Commit dd8dbf2e authored by Eric Paris's avatar Eric Paris Committed by James Morris

security: report the module name to security_module_request

For SELinux to do better filtering in userspace we send the name of the
module along with the AVC denial when a program is denied module_request.

Example output:

type=SYSCALL msg=audit(11/03/2009 10:59:43.510:9) : arch=x86_64 syscall=write success=yes exit=2 a0=3 a1=7fc28c0d56c0 a2=2 a3=7fffca0d7440 items=0 ppid=1727 pid=1729 auid=unset uid=root gid=root euid=root suid=root fsuid=root egid=root sgid=root fsgid=root tty=(none) ses=unset comm=rpc.nfsd exe=/usr/sbin/rpc.nfsd subj=system_u:system_r:nfsd_t:s0 key=(null)
type=AVC msg=audit(11/03/2009 10:59:43.510:9) : avc:  denied  { module_request } for  pid=1729 comm=rpc.nfsd kmod="net-pf-10" scontext=system_u:system_r:nfsd_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=system
Signed-off-by: default avatarEric Paris <eparis@redhat.com>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
parent 6e65f92f
......@@ -26,14 +26,15 @@
/* Auxiliary data to use in generating the audit record. */
struct common_audit_data {
char type;
#define LSM_AUDIT_DATA_FS 1
#define LSM_AUDIT_DATA_NET 2
#define LSM_AUDIT_DATA_CAP 3
#define LSM_AUDIT_DATA_IPC 4
#define LSM_AUDIT_DATA_TASK 5
#define LSM_AUDIT_DATA_KEY 6
#define LSM_AUDIT_NO_AUDIT 7
char type;
#define LSM_AUDIT_DATA_FS 1
#define LSM_AUDIT_DATA_NET 2
#define LSM_AUDIT_DATA_CAP 3
#define LSM_AUDIT_DATA_IPC 4
#define LSM_AUDIT_DATA_TASK 5
#define LSM_AUDIT_DATA_KEY 6
#define LSM_AUDIT_NO_AUDIT 7
#define LSM_AUDIT_DATA_KMOD 8
struct task_struct *tsk;
union {
struct {
......@@ -66,6 +67,7 @@ struct common_audit_data {
char *key_desc;
} key_struct;
#endif
char *kmod_name;
} u;
/* this union contains LSM specific data */
union {
......
......@@ -706,6 +706,7 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
* @kernel_module_request:
* Ability to trigger the kernel to automatically upcall to userspace for
* userspace to load a kernel module with the given name.
* @kmod_name name of the module requested by the kernel
* Return 0 if successful.
* @task_setuid:
* Check permission before setting one or more of the user identity
......@@ -1577,7 +1578,7 @@ struct security_operations {
void (*cred_transfer)(struct cred *new, const struct cred *old);
int (*kernel_act_as)(struct cred *new, u32 secid);
int (*kernel_create_files_as)(struct cred *new, struct inode *inode);
int (*kernel_module_request)(void);
int (*kernel_module_request)(char *kmod_name);
int (*task_setuid) (uid_t id0, uid_t id1, uid_t id2, int flags);
int (*task_fix_setuid) (struct cred *new, const struct cred *old,
int flags);
......@@ -1842,7 +1843,7 @@ void security_commit_creds(struct cred *new, const struct cred *old);
void security_transfer_creds(struct cred *new, const struct cred *old);
int security_kernel_act_as(struct cred *new, u32 secid);
int security_kernel_create_files_as(struct cred *new, struct inode *inode);
int security_kernel_module_request(void);
int security_kernel_module_request(char *kmod_name);
int security_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags);
int security_task_fix_setuid(struct cred *new, const struct cred *old,
int flags);
......@@ -2407,7 +2408,7 @@ static inline int security_kernel_create_files_as(struct cred *cred,
return 0;
}
static inline int security_kernel_module_request(void)
static inline int security_kernel_module_request(char *kmod_name)
{
return 0;
}
......
......@@ -80,16 +80,16 @@ int __request_module(bool wait, const char *fmt, ...)
#define MAX_KMOD_CONCURRENT 50 /* Completely arbitrary value - KAO */
static int kmod_loop_msg;
ret = security_kernel_module_request();
if (ret)
return ret;
va_start(args, fmt);
ret = vsnprintf(module_name, MODULE_NAME_LEN, fmt, args);
va_end(args);
if (ret >= MODULE_NAME_LEN)
return -ENAMETOOLONG;
ret = security_kernel_module_request(module_name);
if (ret)
return ret;
/* If modprobe needs a service that is in a module, we get a recursive
* loop. Limit the number of running kmod threads to max_threads/2 or
* MAX_KMOD_CONCURRENT, whichever is the smaller. A cleaner method
......
......@@ -421,7 +421,7 @@ static int cap_kernel_create_files_as(struct cred *new, struct inode *inode)
return 0;
}
static int cap_kernel_module_request(void)
static int cap_kernel_module_request(char *kmod_name)
{
return 0;
}
......
......@@ -354,6 +354,10 @@ static void dump_common_audit_data(struct audit_buffer *ab,
}
break;
#endif
case LSM_AUDIT_DATA_KMOD:
audit_log_format(ab, " kmod=");
audit_log_untrustedstring(ab, a->u.kmod_name);
break;
} /* switch (a->type) */
}
......
......@@ -764,9 +764,9 @@ int security_kernel_create_files_as(struct cred *new, struct inode *inode)
return security_ops->kernel_create_files_as(new, inode);
}
int security_kernel_module_request(void)
int security_kernel_module_request(char *kmod_name)
{
return security_ops->kernel_module_request();
return security_ops->kernel_module_request(kmod_name);
}
int security_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags)
......
......@@ -3337,9 +3337,18 @@ static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
return 0;
}
static int selinux_kernel_module_request(void)
static int selinux_kernel_module_request(char *kmod_name)
{
return task_has_system(current, SYSTEM__MODULE_REQUEST);
u32 sid;
struct common_audit_data ad;
sid = task_sid(current);
COMMON_AUDIT_DATA_INIT(&ad, KMOD);
ad.u.kmod_name = kmod_name;
return avc_has_perm(sid, SECINITSID_KERNEL, SECCLASS_SYSTEM,
SYSTEM__MODULE_REQUEST, &ad);
}
static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
......
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