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 --- security/capability.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'security/capability.c') diff --git a/security/capability.c b/security/capability.c index 2a5df2b7da83..383d14dc12ef 100644 --- a/security/capability.c +++ b/security/capability.c @@ -118,7 +118,8 @@ static void cap_inode_free_security(struct inode *inode) } static int cap_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) { return -EOPNOTSUPP; } -- 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 ------------- kernel/sysctl.c | 5 ----- security/capability.c | 6 ------ security/security.c | 5 ----- 4 files changed, 29 deletions(-) (limited to 'security/capability.c') 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) { diff --git a/kernel/sysctl.c b/kernel/sysctl.c index ae5cbb1e3ced..e24254c27eaf 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1691,13 +1691,8 @@ static int test_perm(int mode, int op) int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op) { - int error; int mode; - error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC)); - if (error) - return error; - if (root->permissions) mode = root->permissions(root, current->nsproxy, table); else diff --git a/security/capability.c b/security/capability.c index 383d14dc12ef..85b67c8632df 100644 --- a/security/capability.c +++ b/security/capability.c @@ -12,11 +12,6 @@ #include -static int cap_sysctl(ctl_table *table, int op) -{ - return 0; -} - static int cap_syslog(int type) { return 0; @@ -881,7 +876,6 @@ void __init security_fixup_ops(struct security_operations *ops) set_to_cap_if_null(ops, capable); set_to_cap_if_null(ops, quotactl); set_to_cap_if_null(ops, quota_on); - set_to_cap_if_null(ops, sysctl); set_to_cap_if_null(ops, syslog); set_to_cap_if_null(ops, settime); set_to_cap_if_null(ops, vm_enough_memory); diff --git a/security/security.c b/security/security.c index 4830f36e1ab5..8f28685ee0d9 100644 --- a/security/security.c +++ b/security/security.c @@ -182,11 +182,6 @@ int security_real_capable_noaudit(struct task_struct *tsk, int cap) return ret; } -int security_sysctl(struct ctl_table *table, int op) -{ - return security_ops->sysctl(table, op); -} - int security_quotactl(int cmds, int type, int id, struct super_block *sb) { return security_ops->quotactl(cmds, type, id, sb); -- cgit v1.2.3 From e33f770426674a565a188042caf3f974f8b3722d Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Tue, 22 Feb 2011 18:13:15 -0800 Subject: xfrm: Mark flowi arg to security_xfrm_state_pol_flow_match() const. Signed-off-by: David S. Miller --- include/linux/security.h | 7 ++++--- security/capability.c | 2 +- security/security.c | 3 ++- security/selinux/include/xfrm.h | 2 +- security/selinux/xfrm.c | 2 +- 5 files changed, 9 insertions(+), 7 deletions(-) (limited to 'security/capability.c') diff --git a/include/linux/security.h b/include/linux/security.h index b2b7f9749f5e..9b5f184a7f65 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -1623,7 +1623,7 @@ struct security_operations { int (*xfrm_policy_lookup) (struct xfrm_sec_ctx *ctx, u32 fl_secid, u8 dir); int (*xfrm_state_pol_flow_match) (struct xfrm_state *x, struct xfrm_policy *xp, - struct flowi *fl); + const struct flowi *fl); int (*xfrm_decode_session) (struct sk_buff *skb, u32 *secid, int ckall); #endif /* CONFIG_SECURITY_NETWORK_XFRM */ @@ -2761,7 +2761,8 @@ int security_xfrm_state_delete(struct xfrm_state *x); void security_xfrm_state_free(struct xfrm_state *x); int security_xfrm_policy_lookup(struct xfrm_sec_ctx *ctx, u32 fl_secid, u8 dir); int security_xfrm_state_pol_flow_match(struct xfrm_state *x, - struct xfrm_policy *xp, struct flowi *fl); + struct xfrm_policy *xp, + const struct flowi *fl); int security_xfrm_decode_session(struct sk_buff *skb, u32 *secid); void security_skb_classify_flow(struct sk_buff *skb, struct flowi *fl); @@ -2813,7 +2814,7 @@ static inline int security_xfrm_policy_lookup(struct xfrm_sec_ctx *ctx, u32 fl_s } static inline int security_xfrm_state_pol_flow_match(struct xfrm_state *x, - struct xfrm_policy *xp, struct flowi *fl) + struct xfrm_policy *xp, const struct flowi *fl) { return 1; } diff --git a/security/capability.c b/security/capability.c index 2a5df2b7da83..b8eeaee5c99e 100644 --- a/security/capability.c +++ b/security/capability.c @@ -760,7 +760,7 @@ static int cap_xfrm_policy_lookup(struct xfrm_sec_ctx *ctx, u32 sk_sid, u8 dir) static int cap_xfrm_state_pol_flow_match(struct xfrm_state *x, struct xfrm_policy *xp, - struct flowi *fl) + const struct flowi *fl) { return 1; } diff --git a/security/security.c b/security/security.c index 7b7308ace8c5..8ef1f7dff277 100644 --- a/security/security.c +++ b/security/security.c @@ -1233,7 +1233,8 @@ int security_xfrm_policy_lookup(struct xfrm_sec_ctx *ctx, u32 fl_secid, u8 dir) } int security_xfrm_state_pol_flow_match(struct xfrm_state *x, - struct xfrm_policy *xp, struct flowi *fl) + struct xfrm_policy *xp, + const struct flowi *fl) { return security_ops->xfrm_state_pol_flow_match(x, xp, fl); } diff --git a/security/selinux/include/xfrm.h b/security/selinux/include/xfrm.h index 13128f9a3e5a..b43813c9e049 100644 --- a/security/selinux/include/xfrm.h +++ b/security/selinux/include/xfrm.h @@ -19,7 +19,7 @@ void selinux_xfrm_state_free(struct xfrm_state *x); int selinux_xfrm_state_delete(struct xfrm_state *x); int selinux_xfrm_policy_lookup(struct xfrm_sec_ctx *ctx, u32 fl_secid, u8 dir); int selinux_xfrm_state_pol_flow_match(struct xfrm_state *x, - struct xfrm_policy *xp, struct flowi *fl); + struct xfrm_policy *xp, const struct flowi *fl); /* * Extract the security blob from the sock (it's actually on the socket) diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c index fff78d3b51a2..c43ab542246c 100644 --- a/security/selinux/xfrm.c +++ b/security/selinux/xfrm.c @@ -112,7 +112,7 @@ int selinux_xfrm_policy_lookup(struct xfrm_sec_ctx *ctx, u32 fl_secid, u8 dir) */ int selinux_xfrm_state_pol_flow_match(struct xfrm_state *x, struct xfrm_policy *xp, - struct flowi *fl) + const struct flowi *fl) { u32 state_sid; int rc; -- 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 --- fs/namespace.c | 4 ++++ include/linux/security.h | 13 +++++++++++++ security/capability.c | 6 ++++++ security/security.c | 5 +++++ 4 files changed, 28 insertions(+) (limited to 'security/capability.c') diff --git a/fs/namespace.c b/fs/namespace.c index 3ddfd9046c44..1b3f2ac59c5e 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1800,6 +1800,10 @@ static int do_remount(struct path *path, int flags, int mnt_flags, if (path->dentry != path->mnt->mnt_root) return -EINVAL; + err = security_sb_remount(sb, data); + if (err) + return err; + down_write(&sb->s_umount); if (flags & MS_BIND) err = change_mount_flags(path->mnt, flags); 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; diff --git a/security/capability.c b/security/capability.c index 85b67c8632df..ab3d807accc3 100644 --- a/security/capability.c +++ b/security/capability.c @@ -54,6 +54,11 @@ static int cap_sb_copy_data(char *orig, char *copy) return 0; } +static int cap_sb_remount(struct super_block *sb, void *data) +{ + return 0; +} + static int cap_sb_kern_mount(struct super_block *sb, int flags, void *data) { return 0; @@ -887,6 +892,7 @@ void __init security_fixup_ops(struct security_operations *ops) set_to_cap_if_null(ops, sb_alloc_security); set_to_cap_if_null(ops, sb_free_security); set_to_cap_if_null(ops, sb_copy_data); + set_to_cap_if_null(ops, sb_remount); set_to_cap_if_null(ops, sb_kern_mount); set_to_cap_if_null(ops, sb_show_options); set_to_cap_if_null(ops, sb_statfs); diff --git a/security/security.c b/security/security.c index 8f28685ee0d9..b1d6134548bc 100644 --- a/security/security.c +++ b/security/security.c @@ -267,6 +267,11 @@ int security_sb_copy_data(char *orig, char *copy) } EXPORT_SYMBOL(security_sb_copy_data); +int security_sb_remount(struct super_block *sb, void *data) +{ + return security_ops->sb_remount(sb, data); +} + int security_sb_kern_mount(struct super_block *sb, int flags, void *data) { return security_ops->sb_kern_mount(sb, flags, data); -- cgit v1.2.3 From 8c9e80ed276fc4b9c9fadf29d8bf6b3576112f1a Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Thu, 21 Apr 2011 17:23:19 -0700 Subject: SECURITY: Move exec_permission RCU checks into security modules Right now all RCU walks fall back to reference walk when CONFIG_SECURITY is enabled, even though just the standard capability module is active. This is because security_inode_exec_permission unconditionally fails RCU walks. Move this decision to the low level security module. This requires passing the RCU flags down the security hook. This way at least the capability module and a few easy cases in selinux/smack work with RCU walks with CONFIG_SECURITY=y Signed-off-by: Andi Kleen Acked-by: Eric Paris Signed-off-by: Linus Torvalds --- include/linux/security.h | 2 +- security/capability.c | 2 +- security/security.c | 6 ++---- security/selinux/hooks.c | 6 +++++- security/smack/smack_lsm.c | 6 +++++- 5 files changed, 14 insertions(+), 8 deletions(-) (limited to 'security/capability.c') diff --git a/include/linux/security.h b/include/linux/security.h index ca02f1716736..8ce59ef3e5af 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -1456,7 +1456,7 @@ struct security_operations { struct inode *new_dir, struct dentry *new_dentry); int (*inode_readlink) (struct dentry *dentry); int (*inode_follow_link) (struct dentry *dentry, struct nameidata *nd); - int (*inode_permission) (struct inode *inode, int mask); + int (*inode_permission) (struct inode *inode, int mask, unsigned flags); int (*inode_setattr) (struct dentry *dentry, struct iattr *attr); int (*inode_getattr) (struct vfsmount *mnt, struct dentry *dentry); int (*inode_setxattr) (struct dentry *dentry, const char *name, diff --git a/security/capability.c b/security/capability.c index 2984ea4f776f..bbb51156261b 100644 --- a/security/capability.c +++ b/security/capability.c @@ -181,7 +181,7 @@ static int cap_inode_follow_link(struct dentry *dentry, return 0; } -static int cap_inode_permission(struct inode *inode, int mask) +static int cap_inode_permission(struct inode *inode, int mask, unsigned flags) { return 0; } diff --git a/security/security.c b/security/security.c index 101142369db4..4ba6d4cc061f 100644 --- a/security/security.c +++ b/security/security.c @@ -518,16 +518,14 @@ int security_inode_permission(struct inode *inode, int mask) { if (unlikely(IS_PRIVATE(inode))) return 0; - return security_ops->inode_permission(inode, mask); + return security_ops->inode_permission(inode, mask, 0); } int security_inode_exec_permission(struct inode *inode, unsigned int flags) { if (unlikely(IS_PRIVATE(inode))) return 0; - if (flags) - return -ECHILD; - return security_ops->inode_permission(inode, MAY_EXEC); + return security_ops->inode_permission(inode, MAY_EXEC, flags); } int security_inode_setattr(struct dentry *dentry, struct iattr *attr) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index f9c3764e4859..a73f4e463774 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2635,7 +2635,7 @@ static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *na return dentry_has_perm(cred, NULL, dentry, FILE__READ); } -static int selinux_inode_permission(struct inode *inode, int mask) +static int selinux_inode_permission(struct inode *inode, int mask, unsigned flags) { const struct cred *cred = current_cred(); struct common_audit_data ad; @@ -2649,6 +2649,10 @@ static int selinux_inode_permission(struct inode *inode, int mask) if (!mask) return 0; + /* May be droppable after audit */ + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + COMMON_AUDIT_DATA_INIT(&ad, FS); ad.u.fs.inode = inode; diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index c6f8fcadae07..400a5d5cde61 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -686,7 +686,7 @@ static int smack_inode_rename(struct inode *old_inode, * * Returns 0 if access is permitted, -EACCES otherwise */ -static int smack_inode_permission(struct inode *inode, int mask) +static int smack_inode_permission(struct inode *inode, int mask, unsigned flags) { struct smk_audit_info ad; @@ -696,6 +696,10 @@ static int smack_inode_permission(struct inode *inode, int mask) */ if (mask == 0) return 0; + + /* May be droppable after audit */ + if (flags & IPERM_FLAG_RCU) + return -ECHILD; smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS); smk_ad_setfield_u_fs_inode(&ad, inode); return smk_curacc(smk_of_inode(inode), mask, &ad); -- cgit v1.2.3