diff options
| -rw-r--r-- | security/Kconfig | 18 | ||||
| -rw-r--r-- | security/security.c | 4 | ||||
| -rw-r--r-- | security/selinux/include/security.h | 1 | ||||
| -rw-r--r-- | security/selinux/ss/services.c | 33 |
4 files changed, 21 insertions, 35 deletions
diff --git a/security/Kconfig b/security/Kconfig index 25ffe1b9dc9..5dfc206748c 100644 --- a/security/Kconfig +++ b/security/Kconfig @@ -104,6 +104,24 @@ config SECURITY_ROOTPLUG If you are unsure how to answer this question, answer N. +config SECURITY_DEFAULT_MMAP_MIN_ADDR + int "Low address space to protect from user allocation" + depends on SECURITY + default 0 + help + This is the portion of low virtual memory which should be protected + from userspace allocation. Keeping a user from writing to low pages + can help reduce the impact of kernel NULL pointer bugs. + + For most users with lots of address space a value of 65536 is + reasonable and should cause no problems. Programs which use vm86 + functionality would either need additional permissions from either + the LSM or the capabilities module or have this protection disabled. + + This value can be changed after boot using the + /proc/sys/vm/mmap_min_addr tunable. + + source security/selinux/Kconfig source security/smack/Kconfig diff --git a/security/security.c b/security/security.c index b6c57a6b2ff..d15e56cbaad 100644 --- a/security/security.c +++ b/security/security.c @@ -23,7 +23,9 @@ extern struct security_operations dummy_security_ops; extern void security_fixup_ops(struct security_operations *ops); struct security_operations *security_ops; /* Initialized to NULL */ -unsigned long mmap_min_addr; /* 0 means no protection */ + +/* amount of vm to protect from userspace access */ +unsigned long mmap_min_addr = CONFIG_SECURITY_DEFAULT_MMAP_MIN_ADDR; static inline int verify(struct security_operations *ops) { diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h index 23137c17f91..837ce420d2f 100644 --- a/security/selinux/include/security.h +++ b/security/selinux/include/security.h @@ -107,7 +107,6 @@ int security_get_classes(char ***classes, int *nclasses); int security_get_permissions(char *class, char ***perms, int *nperms); int security_get_reject_unknown(void); int security_get_allow_unknown(void); -int security_get_policycaps(int *len, int **values); #define SECURITY_FS_USE_XATTR 1 /* use xattr */ #define SECURITY_FS_USE_TRANS 2 /* use transition SIDs, e.g. devpts/tmpfs */ diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index fced6bccee7..f3741860121 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -2246,39 +2246,6 @@ int security_get_allow_unknown(void) } /** - * security_get_policycaps - Query the loaded policy for its capabilities - * @len: the number of capability bits - * @values: the capability bit array - * - * Description: - * Get an array of the policy capabilities in @values where each entry in - * @values is either true (1) or false (0) depending the policy's support of - * that feature. The policy capabilities are defined by the - * POLICYDB_CAPABILITY_* enums. The size of the array is stored in @len and it - * is up to the caller to free the array in @values. Returns zero on success, - * negative values on failure. - * - */ -int security_get_policycaps(int *len, int **values) -{ - int rc = -ENOMEM; - unsigned int iter; - - POLICY_RDLOCK; - - *values = kcalloc(POLICYDB_CAPABILITY_MAX, sizeof(int), GFP_ATOMIC); - if (*values == NULL) - goto out; - for (iter = 0; iter < POLICYDB_CAPABILITY_MAX; iter++) - (*values)[iter] = ebitmap_get_bit(&policydb.policycaps, iter); - *len = POLICYDB_CAPABILITY_MAX; - -out: - POLICY_RDUNLOCK; - return rc; -} - -/** * security_policycap_supported - Check for a specific policy capability * @req_cap: capability * |