From 442155c1bd84f82bff2d05d0ec4d0090df17ecfa Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 1 Nov 2018 23:07:24 +0000 Subject: selinux: Implement the new mount API LSM hooks Implement the new mount API LSM hooks for SELinux. At some point the old hooks will need to be removed. Signed-off-by: David Howells cc: Paul Moore cc: Stephen Smalley cc: selinux@tycho.nsa.gov cc: linux-security-module@vger.kernel.org Signed-off-by: Al Viro --- security/selinux/hooks.c | 49 +++++++++++++++++++++++++++++++++---- security/selinux/include/security.h | 10 ++++---- 2 files changed, 49 insertions(+), 10 deletions(-) (limited to 'security/selinux') diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index f0e36c3492ba..f99381e97d73 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -48,6 +48,8 @@ #include #include #include +#include +#include #include #include #include @@ -454,11 +456,11 @@ static inline int inode_doinit(struct inode *inode) enum { Opt_error = -1, - Opt_context = 1, + Opt_context = 0, + Opt_defcontext = 1, Opt_fscontext = 2, - Opt_defcontext = 3, - Opt_rootcontext = 4, - Opt_seclabel = 5, + Opt_rootcontext = 3, + Opt_seclabel = 4, }; #define A(s, has_arg) {#s, sizeof(#s) - 1, Opt_##s, has_arg} @@ -1089,6 +1091,7 @@ static int show_sid(struct seq_file *m, u32 sid) if (!rc) { bool has_comma = context && strchr(context, ','); + seq_putc(m, '='); if (has_comma) seq_putc(m, '\"'); seq_escape(m, context, "\"\n\\"); @@ -1142,7 +1145,7 @@ static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb) } if (sbsec->flags & SBLABEL_MNT) { seq_putc(m, ','); - seq_puts(m, LABELSUPP_STR); + seq_puts(m, SECLABEL_STR); } return 0; } @@ -2761,6 +2764,38 @@ static int selinux_umount(struct vfsmount *mnt, int flags) FILESYSTEM__UNMOUNT, NULL); } +static const struct fs_parameter_spec selinux_param_specs[] = { + fsparam_string(CONTEXT_STR, Opt_context), + fsparam_string(DEFCONTEXT_STR, Opt_defcontext), + fsparam_string(FSCONTEXT_STR, Opt_fscontext), + fsparam_string(ROOTCONTEXT_STR, Opt_rootcontext), + fsparam_flag (SECLABEL_STR, Opt_seclabel), + {} +}; + +static const struct fs_parameter_description selinux_fs_parameters = { + .name = "SELinux", + .specs = selinux_param_specs, +}; + +static int selinux_fs_context_parse_param(struct fs_context *fc, + struct fs_parameter *param) +{ + struct fs_parse_result result; + int opt, rc; + + opt = fs_parse(fc, &selinux_fs_parameters, param, &result); + if (opt < 0) + return opt; + + rc = selinux_add_opt(opt, param->string, &fc->security); + if (!rc) { + param->string = NULL; + rc = 1; + } + return rc; +} + /* inode security operations */ static int selinux_inode_alloc_security(struct inode *inode) @@ -6710,6 +6745,8 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(bprm_committing_creds, selinux_bprm_committing_creds), LSM_HOOK_INIT(bprm_committed_creds, selinux_bprm_committed_creds), + LSM_HOOK_INIT(fs_context_parse_param, selinux_fs_context_parse_param), + LSM_HOOK_INIT(sb_alloc_security, selinux_sb_alloc_security), LSM_HOOK_INIT(sb_free_security, selinux_sb_free_security), LSM_HOOK_INIT(sb_eat_lsm_opts, selinux_sb_eat_lsm_opts), @@ -6978,6 +7015,8 @@ static __init int selinux_init(void) else pr_debug("SELinux: Starting in permissive mode\n"); + fs_validate_description(&selinux_fs_parameters); + return 0; } diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h index ba8eedf42b90..529d8941c9c5 100644 --- a/security/selinux/include/security.h +++ b/security/selinux/include/security.h @@ -59,11 +59,11 @@ #define SE_SBPROC 0x0200 #define SE_SBGENFS 0x0400 -#define CONTEXT_STR "context=" -#define FSCONTEXT_STR "fscontext=" -#define ROOTCONTEXT_STR "rootcontext=" -#define DEFCONTEXT_STR "defcontext=" -#define LABELSUPP_STR "seclabel" +#define CONTEXT_STR "context" +#define FSCONTEXT_STR "fscontext" +#define ROOTCONTEXT_STR "rootcontext" +#define DEFCONTEXT_STR "defcontext" +#define SECLABEL_STR "seclabel" struct netlbl_lsm_secattr; -- cgit v1.2.3-59-g8ed1b From 0b52075ee62301dd150c9f2c3ddd0035ed894cde Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 23 Dec 2018 16:02:47 -0500 Subject: introduce cloning of fs_context new primitive: vfs_dup_fs_context(). Comes with fs_context method (->dup()) for copying the filesystem-specific parts of fs_context, along with LSM one (->fs_context_dup()) for doing the same to LSM parts. [needs better commit message, and change of Author:, anyway] Signed-off-by: Al Viro --- fs/fs_context.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++ include/linux/fs_context.h | 2 ++ include/linux/lsm_hooks.h | 7 +++++ include/linux/security.h | 6 +++++ security/security.c | 5 ++++ security/selinux/hooks.c | 39 +++++++++++++++++++++++++++ security/smack/smack_lsm.c | 49 +++++++++++++++++++++++++++++++++ 7 files changed, 175 insertions(+) (limited to 'security/selinux') diff --git a/fs/fs_context.c b/fs/fs_context.c index aa7e0ffb591a..57f61833ac83 100644 --- a/fs/fs_context.c +++ b/fs/fs_context.c @@ -337,6 +337,47 @@ void fc_drop_locked(struct fs_context *fc) static void legacy_fs_context_free(struct fs_context *fc); +/** + * vfs_dup_fc_config: Duplicate a filesystem context. + * @src_fc: The context to copy. + */ +struct fs_context *vfs_dup_fs_context(struct fs_context *src_fc) +{ + struct fs_context *fc; + int ret; + + if (!src_fc->ops->dup) + return ERR_PTR(-EOPNOTSUPP); + + fc = kmemdup(src_fc, sizeof(struct fs_context), GFP_KERNEL); + if (!fc) + return ERR_PTR(-ENOMEM); + + fc->fs_private = NULL; + fc->s_fs_info = NULL; + fc->source = NULL; + fc->security = NULL; + get_filesystem(fc->fs_type); + get_net(fc->net_ns); + get_user_ns(fc->user_ns); + get_cred(fc->cred); + + /* Can't call put until we've called ->dup */ + ret = fc->ops->dup(fc, src_fc); + if (ret < 0) + goto err_fc; + + ret = security_fs_context_dup(fc, src_fc); + if (ret < 0) + goto err_fc; + return fc; + +err_fc: + put_fs_context(fc); + return ERR_PTR(ret); +} +EXPORT_SYMBOL(vfs_dup_fs_context); + /** * put_fs_context - Dispose of a superblock configuration context. * @fc: The context to dispose of. @@ -380,6 +421,31 @@ static void legacy_fs_context_free(struct fs_context *fc) } } +/* + * Duplicate a legacy config. + */ +static int legacy_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc) +{ + struct legacy_fs_context *ctx; + struct legacy_fs_context *src_ctx = src_fc->fs_private; + + ctx = kmemdup(src_ctx, sizeof(*src_ctx), GFP_KERNEL); + if (!ctx) + return -ENOMEM; + + if (ctx->param_type == LEGACY_FS_INDIVIDUAL_PARAMS) { + ctx->legacy_data = kmemdup(src_ctx->legacy_data, + src_ctx->data_size, GFP_KERNEL); + if (!ctx->legacy_data) { + kfree(ctx); + return -ENOMEM; + } + } + + fc->fs_private = ctx; + return 0; +} + /* * Add a parameter to a legacy config. We build up a comma-separated list of * options. @@ -514,6 +580,7 @@ static int legacy_reconfigure(struct fs_context *fc) const struct fs_context_operations legacy_fs_context_ops = { .free = legacy_fs_context_free, + .dup = legacy_fs_context_dup, .parse_param = legacy_parse_param, .parse_monolithic = legacy_parse_monolithic, .get_tree = legacy_get_tree, diff --git a/include/linux/fs_context.h b/include/linux/fs_context.h index b1a95db7a111..0db0b645c7b8 100644 --- a/include/linux/fs_context.h +++ b/include/linux/fs_context.h @@ -94,6 +94,7 @@ struct fs_context { struct fs_context_operations { void (*free)(struct fs_context *fc); + int (*dup)(struct fs_context *fc, struct fs_context *src_fc); int (*parse_param)(struct fs_context *fc, struct fs_parameter *param); int (*parse_monolithic)(struct fs_context *fc, void *data); int (*get_tree)(struct fs_context *fc); @@ -111,6 +112,7 @@ extern struct fs_context *fs_context_for_reconfigure(struct dentry *dentry, extern struct fs_context *fs_context_for_submount(struct file_system_type *fs_type, struct dentry *reference); +extern struct fs_context *vfs_dup_fs_context(struct fs_context *fc); extern int vfs_parse_fs_param(struct fs_context *fc, struct fs_parameter *param); extern int vfs_parse_fs_string(struct fs_context *fc, const char *key, const char *value, size_t v_size); diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 47ba4db4d8fb..356e78fe90a8 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -79,6 +79,11 @@ * Security hooks for mount using fs_context. * [See also Documentation/filesystems/mounting.txt] * + * @fs_context_dup: + * Allocate and attach a security structure to sc->security. This pointer + * is initialised to NULL by the caller. + * @fc indicates the new filesystem context. + * @src_fc indicates the original filesystem context. * @fs_context_parse_param: * Userspace provided a parameter to configure a superblock. The LSM may * reject it with an error and may use it for itself, in which case it @@ -1470,6 +1475,7 @@ union security_list_options { void (*bprm_committing_creds)(struct linux_binprm *bprm); void (*bprm_committed_creds)(struct linux_binprm *bprm); + int (*fs_context_dup)(struct fs_context *fc, struct fs_context *src_sc); int (*fs_context_parse_param)(struct fs_context *fc, struct fs_parameter *param); int (*sb_alloc_security)(struct super_block *sb); @@ -1813,6 +1819,7 @@ struct security_hook_heads { struct hlist_head bprm_check_security; struct hlist_head bprm_committing_creds; struct hlist_head bprm_committed_creds; + struct hlist_head fs_context_dup; struct hlist_head fs_context_parse_param; struct hlist_head sb_alloc_security; struct hlist_head sb_free_security; diff --git a/include/linux/security.h b/include/linux/security.h index 2da9336a987e..f28a1ebfd78e 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -223,6 +223,7 @@ int security_bprm_set_creds(struct linux_binprm *bprm); int security_bprm_check(struct linux_binprm *bprm); void security_bprm_committing_creds(struct linux_binprm *bprm); void security_bprm_committed_creds(struct linux_binprm *bprm); +int security_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc); int security_fs_context_parse_param(struct fs_context *fc, struct fs_parameter *param); int security_sb_alloc(struct super_block *sb); void security_sb_free(struct super_block *sb); @@ -521,6 +522,11 @@ static inline void security_bprm_committed_creds(struct linux_binprm *bprm) { } +static inline int security_fs_context_dup(struct fs_context *fc, + struct fs_context *src_fc) +{ + return 0; +} static inline int security_fs_context_parse_param(struct fs_context *fc, struct fs_parameter *param) { diff --git a/security/security.c b/security/security.c index e5519488327d..5759339319dc 100644 --- a/security/security.c +++ b/security/security.c @@ -374,6 +374,11 @@ void security_bprm_committed_creds(struct linux_binprm *bprm) call_void_hook(bprm_committed_creds, bprm); } +int security_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc) +{ + return call_int_hook(fs_context_dup, 0, fc, src_fc); +} + int security_fs_context_parse_param(struct fs_context *fc, struct fs_parameter *param) { return call_int_hook(fs_context_parse_param, -ENOPARAM, fc, param); diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index f99381e97d73..4ba83de5fa80 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2764,6 +2764,44 @@ static int selinux_umount(struct vfsmount *mnt, int flags) FILESYSTEM__UNMOUNT, NULL); } +static int selinux_fs_context_dup(struct fs_context *fc, + struct fs_context *src_fc) +{ + const struct selinux_mnt_opts *src = src_fc->security; + struct selinux_mnt_opts *opts; + + if (!src) + return 0; + + fc->security = kzalloc(sizeof(struct selinux_mnt_opts), GFP_KERNEL); + if (!fc->security) + return -ENOMEM; + + opts = fc->security; + + if (src->fscontext) { + opts->fscontext = kstrdup(src->fscontext, GFP_KERNEL); + if (!opts->fscontext) + return -ENOMEM; + } + if (src->context) { + opts->context = kstrdup(src->context, GFP_KERNEL); + if (!opts->context) + return -ENOMEM; + } + if (src->rootcontext) { + opts->rootcontext = kstrdup(src->rootcontext, GFP_KERNEL); + if (!opts->rootcontext) + return -ENOMEM; + } + if (src->defcontext) { + opts->defcontext = kstrdup(src->defcontext, GFP_KERNEL); + if (!opts->defcontext) + return -ENOMEM; + } + return 0; +} + static const struct fs_parameter_spec selinux_param_specs[] = { fsparam_string(CONTEXT_STR, Opt_context), fsparam_string(DEFCONTEXT_STR, Opt_defcontext), @@ -6745,6 +6783,7 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(bprm_committing_creds, selinux_bprm_committing_creds), LSM_HOOK_INIT(bprm_committed_creds, selinux_bprm_committed_creds), + LSM_HOOK_INIT(fs_context_dup, selinux_fs_context_dup), LSM_HOOK_INIT(fs_context_parse_param, selinux_fs_context_parse_param), LSM_HOOK_INIT(sb_alloc_security, selinux_sb_alloc_security), diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 5f93c4f84384..03176f600a87 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -647,6 +647,54 @@ out_opt_err: return -EINVAL; } +/** + * smack_fs_context_dup - Duplicate the security data on fs_context duplication + * @fc: The new filesystem context. + * @src_fc: The source filesystem context being duplicated. + * + * Returns 0 on success or -ENOMEM on error. + */ +static int smack_fs_context_dup(struct fs_context *fc, + struct fs_context *src_fc) +{ + struct smack_mnt_opts *dst, *src = src_fc->security; + + if (!src) + return 0; + + fc->security = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL); + if (!fc->security) + return -ENOMEM; + dst = fc->security; + + if (src->fsdefault) { + dst->fsdefault = kstrdup(src->fsdefault, GFP_KERNEL); + if (!dst->fsdefault) + return -ENOMEM; + } + if (src->fsfloor) { + dst->fsfloor = kstrdup(src->fsfloor, GFP_KERNEL); + if (!dst->fsfloor) + return -ENOMEM; + } + if (src->fshat) { + dst->fshat = kstrdup(src->fshat, GFP_KERNEL); + if (!dst->fshat) + return -ENOMEM; + } + if (src->fsroot) { + dst->fsroot = kstrdup(src->fsroot, GFP_KERNEL); + if (!dst->fsroot) + return -ENOMEM; + } + if (src->fstransmute) { + dst->fstransmute = kstrdup(src->fstransmute, GFP_KERNEL); + if (!dst->fstransmute) + return -ENOMEM; + } + return 0; +} + static const struct fs_parameter_spec smack_param_specs[] = { fsparam_string("fsdefault", Opt_fsdefault), fsparam_string("fsfloor", Opt_fsfloor), @@ -4626,6 +4674,7 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(ptrace_traceme, smack_ptrace_traceme), LSM_HOOK_INIT(syslog, smack_syslog), + LSM_HOOK_INIT(fs_context_dup, smack_fs_context_dup), LSM_HOOK_INIT(fs_context_parse_param, smack_fs_context_parse_param), LSM_HOOK_INIT(sb_alloc_security, smack_sb_alloc_security), -- cgit v1.2.3-59-g8ed1b