diff options
| -rw-r--r-- | include/linux/capability.h | 15 | ||||
| -rw-r--r-- | include/linux/security.h | 39 | ||||
| -rw-r--r-- | kernel/capability.c | 21 | ||||
| -rw-r--r-- | kernel/ptrace.c | 5 | ||||
| -rw-r--r-- | mm/oom_kill.c | 6 | ||||
| -rw-r--r-- | security/capability.c | 3 | ||||
| -rw-r--r-- | security/commoncap.c | 24 | ||||
| -rw-r--r-- | security/root_plug.c | 3 | ||||
| -rw-r--r-- | security/security.c | 10 | ||||
| -rw-r--r-- | security/selinux/hooks.c | 25 | ||||
| -rw-r--r-- | security/smack/smack_lsm.c | 49 |
11 files changed, 137 insertions, 63 deletions
diff --git a/include/linux/capability.h b/include/linux/capability.h index 0267384..9d1fe30 100644 --- a/include/linux/capability.h +++ b/include/linux/capability.h @@ -503,8 +503,19 @@ extern const kernel_cap_t __cap_init_eff_set; kernel_cap_t cap_set_effective(const kernel_cap_t pE_new); -int capable(int cap); -int __capable(struct task_struct *t, int cap); +/** + * has_capability - Determine if a task has a superior capability available + * @t: The task in question + * @cap: The capability to be tested for + * + * Return true if the specified task has the given superior capability + * currently in effect, false if not. + * + * Note that this does not set PF_SUPERPRIV on the task. + */ +#define has_capability(t, cap) (security_capable((t), (cap)) == 0) + +extern int capable(int cap); #endif /* __KERNEL__ */ diff --git a/include/linux/security.h b/include/linux/security.h index fd96e7f..2ee5ecf 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -46,8 +46,8 @@ struct audit_krule; */ extern int cap_capable(struct task_struct *tsk, int cap); extern int cap_settime(struct timespec *ts, struct timezone *tz); -extern int cap_ptrace(struct task_struct *parent, struct task_struct *child, - unsigned int mode); +extern int cap_ptrace_may_access(struct task_struct *child, unsigned int mode); +extern int cap_ptrace_traceme(struct task_struct *parent); extern int cap_capget(struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted); extern int cap_capset_check(struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted); extern void cap_capset_set(struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted); @@ -1157,17 +1157,24 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * @alter contains the flag indicating whether changes are to be made. * Return 0 if permission is granted. * - * @ptrace: - * Check permission before allowing the @parent process to trace the + * @ptrace_may_access: + * Check permission before allowing the current process to trace the * @child process. * Security modules may also want to perform a process tracing check * during an execve in the set_security or apply_creds hooks of * binprm_security_ops if the process is being traced and its security * attributes would be changed by the execve. - * @parent contains the task_struct structure for parent process. - * @child contains the task_struct structure for child process. + * @child contains the task_struct structure for the target process. * @mode contains the PTRACE_MODE flags indicating the form of access. * Return 0 if permission is granted. + * @ptrace_traceme: + * Check that the @parent process has sufficient permission to trace the + * current process before allowing the current process to present itself + * to the @parent process for tracing. + * The parent process will still have to undergo the ptrace_may_access + * checks before it is allowed to trace this one. + * @parent contains the task_struct structure for debugger process. + * Return 0 if permission is granted. * @capget: * Get the @effective, @inheritable, and @permitted capability sets for * the @target process. The hook may also perform permission checking to @@ -1287,8 +1294,8 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) struct security_operations { char name[SECURITY_NAME_MAX + 1]; - int (*ptrace) (struct task_struct *parent, struct task_struct *child, - unsigned int mode); + int (*ptrace_may_access) (struct task_struct *child, unsigned int mode); + int (*ptrace_traceme) (struct task_struct *parent); int (*capget) (struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted); @@ -1560,8 +1567,8 @@ extern struct dentry *securityfs_create_dir(const char *name, struct dentry *par extern void securityfs_remove(struct dentry *dentry); /* Security operations */ -int security_ptrace(struct task_struct *parent, struct task_struct *child, - unsigned int mode); +int security_ptrace_may_access(struct task_struct *child, unsigned int mode); +int security_ptrace_traceme(struct task_struct *parent); int security_capget(struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, @@ -1742,11 +1749,15 @@ static inline int security_init(void) return 0; } -static inline int security_ptrace(struct task_struct *parent, - struct task_struct *child, - unsigned int mode) +static inline int security_ptrace_may_access(struct task_struct *child, + unsigned int mode) +{ + return cap_ptrace_may_access(child, mode); +} + +static inline int security_ptrace_traceme(struct task_struct *child) { - return cap_ptrace(parent, child, mode); + return cap_ptrace_traceme(parent); } static inline int security_capget(struct task_struct *target, diff --git a/kernel/capability.c b/kernel/capability.c index 0101e84..33e51e7 100644 --- a/kernel/capability.c +++ b/kernel/capability.c @@ -486,17 +486,22 @@ asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data) return ret; } -int __capable(struct task_struct *t, int cap) +/** + * capable - Determine if the current task has a superior capability in effect + * @cap: The capability to be tested for + * + * Return true if the current task has the given superior capability currently + * available for use, false if not. + * + * This sets PF_SUPERPRIV on the task if the capability is available on the + * assumption that it's about to be used. + */ +int capable(int cap) { - if (security_capable(t, cap) == 0) { - t->flags |= PF_SUPERPRIV; + if (has_capability(current, cap)) { + current->flags |= PF_SUPERPRIV; return 1; } return 0; } - -int capable(int cap) -{ - return __capable(current, cap); -} EXPORT_SYMBOL(capable); diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 082b3fc..356699a 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -140,7 +140,7 @@ int __ptrace_may_access(struct task_struct *task, unsigned int mode) if (!dumpable && !capable(CAP_SYS_PTRACE)) return -EPERM; - return security_ptrace(current, task, mode); + return security_ptrace_may_access(task, mode); } bool ptrace_may_access(struct task_struct *task, unsigned int mode) @@ -499,8 +499,7 @@ repeat: goto repeat; } - ret = security_ptrace(current->parent, current, - PTRACE_MODE_ATTACH); + ret = security_ptrace_traceme(current->parent); /* * Set the ptrace bit in the process ptrace flags. diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 8a5467e..64e5b4b 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -26,6 +26,7 @@ #include <linux/module.h> #include <linux/notifier.h> #include <linux/memcontrol.h> +#include <linux/security.h> int sysctl_panic_on_oom; int sysctl_oom_kill_allocating_task; @@ -128,7 +129,8 @@ unsigned long badness(struct task_struct *p, unsigned long uptime) * Superuser processes are usually more important, so we make it * less likely that we kill those. */ - if (__capable(p, CAP_SYS_ADMIN) || __capable(p, CAP_SYS_RESOURCE)) + if (has_capability(p, CAP_SYS_ADMIN) || + has_capability(p, CAP_SYS_RESOURCE)) points /= 4; /* @@ -137,7 +139,7 @@ unsigned long badness(struct task_struct *p, unsigned long uptime) * tend to only have this flag set on applications they think * of as important. */ - if (__capable(p, CAP_SYS_RAWIO)) + if (has_capability(p, CAP_SYS_RAWIO)) points /= 4; /* diff --git a/security/capability.c b/security/capability.c index 63d10da..2458748 100644 --- a/security/capability.c +++ b/security/capability.c @@ -811,7 +811,8 @@ struct security_operations default_security_ops = { void security_fixup_ops(struct security_operations *ops) { - set_to_cap_if_null(ops, ptrace); + set_to_cap_if_null(ops, ptrace_may_access); + set_to_cap_if_null(ops, ptrace_traceme); set_to_cap_if_null(ops, capget); set_to_cap_if_null(ops, capset_check); set_to_cap_if_null(ops, capset_set); diff --git a/security/commoncap.c b/security/commoncap.c index 4afbece..e4c4b3f 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -63,14 +63,24 @@ int cap_settime(struct timespec *ts, struct timezone *tz) return 0; } -int cap_ptrace (struct task_struct *parent, struct task_struct *child, - unsigned int mode) +int cap_ptrace_may_access(struct task_struct *child, unsigned int mode) { /* Derived from arch/i386/kernel/ptrace.c:sys_ptrace. */ - if (!cap_issubset(child->cap_permitted, parent->cap_permitted) && - !__capable(parent, CAP_SYS_PTRACE)) - return -EPERM; - return 0; + if (cap_issubset(child->cap_permitted, current->cap_permitted)) + return 0; + if (capable(CAP_SYS_PTRACE)) + return 0; + return -EPERM; +} + +int cap_ptrace_traceme(struct task_struct *parent) +{ + /* Derived from arch/i386/kernel/ptrace.c:sys_ptrace. */ + if (cap_issubset(current->cap_permitted, parent->cap_permitted)) + return 0; + if (has_capability(parent, CAP_SYS_PTRACE)) + return 0; + return -EPERM; } int cap_capget (struct task_struct *target, kernel_cap_t *effective, @@ -534,7 +544,7 @@ int cap_task_post_setuid (uid_t old_ruid, uid_t old_euid, uid_t old_suid, static inline int cap_safe_nice(struct task_struct *p) { if (!cap_issubset(p->cap_permitted, current->cap_permitted) && - !__capable(current, CAP_SYS_NICE)) + !capable(CAP_SYS_NICE)) return -EPERM; return 0; } diff --git a/security/root_plug.c b/security/root_plug.c index be0ebec..c3f68b5 100644 --- a/security/root_plug.c +++ b/security/root_plug.c @@ -72,7 +72,8 @@ static int rootplug_bprm_check_security (struct linux_binprm *bprm) static struct security_operations rootplug_security_ops = { /* Use the capability functions for some of the hooks */ - .ptrace = cap_ptrace, + .ptrace_may_access = cap_ptrace_may_access, + .ptrace_traceme = cap_ptrace_traceme, .capget = cap_capget, .capset_check = cap_capset_check, .capset_set = cap_capset_set, diff --git a/security/security.c b/security/security.c index ff70687..3a4b4f5 100644 --- a/security/security.c +++ b/security/security.c @@ -127,10 +127,14 @@ int register_security(struct security_operations *ops) /* Security operations */ -int security_ptrace(struct task_struct *parent, struct task_struct *child, - unsigned int mode) +int security_ptrace_may_access(struct task_struct *child, unsigned int mode) { - return security_ops->ptrace(parent, child, mode); + return security_ops->ptrace_may_access(child, mode); +} + +int security_ptrace_traceme(struct task_struct *parent) +{ + return security_ops->ptrace_traceme(parent); } int security_capget(struct task_struct *target, diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 3ae9bec..03fc6a8 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -1738,24 +1738,34 @@ static inline u32 file_to_av(struct file *file) /* Hook functions begin here. */ -static int selinux_ptrace(struct task_struct *parent, - struct task_struct *child, - unsigned int mode) +static int selinux_ptrace_may_access(struct task_struct *child, + unsigned int mode) { int rc; - rc = secondary_ops->ptrace(parent, child, mode); + rc = secondary_ops->ptrace_may_access(child, mode); if (rc) return rc; if (mode == PTRACE_MODE_READ) { - struct task_security_struct *tsec = parent->security; + struct task_security_struct *tsec = current->security; struct task_security_struct *csec = child->security; return avc_has_perm(tsec->sid, csec->sid, SECCLASS_FILE, FILE__READ, NULL); } - return task_has_perm(parent, child, PROCESS__PTRACE); + return task_has_perm(current, child, PROCESS__PTRACE); +} + +static int selinux_ptrace_traceme(struct task_struct *parent) +{ + int rc; + + rc = secondary_ops->ptrace_traceme(parent); + if (rc) + return rc; + + return task_has_perm(parent, current, PROCESS__PTRACE); } static int selinux_capget(struct task_struct *target, kernel_cap_t *effective, @@ -5346,7 +5356,8 @@ static int selinux_key_getsecurity(struct key *key, char **_buffer) static struct security_operations selinux_ops = { .name = "selinux", - .ptrace = selinux_ptrace, + .ptrace_may_access = selinux_ptrace_may_access, + .ptrace_traceme = selinux_ptrace_traceme, .capget = selinux_capget, .capset_check = selinux_capset_check, .capset_set = selinux_capset_set, diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 1b40e55..87d7541 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -87,27 +87,46 @@ struct inode_smack *new_inode_smack(char *smack) */ /** - * smack_ptrace - Smack approval on ptrace - * @ptp: parent task pointer + * smack_ptrace_may_access - Smack approval on PTRACE_ATTACH * @ctp: child task pointer * * Returns 0 if access is OK, an error code otherwise * * Do the capability checks, and require read and write. */ -static int smack_ptrace(struct task_struct *ptp, struct task_struct *ctp, - unsigned int mode) +static int smack_ptrace_may_access(struct task_struct *ctp, unsigned int mode) { int rc; - rc = cap_ptrace(ptp, ctp, mode); + rc = cap_ptrace_may_access(ctp, mode); if (rc != 0) return rc; - rc = smk_access(ptp->security, ctp->security, MAY_READWRITE); - if (rc != 0 && __capable(ptp, CAP_MAC_OVERRIDE)) + rc = smk_access(current->security, ctp->security, MAY_READWRITE); + if (rc != 0 && capable(CAP_MAC_OVERRIDE)) return 0; + return rc; +} + +/** + * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME + * @ptp: parent task pointer + * + * Returns 0 if access is OK, an error code otherwise + * + * Do the capability checks, and require read and write. + */ +static int smack_ptrace_traceme(struct task_struct *ptp) +{ + int rc; + + rc = cap_ptrace_traceme(ptp); + if (rc != 0) + return rc; + rc = smk_access(ptp->security, current->security, MAY_READWRITE); + if (rc != 0 && has_capability(ptp, CAP_MAC_OVERRIDE)) + return 0; return rc; } @@ -923,7 +942,7 @@ static int smack_file_send_sigiotask(struct task_struct *tsk, */ file = container_of(fown, struct file, f_owner); rc = smk_access(file->f_security, tsk->security, MAY_WRITE); - if (rc != 0 && __capable(tsk, CAP_MAC_OVERRIDE)) + if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE)) return 0; return rc; } @@ -1164,12 +1183,12 @@ static int smack_task_wait(struct task_struct *p) * account for the smack labels having gotten to * be different in the first place. * - * This breaks the strict subjet/object access + * This breaks the strict subject/object access * control ideal, taking the object's privilege * state into account in the decision as well as * the smack value. */ - if (capable(CAP_MAC_OVERRIDE) || __capable(p, CAP_MAC_OVERRIDE)) + if (capable(CAP_MAC_OVERRIDE) || has_capability(p, CAP_MAC_OVERRIDE)) return 0; return rc; @@ -2016,9 +2035,6 @@ static int smack_setprocattr(struct task_struct *p, char *name, { char *newsmack; - if (!__capable(p, CAP_MAC_ADMIN)) - return -EPERM; - /* * Changing another process' Smack value is too dangerous * and supports no sane use case. @@ -2026,6 +2042,9 @@ static int smack_setprocattr(struct task_struct *p, char *name, if (p != current) return -EPERM; + if (!capable(CAP_MAC_ADMIN)) + return -EPERM; + if (value == NULL || size == 0 || size >= SMK_LABELLEN) return -EINVAL; @@ -2552,7 +2571,8 @@ static void smack_release_secctx(char *secdata, u32 seclen) struct security_operations smack_ops = { .name = "smack", - .ptrace = smack_ptrace, + .ptrace_may_access = smack_ptrace_may_access, + .ptrace_traceme = smack_ptrace_traceme, .capget = cap_capget, .capset_check = cap_capset_check, .capset_set = cap_capset_set, @@ -2729,4 +2749,3 @@ static __init int smack_init(void) * all processes and objects when they are created. */ security_initcall(smack_init); - |