Loading security/commoncap.c +248 −52 Original line number Diff line number Diff line Loading @@ -40,14 +40,21 @@ int cap_netlink_recv(struct sk_buff *skb, int cap) return -EPERM; return 0; } EXPORT_SYMBOL(cap_netlink_recv); /* /** * cap_capable - Determine whether a task has a particular effective capability * @tsk: The task to query * @cap: The capability to check for * @audit: Whether to write an audit message or not * * Determine whether the nominated task has the specified capability amongst * its effective set, returning 0 if it does, -ve if it does not. * * NOTE WELL: cap_capable() cannot be used like the kernel's capable() * function. That is, it has the reverse semantics: cap_capable() * returns 0 when a task has a capability, but the kernel's capable() * returns 1 for this case. * function. That is, it has the reverse semantics: cap_capable() returns 0 * when a task has a capability, but the kernel's capable() returns 1 for this * case. */ int cap_capable(struct task_struct *tsk, int cap, int audit) { Loading @@ -60,6 +67,14 @@ int cap_capable(struct task_struct *tsk, int cap, int audit) return cap_raised ? 0 : -EPERM; } /** * cap_settime - Determine whether the current process may set the system clock * @ts: The time to set * @tz: The timezone to set * * Determine whether the current process may set the system clock and timezone * information, returning 0 if permission granted, -ve if denied. */ int cap_settime(struct timespec *ts, struct timezone *tz) { if (!capable(CAP_SYS_TIME)) Loading @@ -67,6 +82,15 @@ int cap_settime(struct timespec *ts, struct timezone *tz) return 0; } /** * cap_ptrace_may_access - Determine whether the current process may access * another * @child: The process to be accessed * @mode: The mode of attachment. * * Determine whether a process may access another, returning 0 if permission * granted, -ve if denied. */ int cap_ptrace_may_access(struct task_struct *child, unsigned int mode) { int ret = 0; Loading @@ -80,6 +104,13 @@ int cap_ptrace_may_access(struct task_struct *child, unsigned int mode) return ret; } /** * cap_ptrace_traceme - Determine whether another process may trace the current * @parent: The task proposed to be the tracer * * Determine whether the nominated task is permitted to trace the current * process, returning 0 if permission is granted, -ve if denied. */ int cap_ptrace_traceme(struct task_struct *parent) { int ret = 0; Loading @@ -93,6 +124,16 @@ int cap_ptrace_traceme(struct task_struct *parent) return ret; } /** * cap_capget - Retrieve a task's capability sets * @target: The task from which to retrieve the capability sets * @effective: The place to record the effective set * @inheritable: The place to record the inheritable set * @permitted: The place to record the permitted set * * This function retrieves the capabilities of the nominated task and returns * them to the caller. */ int cap_capget(struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted) { Loading @@ -108,30 +149,35 @@ int cap_capget (struct task_struct *target, kernel_cap_t *effective, return 0; } #ifdef CONFIG_SECURITY_FILE_CAPABILITIES static inline int cap_inh_is_capped(void) { /* * Return 1 if changes to the inheritable set are limited * to the old permitted set. That is, if the current task * does *not* possess the CAP_SETPCAP capability. * Determine whether the inheritable capabilities are limited to the old * permitted set. Returns 1 if they are limited, 0 if they are not. */ return cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) != 0; } static inline int cap_limit_ptraced_target(void) { return 1; } #else /* ie., ndef CONFIG_SECURITY_FILE_CAPABILITIES */ static inline int cap_inh_is_capped(void) { return 1; } static inline int cap_limit_ptraced_target(void) static inline int cap_inh_is_capped(void) { return !capable(CAP_SETPCAP); } #ifdef CONFIG_SECURITY_FILE_CAPABILITIES #endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */ /* they are so limited unless the current task has the CAP_SETPCAP * capability */ if (cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) == 0) return 0; #endif return 1; } /** * cap_capset - Validate and apply proposed changes to current's capabilities * @new: The proposed new credentials; alterations should be made here * @old: The current task's current credentials * @effective: A pointer to the proposed new effective capabilities set * @inheritable: A pointer to the proposed new inheritable capabilities set * @permitted: A pointer to the proposed new permitted capabilities set * * This function validates and applies a proposed mass change to the current * process's capability sets. The changes are made to the proposed new * credentials, and assuming no error, will be committed by the caller of LSM. */ int cap_capset(struct cred *new, const struct cred *old, const kernel_cap_t *effective, Loading Loading @@ -165,6 +211,9 @@ int cap_capset(struct cred *new, return 0; } /* * Clear proposed capability sets for execve(). */ static inline void bprm_clear_caps(struct linux_binprm *bprm) { cap_clear(bprm->cred->cap_permitted); Loading @@ -173,6 +222,17 @@ static inline void bprm_clear_caps(struct linux_binprm *bprm) #ifdef CONFIG_SECURITY_FILE_CAPABILITIES /** * cap_inode_need_killpriv - Determine if inode change affects privileges * @dentry: The inode/dentry in being changed with change marked ATTR_KILL_PRIV * * Determine if an inode having a change applied that's marked ATTR_KILL_PRIV * affects the security markings on that inode, and if it is, should * inode_killpriv() be invoked or the change rejected? * * Returns 0 if granted; +ve if granted, but inode_killpriv() is required; and * -ve to deny the change. */ int cap_inode_need_killpriv(struct dentry *dentry) { struct inode *inode = dentry->d_inode; Loading @@ -187,6 +247,14 @@ int cap_inode_need_killpriv(struct dentry *dentry) return 1; } /** * cap_inode_killpriv - Erase the security markings on an inode * @dentry: The inode/dentry to alter * * Erase the privilege-enhancing security markings on an inode. * * Returns 0 if successful, -ve on error. */ int cap_inode_killpriv(struct dentry *dentry) { struct inode *inode = dentry->d_inode; Loading @@ -197,6 +265,10 @@ int cap_inode_killpriv(struct dentry *dentry) return inode->i_op->removexattr(dentry, XATTR_NAME_CAPS); } /* * Calculate the new process capability sets from the capability sets attached * to a file. */ static inline int bprm_caps_from_vfs_caps(struct cpu_vfs_cap_data *caps, struct linux_binprm *bprm, bool *effective) Loading Loading @@ -232,6 +304,9 @@ static inline int bprm_caps_from_vfs_caps(struct cpu_vfs_cap_data *caps, return *effective ? ret : 0; } /* * Extract the on-exec-apply capability sets for an executable file. */ int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps) { struct inode *inode = dentry->d_inode; Loading Loading @@ -283,7 +358,11 @@ int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data return 0; } /* Locate any VFS capabilities: */ /* * Attempt to get the on-exec apply capability sets for an executable file from * its xattrs and, if present, apply them to the proposed credentials being * constructed by execve(). */ static int get_file_caps(struct linux_binprm *bprm, bool *effective) { struct dentry *dentry; Loading Loading @@ -342,7 +421,31 @@ static inline int get_file_caps(struct linux_binprm *bprm, bool *effective) #endif /* * set up the new credentials for an exec'd task * Determine whether a exec'ing process's new permitted capabilities should be * limited to just what it already has. * * This prevents processes that are being ptraced from gaining access to * CAP_SETPCAP, unless the process they're tracing already has it, and the * binary they're executing has filecaps that elevate it. * * Returns 1 if they should be limited, 0 if they are not. */ static inline int cap_limit_ptraced_target(void) { #ifndef CONFIG_SECURITY_FILE_CAPABILITIES if (capable(CAP_SETPCAP)) return 0; #endif return 1; } /** * cap_bprm_set_creds - Set up the proposed credentials for execve(). * @bprm: The execution parameters, including the proposed creds * * Set up the proposed credentials for a new execution context being * constructed by execve(). The proposed creds in @bprm->cred is altered, * which won't take effect immediately. Returns 0 if successful, -ve on error. */ int cap_bprm_set_creds(struct linux_binprm *bprm) { Loading Loading @@ -430,10 +533,15 @@ int cap_bprm_set_creds(struct linux_binprm *bprm) return 0; } /* * determine whether a secure execution is required * - the creds have been committed at this point, and are no longer available * through bprm /** * cap_bprm_secureexec - Determine whether a secure execution is required * @bprm: The execution parameters * * Determine whether a secure execution is required, return 1 if it is, and 0 * if it is not. * * The credentials have been committed by this point, and so are no longer * available through @bprm->cred. */ int cap_bprm_secureexec(struct linux_binprm *bprm) { Loading @@ -450,6 +558,20 @@ int cap_bprm_secureexec(struct linux_binprm *bprm) cred->egid != cred->gid); } /** * cap_inode_setxattr - Determine whether an xattr may be altered * @dentry: The inode/dentry being altered * @name: The name of the xattr to be changed * @value: The value that the xattr will be changed to * @size: The size of value * @flags: The replacement flag * * Determine whether an xattr may be altered or set on an inode, returning 0 if * permission is granted, -ve if denied. * * This is used to make sure security xattrs don't get updated or set by those * who aren't privileged to do so. */ int cap_inode_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags) { Loading @@ -457,27 +579,41 @@ int cap_inode_setxattr(struct dentry *dentry, const char *name, if (!capable(CAP_SETFCAP)) return -EPERM; return 0; } else if (!strncmp(name, XATTR_SECURITY_PREFIX, } if (!strncmp(name, XATTR_SECURITY_PREFIX, sizeof(XATTR_SECURITY_PREFIX) - 1) && !capable(CAP_SYS_ADMIN)) return -EPERM; return 0; } /** * cap_inode_removexattr - Determine whether an xattr may be removed * @dentry: The inode/dentry being altered * @name: The name of the xattr to be changed * * Determine whether an xattr may be removed from an inode, returning 0 if * permission is granted, -ve if denied. * * This is used to make sure security xattrs don't get removed by those who * aren't privileged to remove them. */ int cap_inode_removexattr(struct dentry *dentry, const char *name) { if (!strcmp(name, XATTR_NAME_CAPS)) { if (!capable(CAP_SETFCAP)) return -EPERM; return 0; } else if (!strncmp(name, XATTR_SECURITY_PREFIX, } if (!strncmp(name, XATTR_SECURITY_PREFIX, sizeof(XATTR_SECURITY_PREFIX) - 1) && !capable(CAP_SYS_ADMIN)) return -EPERM; return 0; } /* moved from kernel/sys.c. */ /* * cap_emulate_setxuid() fixes the effective / permitted capabilities of * a process after a call to setuid, setreuid, or setresuid. Loading Loading @@ -521,35 +657,46 @@ static inline void cap_emulate_setxuid(struct cred *new, const struct cred *old) new->cap_effective = new->cap_permitted; } /** * cap_task_fix_setuid - Fix up the results of setuid() call * @new: The proposed credentials * @old: The current task's current credentials * @flags: Indications of what has changed * * Fix up the results of setuid() call before the credential changes are * actually applied, returning 0 to grant the changes, -ve to deny them. */ int cap_task_fix_setuid(struct cred *new, const struct cred *old, int flags) { switch (flags) { case LSM_SETID_RE: case LSM_SETID_ID: case LSM_SETID_RES: /* Copied from kernel/sys.c:setreuid/setuid/setresuid. */ /* juggle the capabilities to follow [RES]UID changes unless * otherwise suppressed */ if (!issecure(SECURE_NO_SETUID_FIXUP)) cap_emulate_setxuid(new, old); break; case LSM_SETID_FS: /* Copied from kernel/sys.c:setfsuid. */ /* case LSM_SETID_FS: /* juggle the capabilties to follow FSUID changes, unless * otherwise suppressed * * FIXME - is fsuser used for all CAP_FS_MASK capabilities? * if not, we might be a bit too harsh here. */ if (!issecure(SECURE_NO_SETUID_FIXUP)) { if (old->fsuid == 0 && new->fsuid != 0) { if (old->fsuid == 0 && new->fsuid != 0) new->cap_effective = cap_drop_fs_set(new->cap_effective); } if (old->fsuid != 0 && new->fsuid == 0) { if (old->fsuid != 0 && new->fsuid == 0) new->cap_effective = cap_raise_fs_set(new->cap_effective, new->cap_permitted); } } break; default: return -EINVAL; } Loading Loading @@ -582,28 +729,50 @@ static int cap_safe_nice(struct task_struct *p) return 0; } /** * cap_task_setscheduler - Detemine if scheduler policy change is permitted * @p: The task to affect * @policy: The policy to effect * @lp: The parameters to the scheduling policy * * Detemine if the requested scheduler policy change is permitted for the * specified task, returning 0 if permission is granted, -ve if denied. */ int cap_task_setscheduler(struct task_struct *p, int policy, struct sched_param *lp) { return cap_safe_nice(p); } /** * cap_task_ioprio - Detemine if I/O priority change is permitted * @p: The task to affect * @ioprio: The I/O priority to set * * Detemine if the requested I/O priority change is permitted for the specified * task, returning 0 if permission is granted, -ve if denied. */ int cap_task_setioprio(struct task_struct *p, int ioprio) { return cap_safe_nice(p); } /** * cap_task_ioprio - Detemine if task priority change is permitted * @p: The task to affect * @nice: The nice value to set * * Detemine if the requested task priority change is permitted for the * specified task, returning 0 if permission is granted, -ve if denied. */ int cap_task_setnice(struct task_struct *p, int nice) { return cap_safe_nice(p); } /* * called from kernel/sys.c for prctl(PR_CABSET_DROP) * done without task_capability_lock() because it introduces * no new races - i.e. only another task doing capget() on * this task could get inconsistent info. There can be no * racing writer bc a task can only change its own caps. * Implement PR_CAPBSET_DROP. Attempt to remove the specified capability from * the current task's bounding set. Returns 0 on success, -ve on error. */ static long cap_prctl_drop(struct cred *new, unsigned long cap) { Loading Loading @@ -632,6 +801,18 @@ int cap_task_setnice (struct task_struct *p, int nice) } #endif /** * cap_task_prctl - Implement process control functions for this security module * @option: The process control function requested * @arg2, @arg3, @arg4, @arg5: The argument data for this function * * Allow process control functions (sys_prctl()) to alter capabilities; may * also deny access to other functions not otherwise implemented here. * * Returns 0 or +ve on success, -ENOSYS if this function is not implemented * here, other -ve on error. If -ENOSYS is returned, sys_prctl() and other LSM * modules will consider performing the function. */ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, unsigned long arg5) { Loading Loading @@ -737,6 +918,13 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, return error; } /** * cap_syslog - Determine whether syslog function is permitted * @type: Function requested * * Determine whether the current process is permitted to use a particular * syslog function, returning 0 if permission is granted, -ve if not. */ int cap_syslog(int type) { if ((type != 3 && type != 10) && !capable(CAP_SYS_ADMIN)) Loading @@ -744,6 +932,14 @@ int cap_syslog (int type) return 0; } /** * cap_vm_enough_memory - Determine whether a new virtual mapping is permitted * @mm: The VM space in which the new mapping is to be made * @pages: The size of the mapping * * Determine whether the allocation of a new virtual mapping by the current * task is permitted, returning 0 if permission is granted, -ve if not. */ int cap_vm_enough_memory(struct mm_struct *mm, long pages) { int cap_sys_admin = 0; Loading Loading
security/commoncap.c +248 −52 Original line number Diff line number Diff line Loading @@ -40,14 +40,21 @@ int cap_netlink_recv(struct sk_buff *skb, int cap) return -EPERM; return 0; } EXPORT_SYMBOL(cap_netlink_recv); /* /** * cap_capable - Determine whether a task has a particular effective capability * @tsk: The task to query * @cap: The capability to check for * @audit: Whether to write an audit message or not * * Determine whether the nominated task has the specified capability amongst * its effective set, returning 0 if it does, -ve if it does not. * * NOTE WELL: cap_capable() cannot be used like the kernel's capable() * function. That is, it has the reverse semantics: cap_capable() * returns 0 when a task has a capability, but the kernel's capable() * returns 1 for this case. * function. That is, it has the reverse semantics: cap_capable() returns 0 * when a task has a capability, but the kernel's capable() returns 1 for this * case. */ int cap_capable(struct task_struct *tsk, int cap, int audit) { Loading @@ -60,6 +67,14 @@ int cap_capable(struct task_struct *tsk, int cap, int audit) return cap_raised ? 0 : -EPERM; } /** * cap_settime - Determine whether the current process may set the system clock * @ts: The time to set * @tz: The timezone to set * * Determine whether the current process may set the system clock and timezone * information, returning 0 if permission granted, -ve if denied. */ int cap_settime(struct timespec *ts, struct timezone *tz) { if (!capable(CAP_SYS_TIME)) Loading @@ -67,6 +82,15 @@ int cap_settime(struct timespec *ts, struct timezone *tz) return 0; } /** * cap_ptrace_may_access - Determine whether the current process may access * another * @child: The process to be accessed * @mode: The mode of attachment. * * Determine whether a process may access another, returning 0 if permission * granted, -ve if denied. */ int cap_ptrace_may_access(struct task_struct *child, unsigned int mode) { int ret = 0; Loading @@ -80,6 +104,13 @@ int cap_ptrace_may_access(struct task_struct *child, unsigned int mode) return ret; } /** * cap_ptrace_traceme - Determine whether another process may trace the current * @parent: The task proposed to be the tracer * * Determine whether the nominated task is permitted to trace the current * process, returning 0 if permission is granted, -ve if denied. */ int cap_ptrace_traceme(struct task_struct *parent) { int ret = 0; Loading @@ -93,6 +124,16 @@ int cap_ptrace_traceme(struct task_struct *parent) return ret; } /** * cap_capget - Retrieve a task's capability sets * @target: The task from which to retrieve the capability sets * @effective: The place to record the effective set * @inheritable: The place to record the inheritable set * @permitted: The place to record the permitted set * * This function retrieves the capabilities of the nominated task and returns * them to the caller. */ int cap_capget(struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted) { Loading @@ -108,30 +149,35 @@ int cap_capget (struct task_struct *target, kernel_cap_t *effective, return 0; } #ifdef CONFIG_SECURITY_FILE_CAPABILITIES static inline int cap_inh_is_capped(void) { /* * Return 1 if changes to the inheritable set are limited * to the old permitted set. That is, if the current task * does *not* possess the CAP_SETPCAP capability. * Determine whether the inheritable capabilities are limited to the old * permitted set. Returns 1 if they are limited, 0 if they are not. */ return cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) != 0; } static inline int cap_limit_ptraced_target(void) { return 1; } #else /* ie., ndef CONFIG_SECURITY_FILE_CAPABILITIES */ static inline int cap_inh_is_capped(void) { return 1; } static inline int cap_limit_ptraced_target(void) static inline int cap_inh_is_capped(void) { return !capable(CAP_SETPCAP); } #ifdef CONFIG_SECURITY_FILE_CAPABILITIES #endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */ /* they are so limited unless the current task has the CAP_SETPCAP * capability */ if (cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) == 0) return 0; #endif return 1; } /** * cap_capset - Validate and apply proposed changes to current's capabilities * @new: The proposed new credentials; alterations should be made here * @old: The current task's current credentials * @effective: A pointer to the proposed new effective capabilities set * @inheritable: A pointer to the proposed new inheritable capabilities set * @permitted: A pointer to the proposed new permitted capabilities set * * This function validates and applies a proposed mass change to the current * process's capability sets. The changes are made to the proposed new * credentials, and assuming no error, will be committed by the caller of LSM. */ int cap_capset(struct cred *new, const struct cred *old, const kernel_cap_t *effective, Loading Loading @@ -165,6 +211,9 @@ int cap_capset(struct cred *new, return 0; } /* * Clear proposed capability sets for execve(). */ static inline void bprm_clear_caps(struct linux_binprm *bprm) { cap_clear(bprm->cred->cap_permitted); Loading @@ -173,6 +222,17 @@ static inline void bprm_clear_caps(struct linux_binprm *bprm) #ifdef CONFIG_SECURITY_FILE_CAPABILITIES /** * cap_inode_need_killpriv - Determine if inode change affects privileges * @dentry: The inode/dentry in being changed with change marked ATTR_KILL_PRIV * * Determine if an inode having a change applied that's marked ATTR_KILL_PRIV * affects the security markings on that inode, and if it is, should * inode_killpriv() be invoked or the change rejected? * * Returns 0 if granted; +ve if granted, but inode_killpriv() is required; and * -ve to deny the change. */ int cap_inode_need_killpriv(struct dentry *dentry) { struct inode *inode = dentry->d_inode; Loading @@ -187,6 +247,14 @@ int cap_inode_need_killpriv(struct dentry *dentry) return 1; } /** * cap_inode_killpriv - Erase the security markings on an inode * @dentry: The inode/dentry to alter * * Erase the privilege-enhancing security markings on an inode. * * Returns 0 if successful, -ve on error. */ int cap_inode_killpriv(struct dentry *dentry) { struct inode *inode = dentry->d_inode; Loading @@ -197,6 +265,10 @@ int cap_inode_killpriv(struct dentry *dentry) return inode->i_op->removexattr(dentry, XATTR_NAME_CAPS); } /* * Calculate the new process capability sets from the capability sets attached * to a file. */ static inline int bprm_caps_from_vfs_caps(struct cpu_vfs_cap_data *caps, struct linux_binprm *bprm, bool *effective) Loading Loading @@ -232,6 +304,9 @@ static inline int bprm_caps_from_vfs_caps(struct cpu_vfs_cap_data *caps, return *effective ? ret : 0; } /* * Extract the on-exec-apply capability sets for an executable file. */ int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps) { struct inode *inode = dentry->d_inode; Loading Loading @@ -283,7 +358,11 @@ int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data return 0; } /* Locate any VFS capabilities: */ /* * Attempt to get the on-exec apply capability sets for an executable file from * its xattrs and, if present, apply them to the proposed credentials being * constructed by execve(). */ static int get_file_caps(struct linux_binprm *bprm, bool *effective) { struct dentry *dentry; Loading Loading @@ -342,7 +421,31 @@ static inline int get_file_caps(struct linux_binprm *bprm, bool *effective) #endif /* * set up the new credentials for an exec'd task * Determine whether a exec'ing process's new permitted capabilities should be * limited to just what it already has. * * This prevents processes that are being ptraced from gaining access to * CAP_SETPCAP, unless the process they're tracing already has it, and the * binary they're executing has filecaps that elevate it. * * Returns 1 if they should be limited, 0 if they are not. */ static inline int cap_limit_ptraced_target(void) { #ifndef CONFIG_SECURITY_FILE_CAPABILITIES if (capable(CAP_SETPCAP)) return 0; #endif return 1; } /** * cap_bprm_set_creds - Set up the proposed credentials for execve(). * @bprm: The execution parameters, including the proposed creds * * Set up the proposed credentials for a new execution context being * constructed by execve(). The proposed creds in @bprm->cred is altered, * which won't take effect immediately. Returns 0 if successful, -ve on error. */ int cap_bprm_set_creds(struct linux_binprm *bprm) { Loading Loading @@ -430,10 +533,15 @@ int cap_bprm_set_creds(struct linux_binprm *bprm) return 0; } /* * determine whether a secure execution is required * - the creds have been committed at this point, and are no longer available * through bprm /** * cap_bprm_secureexec - Determine whether a secure execution is required * @bprm: The execution parameters * * Determine whether a secure execution is required, return 1 if it is, and 0 * if it is not. * * The credentials have been committed by this point, and so are no longer * available through @bprm->cred. */ int cap_bprm_secureexec(struct linux_binprm *bprm) { Loading @@ -450,6 +558,20 @@ int cap_bprm_secureexec(struct linux_binprm *bprm) cred->egid != cred->gid); } /** * cap_inode_setxattr - Determine whether an xattr may be altered * @dentry: The inode/dentry being altered * @name: The name of the xattr to be changed * @value: The value that the xattr will be changed to * @size: The size of value * @flags: The replacement flag * * Determine whether an xattr may be altered or set on an inode, returning 0 if * permission is granted, -ve if denied. * * This is used to make sure security xattrs don't get updated or set by those * who aren't privileged to do so. */ int cap_inode_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags) { Loading @@ -457,27 +579,41 @@ int cap_inode_setxattr(struct dentry *dentry, const char *name, if (!capable(CAP_SETFCAP)) return -EPERM; return 0; } else if (!strncmp(name, XATTR_SECURITY_PREFIX, } if (!strncmp(name, XATTR_SECURITY_PREFIX, sizeof(XATTR_SECURITY_PREFIX) - 1) && !capable(CAP_SYS_ADMIN)) return -EPERM; return 0; } /** * cap_inode_removexattr - Determine whether an xattr may be removed * @dentry: The inode/dentry being altered * @name: The name of the xattr to be changed * * Determine whether an xattr may be removed from an inode, returning 0 if * permission is granted, -ve if denied. * * This is used to make sure security xattrs don't get removed by those who * aren't privileged to remove them. */ int cap_inode_removexattr(struct dentry *dentry, const char *name) { if (!strcmp(name, XATTR_NAME_CAPS)) { if (!capable(CAP_SETFCAP)) return -EPERM; return 0; } else if (!strncmp(name, XATTR_SECURITY_PREFIX, } if (!strncmp(name, XATTR_SECURITY_PREFIX, sizeof(XATTR_SECURITY_PREFIX) - 1) && !capable(CAP_SYS_ADMIN)) return -EPERM; return 0; } /* moved from kernel/sys.c. */ /* * cap_emulate_setxuid() fixes the effective / permitted capabilities of * a process after a call to setuid, setreuid, or setresuid. Loading Loading @@ -521,35 +657,46 @@ static inline void cap_emulate_setxuid(struct cred *new, const struct cred *old) new->cap_effective = new->cap_permitted; } /** * cap_task_fix_setuid - Fix up the results of setuid() call * @new: The proposed credentials * @old: The current task's current credentials * @flags: Indications of what has changed * * Fix up the results of setuid() call before the credential changes are * actually applied, returning 0 to grant the changes, -ve to deny them. */ int cap_task_fix_setuid(struct cred *new, const struct cred *old, int flags) { switch (flags) { case LSM_SETID_RE: case LSM_SETID_ID: case LSM_SETID_RES: /* Copied from kernel/sys.c:setreuid/setuid/setresuid. */ /* juggle the capabilities to follow [RES]UID changes unless * otherwise suppressed */ if (!issecure(SECURE_NO_SETUID_FIXUP)) cap_emulate_setxuid(new, old); break; case LSM_SETID_FS: /* Copied from kernel/sys.c:setfsuid. */ /* case LSM_SETID_FS: /* juggle the capabilties to follow FSUID changes, unless * otherwise suppressed * * FIXME - is fsuser used for all CAP_FS_MASK capabilities? * if not, we might be a bit too harsh here. */ if (!issecure(SECURE_NO_SETUID_FIXUP)) { if (old->fsuid == 0 && new->fsuid != 0) { if (old->fsuid == 0 && new->fsuid != 0) new->cap_effective = cap_drop_fs_set(new->cap_effective); } if (old->fsuid != 0 && new->fsuid == 0) { if (old->fsuid != 0 && new->fsuid == 0) new->cap_effective = cap_raise_fs_set(new->cap_effective, new->cap_permitted); } } break; default: return -EINVAL; } Loading Loading @@ -582,28 +729,50 @@ static int cap_safe_nice(struct task_struct *p) return 0; } /** * cap_task_setscheduler - Detemine if scheduler policy change is permitted * @p: The task to affect * @policy: The policy to effect * @lp: The parameters to the scheduling policy * * Detemine if the requested scheduler policy change is permitted for the * specified task, returning 0 if permission is granted, -ve if denied. */ int cap_task_setscheduler(struct task_struct *p, int policy, struct sched_param *lp) { return cap_safe_nice(p); } /** * cap_task_ioprio - Detemine if I/O priority change is permitted * @p: The task to affect * @ioprio: The I/O priority to set * * Detemine if the requested I/O priority change is permitted for the specified * task, returning 0 if permission is granted, -ve if denied. */ int cap_task_setioprio(struct task_struct *p, int ioprio) { return cap_safe_nice(p); } /** * cap_task_ioprio - Detemine if task priority change is permitted * @p: The task to affect * @nice: The nice value to set * * Detemine if the requested task priority change is permitted for the * specified task, returning 0 if permission is granted, -ve if denied. */ int cap_task_setnice(struct task_struct *p, int nice) { return cap_safe_nice(p); } /* * called from kernel/sys.c for prctl(PR_CABSET_DROP) * done without task_capability_lock() because it introduces * no new races - i.e. only another task doing capget() on * this task could get inconsistent info. There can be no * racing writer bc a task can only change its own caps. * Implement PR_CAPBSET_DROP. Attempt to remove the specified capability from * the current task's bounding set. Returns 0 on success, -ve on error. */ static long cap_prctl_drop(struct cred *new, unsigned long cap) { Loading Loading @@ -632,6 +801,18 @@ int cap_task_setnice (struct task_struct *p, int nice) } #endif /** * cap_task_prctl - Implement process control functions for this security module * @option: The process control function requested * @arg2, @arg3, @arg4, @arg5: The argument data for this function * * Allow process control functions (sys_prctl()) to alter capabilities; may * also deny access to other functions not otherwise implemented here. * * Returns 0 or +ve on success, -ENOSYS if this function is not implemented * here, other -ve on error. If -ENOSYS is returned, sys_prctl() and other LSM * modules will consider performing the function. */ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, unsigned long arg5) { Loading Loading @@ -737,6 +918,13 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, return error; } /** * cap_syslog - Determine whether syslog function is permitted * @type: Function requested * * Determine whether the current process is permitted to use a particular * syslog function, returning 0 if permission is granted, -ve if not. */ int cap_syslog(int type) { if ((type != 3 && type != 10) && !capable(CAP_SYS_ADMIN)) Loading @@ -744,6 +932,14 @@ int cap_syslog (int type) return 0; } /** * cap_vm_enough_memory - Determine whether a new virtual mapping is permitted * @mm: The VM space in which the new mapping is to be made * @pages: The size of the mapping * * Determine whether the allocation of a new virtual mapping by the current * task is permitted, returning 0 if permission is granted, -ve if not. */ int cap_vm_enough_memory(struct mm_struct *mm, long pages) { int cap_sys_admin = 0; Loading