ChangeSet 1.983, 2003/02/05 14:32:08+11:00, sds@epoch.ncsc.mil [PATCH] LSM: Add LSM sysctl hook to 2.5.59 This patch adds a LSM sysctl hook for controlling access to sysctl variables to 2.5.59, split out from the lsm-2.5 BitKeeper tree. SELinux uses this hook to control such accesses in accordance with the security policy configuration. diff -Nru a/include/linux/security.h b/include/linux/security.h --- a/include/linux/security.h Wed Feb 5 14:58:19 2003 +++ b/include/linux/security.h Wed Feb 5 14:58:19 2003 @@ -767,6 +767,12 @@ * is NULL. * @file contains the file structure for the accounting file (may be NULL). * Return 0 if permission is granted. + * @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. * @capable: * Check whether the @tsk process has the @cap capability. * @tsk contains the task_struct for the process. @@ -798,6 +804,7 @@ kernel_cap_t * inheritable, kernel_cap_t * permitted); int (*acct) (struct file * file); + int (*sysctl) (ctl_table * table, int op); int (*capable) (struct task_struct * tsk, int cap); int (*quotactl) (int cmds, int type, int id, struct super_block * sb); int (*quota_on) (struct file * f); @@ -990,6 +997,11 @@ return security_ops->acct (file); } +static inline int security_sysctl(ctl_table * table, int op) +{ + return security_ops->sysctl(table, op); +} + static inline int security_quotactl (int cmds, int type, int id, struct super_block *sb) { @@ -1595,6 +1607,11 @@ } static inline int security_acct (struct file *file) +{ + return 0; +} + +static inline int security_sysctl(ctl_table * table, int op) { return 0; } diff -Nru a/kernel/sysctl.c b/kernel/sysctl.c --- a/kernel/sysctl.c Wed Feb 5 14:58:19 2003 +++ b/kernel/sysctl.c Wed Feb 5 14:58:19 2003 @@ -33,6 +33,7 @@ #include #include #include +#include #include #ifdef CONFIG_ROOT_NFS @@ -432,6 +433,10 @@ static inline int ctl_perm(ctl_table *table, int op) { + int error; + error = security_sysctl(table, op); + if (error) + return error; return test_perm(table->mode, op); } diff -Nru a/security/dummy.c b/security/dummy.c --- a/security/dummy.c Wed Feb 5 14:58:19 2003 +++ b/security/dummy.c Wed Feb 5 14:58:19 2003 @@ -75,6 +75,11 @@ return -EPERM; } +static int dummy_sysctl (ctl_table * table, int op) +{ + return 0; +} + static int dummy_quotactl (int cmds, int type, int id, struct super_block *sb) { return 0; @@ -634,6 +639,7 @@ set_to_dummy_if_null(ops, capable); set_to_dummy_if_null(ops, quotactl); set_to_dummy_if_null(ops, quota_on); + set_to_dummy_if_null(ops, sysctl); set_to_dummy_if_null(ops, bprm_alloc_security); set_to_dummy_if_null(ops, bprm_free_security); set_to_dummy_if_null(ops, bprm_compute_creds);