diff options
| -rw-r--r-- | fs/proc/kmsg.c | 14 | ||||
| -rw-r--r-- | include/linux/security.h | 11 | ||||
| -rw-r--r-- | include/linux/syslog.h | 29 | ||||
| -rw-r--r-- | kernel/printk.c | 7 | ||||
| -rw-r--r-- | security/commoncap.c | 7 | ||||
| -rw-r--r-- | security/security.c | 4 | ||||
| -rw-r--r-- | security/selinux/hooks.c | 5 | ||||
| -rw-r--r-- | security/smack/smack_lsm.c | 4 |
8 files changed, 59 insertions, 22 deletions
diff --git a/fs/proc/kmsg.c b/fs/proc/kmsg.c index 7ca7834..6a3d843 100644 --- a/fs/proc/kmsg.c +++ b/fs/proc/kmsg.c @@ -12,37 +12,37 @@ #include <linux/poll.h> #include <linux/proc_fs.h> #include <linux/fs.h> +#include <linux/syslog.h> #include <asm/uaccess.h> #include <asm/io.h> extern wait_queue_head_t log_wait; -extern int do_syslog(int type, char __user *bug, int count); - static int kmsg_open(struct inode * inode, struct file * file) { - return do_syslog(1,NULL,0); + return do_syslog(1, NULL, 0, SYSLOG_FROM_FILE); } static int kmsg_release(struct inode * inode, struct file * file) { - (void) do_syslog(0,NULL,0); + (void) do_syslog(0, NULL, 0, SYSLOG_FROM_FILE); return 0; } static ssize_t kmsg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { - if ((file->f_flags & O_NONBLOCK) && !do_syslog(9, NULL, 0)) + if ((file->f_flags & O_NONBLOCK) && + !do_syslog(9, NULL, 0, SYSLOG_FROM_FILE)) return -EAGAIN; - return do_syslog(2, buf, count); + return do_syslog(2, buf, count, SYSLOG_FROM_FILE); } static unsigned int kmsg_poll(struct file *file, poll_table *wait) { poll_wait(file, &log_wait, wait); - if (do_syslog(9, NULL, 0)) + if (do_syslog(9, NULL, 0, SYSLOG_FROM_FILE)) return POLLIN | POLLRDNORM; return 0; } diff --git a/include/linux/security.h b/include/linux/security.h index 26eca85..a4dc74d 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -76,7 +76,7 @@ extern int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, extern int cap_task_setscheduler(struct task_struct *p, int policy, struct sched_param *lp); extern int cap_task_setioprio(struct task_struct *p, int ioprio); extern int cap_task_setnice(struct task_struct *p, int nice); -extern int cap_syslog(int type); +extern int cap_syslog(int type, bool from_file); extern int cap_vm_enough_memory(struct mm_struct *mm, long pages); struct msghdr; @@ -1349,6 +1349,7 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * logging to the console. * See the syslog(2) manual page for an explanation of the @type values. * @type contains the type of action. + * @from_file indicates the context of action (if it came from /proc). * Return 0 if permission is granted. * @settime: * Check permission to change the system time. @@ -1463,7 +1464,7 @@ struct security_operations { 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); + int (*syslog) (int type, bool from_file); int (*settime) (struct timespec *ts, struct timezone *tz); int (*vm_enough_memory) (struct mm_struct *mm, long pages); @@ -1762,7 +1763,7 @@ int security_acct(struct file *file); 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); +int security_syslog(int type, bool from_file); int security_settime(struct timespec *ts, struct timezone *tz); int security_vm_enough_memory(long pages); int security_vm_enough_memory_mm(struct mm_struct *mm, long pages); @@ -2008,9 +2009,9 @@ static inline int security_quota_on(struct dentry *dentry) return 0; } -static inline int security_syslog(int type) +static inline int security_syslog(int type, bool from_file) { - return cap_syslog(type); + return cap_syslog(type, from_file); } static inline int security_settime(struct timespec *ts, struct timezone *tz) diff --git a/include/linux/syslog.h b/include/linux/syslog.h new file mode 100644 index 0000000..5f02b18 --- /dev/null +++ b/include/linux/syslog.h @@ -0,0 +1,29 @@ +/* Syslog internals + * + * Copyright 2010 Canonical, Ltd. + * Author: Kees Cook <kees.cook@canonical.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2, or (at your option) + * any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; see the file COPYING. If not, write to + * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#ifndef _LINUX_SYSLOG_H +#define _LINUX_SYSLOG_H + +#define SYSLOG_FROM_CALL 0 +#define SYSLOG_FROM_FILE 1 + +int do_syslog(int type, char __user *buf, int count, bool from_file); + +#endif /* _LINUX_SYSLOG_H */ diff --git a/kernel/printk.c b/kernel/printk.c index 17463ca..809cf9a 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -35,6 +35,7 @@ #include <linux/kexec.h> #include <linux/ratelimit.h> #include <linux/kmsg_dump.h> +#include <linux/syslog.h> #include <asm/uaccess.h> @@ -273,14 +274,14 @@ static inline void boot_delay_msec(void) * 9 -- Return number of unread characters in the log buffer * 10 -- Return size of the log buffer */ -int do_syslog(int type, char __user *buf, int len) +int do_syslog(int type, char __user *buf, int len, bool from_file) { unsigned i, j, limit, count; int do_clear = 0; char c; int error = 0; - error = security_syslog(type); + error = security_syslog(type, from_file); if (error) return error; @@ -417,7 +418,7 @@ out: SYSCALL_DEFINE3(syslog, int, type, char __user *, buf, int, len) { - return do_syslog(type, buf, len); + return do_syslog(type, buf, len, SYSLOG_FROM_CALL); } /* diff --git a/security/commoncap.c b/security/commoncap.c index f800fdb..677fad9 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -27,6 +27,7 @@ #include <linux/sched.h> #include <linux/prctl.h> #include <linux/securebits.h> +#include <linux/syslog.h> /* * If a non-root user executes a setuid-root binary in @@ -888,12 +889,16 @@ error: /** * cap_syslog - Determine whether syslog function is permitted * @type: Function requested + * @from_file: Whether this request came from an open file (i.e. /proc) * * 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) +int cap_syslog(int type, bool from_file) { + /* /proc/kmsg can open be opened by CAP_SYS_ADMIN */ + if (type != 1 && from_file) + return 0; if ((type != 3 && type != 10) && !capable(CAP_SYS_ADMIN)) return -EPERM; return 0; diff --git a/security/security.c b/security/security.c index 440afe5..971092c 100644 --- a/security/security.c +++ b/security/security.c @@ -203,9 +203,9 @@ int security_quota_on(struct dentry *dentry) return security_ops->quota_on(dentry); } -int security_syslog(int type) +int security_syslog(int type, bool from_file) { - return security_ops->syslog(type); + return security_ops->syslog(type, from_file); } int security_settime(struct timespec *ts, struct timezone *tz) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 9a2ee84..a4862a0 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -76,6 +76,7 @@ #include <linux/selinux.h> #include <linux/mutex.h> #include <linux/posix-timers.h> +#include <linux/syslog.h> #include "avc.h" #include "objsec.h" @@ -2049,11 +2050,11 @@ static int selinux_quota_on(struct dentry *dentry) return dentry_has_perm(cred, NULL, dentry, FILE__QUOTAON); } -static int selinux_syslog(int type) +static int selinux_syslog(int type, bool from_file) { int rc; - rc = cap_syslog(type); + rc = cap_syslog(type, from_file); if (rc) return rc; diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 529c9ca..a5721b3 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -157,12 +157,12 @@ static int smack_ptrace_traceme(struct task_struct *ptp) * * Returns 0 on success, error code otherwise. */ -static int smack_syslog(int type) +static int smack_syslog(int type, bool from_file) { int rc; char *sp = current_security(); - rc = cap_syslog(type); + rc = cap_syslog(type, from_file); if (rc != 0) return rc; |