From 002345925e6c45861f60db6f4fc6236713fd8847 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 3 Feb 2010 15:36:43 -0800 Subject: syslog: distinguish between /proc/kmsg and syscalls This allows the LSM to distinguish between syslog functions originating from /proc/kmsg access and direct syscalls. By default, the commoncaps will now no longer require CAP_SYS_ADMIN to read an opened /proc/kmsg file descriptor. For example the kernel syslog reader can now drop privileges after opening /proc/kmsg, instead of staying privileged with CAP_SYS_ADMIN. MAC systems that implement security_syslog have unchanged behavior. Signed-off-by: Kees Cook Acked-by: Serge Hallyn Acked-by: John Johansen Signed-off-by: James Morris --- include/linux/security.h | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) (limited to 'include/linux/security.h') diff --git a/include/linux/security.h b/include/linux/security.h index 26eca85b2417..a4dc74d86ac6 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) -- cgit v1.2.3