..430d4f35e55c 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -59,14 +59,31 @@ static LIST_HEAD(smk_ipv6_port_list);
static struct kmem_cache *smack_inode_cache;
int smack_enabled;
-static const match_table_t smk_mount_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},
+#define A(s) {"smack"#s, sizeof("smack"#s) - 1, Opt_##s}
+static struct {
+ const char *name;
+ int len;
+ int opt;
+} smk_mount_opts[] = {
+ A(fsdefault), A(fsfloor), A(fshat), A(fsroot), A(fstransmute)
};
+#undef A
+
+static int match_opt_prefix(char *s, int l, char **arg)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(smk_mount_opts); i++) {
+ size_t len = smk_mount_opts[i].len;
+ if (len > l || memcmp(s, smk_mount_opts[i].name, len))
+ continue;
+ if (len == l || s[len] != '=')
+ continue;
+ *arg = s + len + 1;
+ return smk_mount_opts[i].opt;
+ }
+ return Opt_error;
+}
#ifdef CONFIG_SECURITY_SMACK_BRINGUP
static char *smk_bu_mess[] = {
@@ -567,175 +584,110 @@ static void smack_sb_free_security(struct super_block *sb)
sb->s_security = NULL;
}
-/**
- * smack_sb_copy_data - copy mount options data for processing
- * @orig: where to start
- * @smackopts: mount options string
- *
- * Returns 0 on success or -ENOMEM on error.
- *
- * Copy the Smack specific mount options out of the mount
- * options list.
- */
-static int smack_sb_copy_data(char *orig, char *smackopts)
-{
- char *cp, *commap, *otheropts, *dp;
-
- otheropts = (char *)get_zeroed_page(GFP_KERNEL);
- if (otheropts == NULL)
- return -ENOMEM;
+struct smack_mnt_opts {
+ const char *fsdefault, *fsfloor, *fshat, *fsroot, *fstransmute;
+};
- for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) {
- if (strstr(cp, SMK_FSDEFAULT) == cp)
- dp = smackopts;
- else if (strstr(cp, SMK_FSFLOOR) == cp)
- dp = smackopts;
- else if (strstr(cp, SMK_FSHAT) == cp)
- dp = smackopts;
- else if (strstr(cp, SMK_FSROOT) == cp)
- dp = smackopts;
- else if (strstr(cp, SMK_FSTRANS) == cp)
- dp = smackopts;
- else
- dp = otheropts;
+static void smack_free_mnt_opts(void *mnt_opts)
+{
+ struct smack_mnt_opts *opts = mnt_opts;
+ kfree(opts->fsdefault);
+ kfree(opts->fsfloor);
+ kfree(opts->fshat);
+ kfree(opts->fsroot);
+ kfree(opts->fstransmute);
+ kfree(opts);
+}
- commap = strchr(cp, ',');
- if (commap != NULL)
- *commap = '\0';
+static int smack_add_opt(int token, const char *s, void **mnt_opts)
+{
+ struct smack_mnt_opts *opts = *mnt_opts;
- if (*dp != '\0')
- strcat(dp, ",");
- strcat(dp, cp);
+ if (!opts) {
+ opts = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL);
+ if (!opts)
+ return -ENOMEM;
+ *mnt_opts = opts;
}
+ if (!s)
+ return -ENOMEM;
- strcpy(orig, otheropts);
- free_page((unsigned long)otheropts);
-
+ switch (token) {
+ case Opt_fsdefault:
+ if (opts->fsdefault)
+ goto out_opt_err;
+ opts->fsdefault = s;
+ break;
+ case Opt_fsfloor:
+ if (opts->fsfloor)
+ goto out_opt_err;
+ opts->fsfloor = s;
+ break;
+ case Opt_fshat:
+ if (opts->fshat)
+ goto out_opt_err;
+ opts->fshat = s;
+ break;
+ case Opt_fsroot:
+ if (opts->fsroot)
+ goto out_opt_err;
+ opts->fsroot = s;
+ break;
+ case Opt_fstransmute:
+ if (opts->fstransmute)
+ goto out_opt_err;
+ opts->fstransmute = s;
+ break;
+ }
return 0;
+
+out_opt_err:
+ pr_warn("Smack: duplicate mount options\n");
+ return -EINVAL;
}
-/**
- * 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)
+static int smack_sb_eat_lsm_opts(char *options, void **mnt_opts)
{
- char *p;
- char *fsdefault = NULL;
- char *fsfloor = NULL;
- char *fshat = NULL;
- char *fsroot = NULL;
- char *fstransmute = NULL;
- int rc = -ENOMEM;
- int num_mnt_opts = 0;
- int token;
-
- opts->num_mnt_opts = 0;
-
- if (!options)
- return 0;
-
- while ((p = strsep(&options, ",")) != NULL) {
- substring_t args[MAX_OPT_ARGS];
+ char *from = options, *to = options;
+ bool first = true;
- if (!*p)
- continue;
-
- token = match_token(p, smk_mount_tokens, args);
+ while (1) {
+ char *next = strchr(from, ',');
+ int token, len, rc;
+ char *arg = NULL;
- 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;
+ if (next)
+ len = next - from;
+ else
+ len = strlen(from);
+
+ token = match_opt_prefix(from, len, &arg);
+ if (token != Opt_error) {
+ arg = kmemdup_nul(arg, from + len - arg, GFP_KERNEL);
+ rc = smack_add_opt(token, arg, mnt_opts);
+ if (unlikely(rc)) {
+ kfree(arg);
+ if (*mnt_opts)
+ smack_free_mnt_opts(*mnt_opts);
+ *mnt_opts = NULL;
+ return rc;
+ }
+ } else {
+ if (!first) { // copy with preceding comma
+ from--;
+ len++;
+ }
+ if (to != from)
+ memmove(to, from, len);
+ to += len;
+ first = false;
}
+ if (!from[len])
+ break;
+ from += len + 1;
}
-
- opts->mnt_opts = kcalloc(NUM_SMK_MNT_OPTS, sizeof(char *), GFP_KERNEL);
- if (!opts->mnt_opts)
- goto out_err;
-
- opts->mnt_opts_flags = kcalloc(NUM_SMK_MNT_OPTS, sizeof(int),
- GFP_KERNEL);
- if (!opts->mnt_opts_flags)
- 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;
+ *to = '\0';
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;
}
/**
@@ -751,7 +703,7 @@ out_err:
* labels.
*/
static int smack_set_mnt_opts(struct super_block *sb,
- struct security_mnt_opts *opts,
+ void *mnt_opts,
unsigned long kern_flags,
unsigned long *set_kern_flags)
{
@@ -760,9 +712,8 @@ static int smack_set_mnt_opts(struct super_block *sb,
struct superblock_smack *sp = sb->s_security;
struct inode_smack *isp;
struct smack_known *skp;
- int i;
- int num_opts = opts->num_mnt_opts;
- int transmute = 0;
+ struct smack_mnt_opts *opts = mnt_opts;
+ bool transmute = false;
if (sp->smk_flags & SMK_SB_INITIALIZED)
return 0;
@@ -771,7 +722,7 @@ static int smack_set_mnt_opts(struct super_block *sb,
/*
* Unprivileged mounts don't get to specify Smack values.
*/
- if (num_opts)
+ if (opts)
return -EPERM;
/*
* Unprivileged mounts get root and default from the caller.
@@ -787,48 +738,44 @@ static int smack_set_mnt_opts(struct super_block *sb,
if (sb->s_user_ns != &init_user_ns &&
sb->s_magic != SYSFS_MAGIC && sb->s_magic != TMPFS_MAGIC &&
sb->s_magic != RAMFS_MAGIC) {
- transmute = 1;
+ transmute = true;
sp->smk_flags |= SMK_SB_UNTRUSTED;
}
}
sp->smk_flags |= SMK_SB_INITIALIZED;
- 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 (opts) {
+ if (opts->fsdefault) {
+ skp = smk_import_entry(opts->fsdefault, 0);
if (IS_ERR(skp))
return PTR_ERR(skp);
sp->smk_default = skp;
- break;
- case FSFLOOR_MNT:
- skp = smk_import_entry(opts->mnt_opts[i], 0);
+ }
+ if (opts->fsfloor) {
+ skp = smk_import_entry(opts->fsfloor, 0);
if (IS_ERR(skp))
return PTR_ERR(skp);
sp->smk_floor = skp;
- break;
- case FSHAT_MNT:
- skp = smk_import_entry(opts->mnt_opts[i], 0);
+ }
+ if (opts->fshat) {
+ skp = smk_import_entry(opts->fshat, 0);
if (IS_ERR(skp))
return PTR_ERR(skp);
sp->smk_hat = skp;
- break;
- case FSROOT_MNT:
- skp = smk_import_entry(opts->mnt_opts[i], 0);
+ }
+ if (opts->fsroot) {
+ skp = smk_import_entry(opts->fsroot, 0);
if (IS_ERR(skp))
return PTR_ERR(skp);
sp->smk_root = skp;
- break;
- case FSTRANS_MNT:
- skp = smk_import_entry(opts->mnt_opts[i], 0);
+ }
+ if (opts->fstransmute) {
+ skp = smk_import_entry(opts->fstransmute, 0);
if (IS_ERR(skp))
return PTR_ERR(skp);
sp->smk_root = skp;
- transmute = 1;
- break;
- default:
- break;
+ transmute = true;
}
}
@@ -851,37 +798,6 @@ static int smack_set_mnt_opts(struct super_block *sb,
}
/**
- * 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
*
@@ -4673,11 +4589,10 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(sb_alloc_security, smack_sb_alloc_security),
LSM_HOOK_INIT(sb_free_security, smack_sb_free_security),
- LSM_HOOK_INIT(sb_copy_data, smack_sb_copy_data),
- LSM_HOOK_INIT(sb_kern_mount, smack_sb_kern_mount),
+ LSM_HOOK_INIT(sb_free_mnt_opts, smack_free_mnt_opts),
+ LSM_HOOK_INIT(sb_eat_lsm_opts, smack_sb_eat_lsm_opts),
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),