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. If anyone has any objections to this change, please let me know. include/linux/security.h | 17 +++++++++++++++++ kernel/sysctl.c | 5 +++++ security/dummy.c | 6 ++++++ 3 files changed, 28 insertions(+) ----- ===== include/linux/security.h 1.9 vs edited ===== --- 1.9/include/linux/security.h Wed Dec 18 09:10:50 2002 +++ edited/include/linux/security.h Fri Jan 17 14:49:12 2003 @@ -771,6 +771,12 @@ * 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. @@ -802,6 +808,7 @@ 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); @@ -992,6 +999,11 @@ 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) { @@ -1593,6 +1605,11 @@ } static inline int security_acct (struct file *file) +{ + return 0; +} + +static inline int security_sysctl(ctl_table * table, int op) { return 0; } ===== kernel/sysctl.c 1.37 vs edited ===== --- 1.37/kernel/sysctl.c Thu Dec 5 11:06:54 2002 +++ edited/kernel/sysctl.c Fri Jan 17 14:49:15 2003 @@ -33,6 +33,7 @@ #include <linux/highuid.h> #include <linux/writeback.h> #include <linux/hugetlb.h> +#include <linux/security.h> #include <asm/uaccess.h> #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); } ===== security/dummy.c 1.14 vs edited ===== --- 1.14/security/dummy.c Wed Dec 18 09:11:56 2002 +++ edited/security/dummy.c Fri Jan 17 14:49:15 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; @@ -628,6 +633,7 @@ 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); -- Stephen Smalley, NSA sdsat_private _______________________________________________ linux-security-module mailing list linux-security-moduleat_private http://mail.wirex.com/mailman/listinfo/linux-security-module
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