From 7898e1f8e9eb1bee88c92d636e0ab93f2cbe31c6 Mon Sep 17 00:00:00 2001 From: Casey Schaufler Date: Mon, 17 Jan 2011 08:05:27 -0800 Subject: Subject: [PATCH] Smack: mmap controls for library containment In the embedded world there are often situations where libraries are updated from a variety of sources, for a variety of reasons, and with any number of security characteristics. These differences might include privilege required for a given library provided interface to function properly, as occurs from time to time in graphics libraries. There are also cases where it is important to limit use of libraries based on the provider of the library and the security aware application may make choices based on that criteria. These issues are addressed by providing an additional Smack label that may optionally be assigned to an object, the SMACK64MMAP attribute. An mmap operation is allowed if there is no such attribute. If there is a SMACK64MMAP attribute the mmap is permitted only if a subject with that label has all of the access permitted a subject with the current task label. Security aware applications may from time to time wish to reduce their "privilege" to avoid accidental use of privilege. One case where this arises is the environment in which multiple sources provide libraries to perform the same functions. An application may know that it should eschew services made available from a particular vendor, or of a particular version. In support of this a secondary list of Smack rules has been added that is local to the task. This list is consulted only in the case where the global list has approved access. It can only further restrict access. Unlike the global last, if no entry is found on the local list access is granted. An application can add entries to its own list by writing to /smack/load-self. The changes appear large as they involve refactoring the list handling to accomodate there being more than one rule list. Signed-off-by: Casey Schaufler --- include/linux/xattr.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include') diff --git a/include/linux/xattr.h b/include/linux/xattr.h index e6131ef98d8f..6050783005bd 100644 --- a/include/linux/xattr.h +++ b/include/linux/xattr.h @@ -42,11 +42,13 @@ #define XATTR_SMACK_IPOUT "SMACK64IPOUT" #define XATTR_SMACK_EXEC "SMACK64EXEC" #define XATTR_SMACK_TRANSMUTE "SMACK64TRANSMUTE" +#define XATTR_SMACK_MMAP "SMACK64MMAP" #define XATTR_NAME_SMACK XATTR_SECURITY_PREFIX XATTR_SMACK_SUFFIX #define XATTR_NAME_SMACKIPIN XATTR_SECURITY_PREFIX XATTR_SMACK_IPIN #define XATTR_NAME_SMACKIPOUT XATTR_SECURITY_PREFIX XATTR_SMACK_IPOUT #define XATTR_NAME_SMACKEXEC XATTR_SECURITY_PREFIX XATTR_SMACK_EXEC #define XATTR_NAME_SMACKTRANSMUTE XATTR_SECURITY_PREFIX XATTR_SMACK_TRANSMUTE +#define XATTR_NAME_SMACKMMAP XATTR_SECURITY_PREFIX XATTR_SMACK_MMAP #define XATTR_CAPS_SUFFIX "capability" #define XATTR_NAME_CAPS XATTR_SECURITY_PREFIX XATTR_CAPS_SUFFIX -- cgit v1.2.3 From 2a7dba391e5628ad665ce84ef9a6648da541ebab Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Tue, 1 Feb 2011 11:05:39 -0500 Subject: fs/vfs/security: pass last path component to LSM on inode creation SELinux would like to implement a new labeling behavior of newly created inodes. We currently label new inodes based on the parent and the creating process. This new behavior would also take into account the name of the new object when deciding the new label. This is not the (supposed) full path, just the last component of the path. This is very useful because creating /etc/shadow is different than creating /etc/passwd but the kernel hooks are unable to differentiate these operations. We currently require that userspace realize it is doing some difficult operation like that and than userspace jumps through SELinux hoops to get things set up correctly. This patch does not implement new behavior, that is obviously contained in a seperate SELinux patch, but it does pass the needed name down to the correct LSM hook. If no such name exists it is fine to pass NULL. Signed-off-by: Eric Paris --- include/linux/ext3_fs.h | 3 ++- include/linux/reiserfs_xattr.h | 2 ++ include/linux/security.h | 9 +++++++-- 3 files changed, 11 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/linux/ext3_fs.h b/include/linux/ext3_fs.h index 6ce1bca01724..87312a81daba 100644 --- a/include/linux/ext3_fs.h +++ b/include/linux/ext3_fs.h @@ -874,7 +874,8 @@ extern int ext3fs_dirhash(const char *name, int len, struct dx_hash_info *hinfo); /* ialloc.c */ -extern struct inode * ext3_new_inode (handle_t *, struct inode *, int); +extern struct inode * ext3_new_inode (handle_t *, struct inode *, + const struct qstr *, int); extern void ext3_free_inode (handle_t *, struct inode *); extern struct inode * ext3_orphan_get (struct super_block *, unsigned long); extern unsigned long ext3_count_free_inodes (struct super_block *); diff --git a/include/linux/reiserfs_xattr.h b/include/linux/reiserfs_xattr.h index 3b94c91f20a6..6deef5dc95fb 100644 --- a/include/linux/reiserfs_xattr.h +++ b/include/linux/reiserfs_xattr.h @@ -63,6 +63,7 @@ extern const struct xattr_handler reiserfs_xattr_trusted_handler; extern const struct xattr_handler reiserfs_xattr_security_handler; #ifdef CONFIG_REISERFS_FS_SECURITY int reiserfs_security_init(struct inode *dir, struct inode *inode, + const struct qstr *qstr, struct reiserfs_security_handle *sec); int reiserfs_security_write(struct reiserfs_transaction_handle *th, struct inode *inode, @@ -130,6 +131,7 @@ static inline void reiserfs_init_xattr_rwsem(struct inode *inode) #ifndef CONFIG_REISERFS_FS_SECURITY static inline int reiserfs_security_init(struct inode *dir, struct inode *inode, + const struct qstr *qstr, struct reiserfs_security_handle *sec) { return 0; diff --git a/include/linux/security.h b/include/linux/security.h index c642bb8b8f5a..05dd5a64aa76 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -25,6 +25,7 @@ #include #include #include +#include #include #include #include @@ -315,6 +316,7 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * then it should return -EOPNOTSUPP to skip this processing. * @inode contains the inode structure of the newly created inode. * @dir contains the inode structure of the parent directory. + * @qstr contains the last path component of the new object * @name will be set to the allocated name suffix (e.g. selinux). * @value will be set to the allocated attribute value. * @len will be set to the length of the value. @@ -1435,7 +1437,8 @@ struct security_operations { int (*inode_alloc_security) (struct inode *inode); void (*inode_free_security) (struct inode *inode); int (*inode_init_security) (struct inode *inode, struct inode *dir, - char **name, void **value, size_t *len); + const struct qstr *qstr, char **name, + void **value, size_t *len); int (*inode_create) (struct inode *dir, struct dentry *dentry, int mode); int (*inode_link) (struct dentry *old_dentry, @@ -1696,7 +1699,8 @@ int security_sb_parse_opts_str(char *options, struct security_mnt_opts *opts); int security_inode_alloc(struct inode *inode); void security_inode_free(struct inode *inode); int security_inode_init_security(struct inode *inode, struct inode *dir, - char **name, void **value, size_t *len); + const struct qstr *qstr, char **name, + void **value, size_t *len); int security_inode_create(struct inode *dir, struct dentry *dentry, int mode); int security_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry); @@ -2023,6 +2027,7 @@ static inline void security_inode_free(struct inode *inode) static inline int security_inode_init_security(struct inode *inode, struct inode *dir, + const struct qstr *qstr, char **name, void **value, size_t *len) -- cgit v1.2.3 From 4916ca401e3051dad326ddd69765bd0e3f32fb9b Mon Sep 17 00:00:00 2001 From: Lucian Adrian Grijincu Date: Tue, 1 Feb 2011 18:44:56 +0200 Subject: security: remove unused security_sysctl hook The only user for this hook was selinux. sysctl routes every call through /proc/sys/. Selinux and other security modules use the file system checks for sysctl too, so no need for this hook any more. Signed-off-by: Lucian Adrian Grijincu Signed-off-by: Eric Paris --- include/linux/security.h | 13 ------------- 1 file changed, 13 deletions(-) (limited to 'include') diff --git a/include/linux/security.h b/include/linux/security.h index 05dd5a64aa76..14167f2eb35a 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -1259,12 +1259,6 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * @cap contains the capability . * @audit: Whether to write an audit message or not * Return 0 if the capability is granted for @tsk. - * @sysctl: - * Check permission before accessing the @table sysctl variable in the - * manner specified by @op. - * @table contains the ctl_table structure for the sysctl variable. - * @op contains the operation (001 = search, 002 = write, 004 = read). - * Return 0 if permission is granted. * @syslog: * Check permission before accessing the kernel message ring or changing * logging to the console. @@ -1385,7 +1379,6 @@ struct security_operations { const kernel_cap_t *permitted); int (*capable) (struct task_struct *tsk, const struct cred *cred, int cap, int audit); - int (*sysctl) (struct ctl_table *table, int op); int (*quotactl) (int cmds, int type, int id, struct super_block *sb); int (*quota_on) (struct dentry *dentry); int (*syslog) (int type); @@ -1668,7 +1661,6 @@ int security_capset(struct cred *new, const struct cred *old, int security_capable(int cap); int security_real_capable(struct task_struct *tsk, int cap); int security_real_capable_noaudit(struct task_struct *tsk, int cap); -int security_sysctl(struct ctl_table *table, int op); int security_quotactl(int cmds, int type, int id, struct super_block *sb); int security_quota_on(struct dentry *dentry); int security_syslog(int type); @@ -1887,11 +1879,6 @@ int security_real_capable_noaudit(struct task_struct *tsk, int cap) return ret; } -static inline int security_sysctl(struct ctl_table *table, int op) -{ - return 0; -} - static inline int security_quotactl(int cmds, int type, int id, struct super_block *sb) { -- cgit v1.2.3 From a68a27b6f2354273bacc39c3dd06456edb202230 Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Tue, 2 Nov 2010 10:10:56 -0400 Subject: IMA: convert i_readcount to atomic Convert the inode's i_readcount from an unsigned int to atomic. Signed-off-by: Mimi Zohar Acked-by: Eric Paris --- include/linux/fs.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/fs.h b/include/linux/fs.h index baf3e556ff0e..ef85322863b9 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -794,8 +794,7 @@ struct inode { #endif #ifdef CONFIG_IMA - /* protected by i_lock */ - unsigned int i_readcount; /* struct files open RO */ + atomic_t i_readcount; /* struct files open RO */ #endif atomic_t i_writecount; #ifdef CONFIG_SECURITY -- cgit v1.2.3 From a5c96ebf1d71df0c5fb77ab58c9aeb307cf02372 Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Tue, 2 Nov 2010 10:11:37 -0400 Subject: IMA: define readcount functions Define i_readcount_inc/dec() functions to be called from the VFS layer. Changelog: - renamed iget/iput_readcount to i_readcount_inc/dec (Dave Chinner's suggestion) - removed i_lock in iput_readcount() (based on comments:Dave Chinner,Eric Paris) Signed-off-by: Mimi Zohar Acked-by: Eric Paris --- include/linux/fs.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'include') diff --git a/include/linux/fs.h b/include/linux/fs.h index ef85322863b9..a3e8f02b727d 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2186,6 +2186,26 @@ static inline void allow_write_access(struct file *file) if (file) atomic_inc(&file->f_path.dentry->d_inode->i_writecount); } +#ifdef CONFIG_IMA +static inline void i_readcount_dec(struct inode *inode) +{ + BUG_ON(!atomic_read(&inode->i_readcount)); + atomic_dec(&inode->i_readcount); +} +static inline void i_readcount_inc(struct inode *inode) +{ + atomic_inc(&inode->i_readcount); +} +#else +static inline void i_readcount_dec(struct inode *inode) +{ + return; +} +static inline void i_readcount_inc(struct inode *inode) +{ + return; +} +#endif extern int do_pipe_flags(int *, int); extern struct file *create_read_pipe(struct file *f, int flags); extern struct file *create_write_pipe(int flags); -- cgit v1.2.3 From 890275b5eb79e9933d12290473eab9ac38da0051 Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Tue, 2 Nov 2010 10:13:07 -0400 Subject: IMA: maintain i_readcount in the VFS layer ima_counts_get() updated the readcount and invalidated the PCR, as necessary. Only update the i_readcount in the VFS layer. Move the PCR invalidation checks to ima_file_check(), where it belongs. Maintaining the i_readcount in the VFS layer, will allow other subsystems to use i_readcount. Signed-off-by: Mimi Zohar Acked-by: Eric Paris --- include/linux/ima.h | 6 ------ 1 file changed, 6 deletions(-) (limited to 'include') diff --git a/include/linux/ima.h b/include/linux/ima.h index 975837e7d6c0..09e6e62f9953 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -20,7 +20,6 @@ extern void ima_inode_free(struct inode *inode); extern int ima_file_check(struct file *file, int mask); extern void ima_file_free(struct file *file); extern int ima_file_mmap(struct file *file, unsigned long prot); -extern void ima_counts_get(struct file *file); #else static inline int ima_bprm_check(struct linux_binprm *bprm) @@ -53,10 +52,5 @@ static inline int ima_file_mmap(struct file *file, unsigned long prot) return 0; } -static inline void ima_counts_get(struct file *file) -{ - return; -} - #endif /* CONFIG_IMA_H */ #endif /* _LINUX_IMA_H */ -- cgit v1.2.3 From ff36fe2c845cab2102e4826c1ffa0a6ebf487c65 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Thu, 3 Mar 2011 16:09:14 -0500 Subject: LSM: Pass -o remount options to the LSM The VFS mount code passes the mount options to the LSM. The LSM will remove options it understands from the data and the VFS will then pass the remaining options onto the underlying filesystem. This is how options like the SELinux context= work. The problem comes in that -o remount never calls into LSM code. So if you include an LSM specific option it will get passed to the filesystem and will cause the remount to fail. An example of where this is a problem is the 'seclabel' option. The SELinux LSM hook will print this word in /proc/mounts if the filesystem is being labeled using xattrs. If you pass this word on mount it will be silently stripped and ignored. But if you pass this word on remount the LSM never gets called and it will be passed to the FS. The FS doesn't know what seclabel means and thus should fail the mount. For example an ext3 fs mounted over loop # mount -o loop /tmp/fs /mnt/tmp # cat /proc/mounts | grep /mnt/tmp /dev/loop0 /mnt/tmp ext3 rw,seclabel,relatime,errors=continue,barrier=0,data=ordered 0 0 # mount -o remount /mnt/tmp mount: /mnt/tmp not mounted already, or bad option # dmesg EXT3-fs (loop0): error: unrecognized mount option "seclabel" or missing value This patch passes the remount mount options to an new LSM hook. Signed-off-by: Eric Paris Reviewed-by: James Morris --- include/linux/security.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'include') diff --git a/include/linux/security.h b/include/linux/security.h index 14167f2eb35a..d11ac43ecc49 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -268,6 +268,12 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * @orig the original mount data copied from userspace. * @copy copied data which will be passed to the security module. * Returns 0 if the copy was successful. + * @sb_remount: + * Extracts security system specifc mount options and verifys no changes + * are being made to those options. + * @sb superblock being remounted + * @data contains the filesystem-specific data. + * Return 0 if permission is granted. * @sb_umount: * Check permission before the @mnt file system is unmounted. * @mnt contains the mounted file system. @@ -1394,6 +1400,7 @@ struct security_operations { int (*sb_alloc_security) (struct super_block *sb); void (*sb_free_security) (struct super_block *sb); int (*sb_copy_data) (char *orig, char *copy); + int (*sb_remount) (struct super_block *sb, void *data); int (*sb_kern_mount) (struct super_block *sb, int flags, void *data); int (*sb_show_options) (struct seq_file *m, struct super_block *sb); int (*sb_statfs) (struct dentry *dentry); @@ -1676,6 +1683,7 @@ int security_bprm_secureexec(struct linux_binprm *bprm); 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_remount(struct super_block *sb, void *data); int security_sb_kern_mount(struct super_block *sb, int flags, void *data); int security_sb_show_options(struct seq_file *m, struct super_block *sb); int security_sb_statfs(struct dentry *dentry); @@ -1955,6 +1963,11 @@ static inline int security_sb_copy_data(char *orig, char *copy) return 0; } +static inline int security_sb_remount(struct super_block *sb, void *data) +{ + return 0; +} + static inline int security_sb_kern_mount(struct super_block *sb, int flags, void *data) { return 0; -- cgit v1.2.3 From 633e804e89464d3875e59de1959a53f9041d3094 Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 7 Mar 2011 15:05:51 +0000 Subject: KEYS: Add an RCU payload dereference macro Add an RCU payload dereference macro as this seems to be a common piece of code amongst key types that use RCU referenced payloads. Signed-off-by: David Howells Signed-off-by: Mimi Zohar Signed-off-by: James Morris --- include/linux/key.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include') diff --git a/include/linux/key.h b/include/linux/key.h index 3db0adce1fda..a6b1edcffc34 100644 --- a/include/linux/key.h +++ b/include/linux/key.h @@ -275,6 +275,10 @@ static inline key_serial_t key_serial(struct key *key) return key ? key->serial : 0; } +#define rcu_dereference_key(KEY) \ + (rcu_dereference_protected((KEY)->payload.rcudata, \ + rwsem_is_locked(&((struct key *)(KEY))->sem))) + #ifdef CONFIG_SYSCTL extern ctl_table key_sysctls[]; #endif -- cgit v1.2.3 From b9fffa3877a3ebbe0a5ad5a247358e2f7df15b24 Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 7 Mar 2011 15:05:59 +0000 Subject: KEYS: Add a key type op to permit the key description to be vetted Add a key type operation to permit the key type to vet the description of a new key that key_alloc() is about to allocate. The operation may reject the description if it wishes with an error of its choosing. If it does this, the key will not be allocated. Signed-off-by: David Howells Reviewed-by: Mimi Zohar Signed-off-by: James Morris --- include/linux/key-type.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include') diff --git a/include/linux/key-type.h b/include/linux/key-type.h index 65833d4d5998..fc8525e838b7 100644 --- a/include/linux/key-type.h +++ b/include/linux/key-type.h @@ -41,6 +41,9 @@ struct key_type { */ size_t def_datalen; + /* vet a description */ + int (*vet_description)(const char *description); + /* instantiate a key of this type * - this method should call key_payload_reserve() to determine if the * user's quota will hold the payload -- cgit v1.2.3 From fdd1b94581782a2ddf9124414e5b7a5f48ce2f9c Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 7 Mar 2011 15:06:09 +0000 Subject: KEYS: Add a new keyctl op to reject a key with a specified error code Add a new keyctl op to reject a key with a specified error code. This works much the same as negating a key, and so keyctl_negate_key() is made a special case of keyctl_reject_key(). The difference is that keyctl_negate_key() selects ENOKEY as the error to be reported. Typically the key would be rejected with EKEYEXPIRED, EKEYREVOKED or EKEYREJECTED, but this is not mandatory. Signed-off-by: David Howells Signed-off-by: James Morris --- include/linux/key-type.h | 11 ++++++++++- include/linux/key.h | 1 + include/linux/keyctl.h | 1 + 3 files changed, 12 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/key-type.h b/include/linux/key-type.h index fc8525e838b7..9efd081bb31e 100644 --- a/include/linux/key-type.h +++ b/include/linux/key-type.h @@ -105,11 +105,20 @@ extern int key_instantiate_and_link(struct key *key, size_t datalen, struct key *keyring, struct key *instkey); -extern int key_negate_and_link(struct key *key, +extern int key_reject_and_link(struct key *key, unsigned timeout, + unsigned error, struct key *keyring, struct key *instkey); extern void complete_request_key(struct key_construction *cons, int error); +static inline int key_negate_and_link(struct key *key, + unsigned timeout, + struct key *keyring, + struct key *instkey) +{ + return key_reject_and_link(key, timeout, ENOKEY, keyring, instkey); +} + #endif /* CONFIG_KEYS */ #endif /* _LINUX_KEY_TYPE_H */ diff --git a/include/linux/key.h b/include/linux/key.h index a6b1edcffc34..b2bb01719561 100644 --- a/include/linux/key.h +++ b/include/linux/key.h @@ -170,6 +170,7 @@ struct key { struct list_head link; unsigned long x[2]; void *p[2]; + int reject_error; } type_data; /* key data diff --git a/include/linux/keyctl.h b/include/linux/keyctl.h index bd383f1944fb..7022974def0c 100644 --- a/include/linux/keyctl.h +++ b/include/linux/keyctl.h @@ -53,5 +53,6 @@ #define KEYCTL_ASSUME_AUTHORITY 16 /* assume request_key() authorisation */ #define KEYCTL_GET_SECURITY 17 /* get key security label */ #define KEYCTL_SESSION_TO_PARENT 18 /* apply session keyring to parent process */ +#define KEYCTL_REJECT 19 /* reject a partially constructed key */ #endif /* _LINUX_KEYCTL_H */ -- cgit v1.2.3 From ee009e4a0d4555ed522a631bae9896399674f064 Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 7 Mar 2011 15:06:20 +0000 Subject: KEYS: Add an iovec version of KEYCTL_INSTANTIATE Add a keyctl op (KEYCTL_INSTANTIATE_IOV) that is like KEYCTL_INSTANTIATE, but takes an iovec array and concatenates the data in-kernel into one buffer. Since the KEYCTL_INSTANTIATE copies the data anyway, this isn't too much of a problem. Signed-off-by: David Howells Signed-off-by: James Morris --- include/linux/keyctl.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/keyctl.h b/include/linux/keyctl.h index 7022974def0c..9b0b865ce622 100644 --- a/include/linux/keyctl.h +++ b/include/linux/keyctl.h @@ -54,5 +54,6 @@ #define KEYCTL_GET_SECURITY 17 /* get key security label */ #define KEYCTL_SESSION_TO_PARENT 18 /* apply session keyring to parent process */ #define KEYCTL_REJECT 19 /* reject a partially constructed key */ +#define KEYCTL_INSTANTIATE_IOV 20 /* instantiate a partially constructed key */ #endif /* _LINUX_KEYCTL_H */ -- cgit v1.2.3