AUDIT: Avoid sleeping function in SElinux AVC audit.

This patch changes the SELinux AVC to defer logging of paths to the audit
framework upon syscall exit, by saving a reference to the (dentry,vfsmount)
pair in an auxiliary audit item on the current audit context for processing
by audit_log_exit.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
This commit is contained in:
Stephen Smalley 2005-05-21 00:15:52 +01:00 committed by David Woodhouse
parent fb19b4c6aa
commit 011161051b
3 changed files with 51 additions and 9 deletions

View file

@ -69,6 +69,7 @@
#define AUDIT_AVC 1400 /* SE Linux avc denial or grant */
#define AUDIT_SELINUX_ERR 1401 /* Internal SE Linux Errors */
#define AUDIT_AVC_PATH 1402 /* dentry, vfsmount pair from avc */
#define AUDIT_KERNEL 2000 /* Asynchronous audit record. NOT A REQUEST. */
@ -225,6 +226,7 @@ extern uid_t audit_get_loginuid(struct audit_context *ctx);
extern int audit_ipc_perms(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mode);
extern int audit_socketcall(int nargs, unsigned long *args);
extern int audit_sockaddr(int len, void *addr);
extern int audit_avc_path(struct dentry *dentry, struct vfsmount *mnt);
extern void audit_signal_info(int sig, struct task_struct *t);
#else
#define audit_alloc(t) ({ 0; })
@ -240,6 +242,7 @@ extern void audit_signal_info(int sig, struct task_struct *t);
#define audit_ipc_perms(q,u,g,m) ({ 0; })
#define audit_socketcall(n,a) ({ 0; })
#define audit_sockaddr(len, addr) ({ 0; })
#define audit_avc_path(dentry, mnt) ({ 0; })
#define audit_signal_info(s,t) do { ; } while (0)
#endif

View file

@ -34,6 +34,7 @@
#include <asm/types.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/mount.h>
#include <linux/socket.h>
#include <linux/audit.h>
#include <linux/personality.h>
@ -124,6 +125,11 @@ struct audit_aux_data_sockaddr {
char a[0];
};
struct audit_aux_data_path {
struct audit_aux_data d;
struct dentry *dentry;
struct vfsmount *mnt;
};
/* The per-task audit context. */
struct audit_context {
@ -553,6 +559,11 @@ static inline void audit_free_aux(struct audit_context *context)
struct audit_aux_data *aux;
while ((aux = context->aux)) {
if (aux->type == AUDIT_AVC_PATH) {
struct audit_aux_data_path *axi = (void *)aux;
dput(axi->dentry);
mntput(axi->mnt);
}
context->aux = aux->next;
kfree(aux);
}
@ -724,6 +735,14 @@ static void audit_log_exit(struct audit_context *context)
audit_log_format(ab, "saddr=");
audit_log_hex(ab, axs->a, axs->len);
break; }
case AUDIT_AVC_PATH: {
struct audit_aux_data_path *axi = (void *)aux;
audit_log_d_path(ab, "path=", axi->dentry, axi->mnt);
dput(axi->dentry);
mntput(axi->mnt);
break; }
}
audit_log_end(ab);
@ -1124,6 +1143,27 @@ int audit_sockaddr(int len, void *a)
return 0;
}
int audit_avc_path(struct dentry *dentry, struct vfsmount *mnt)
{
struct audit_aux_data_path *ax;
struct audit_context *context = current->audit_context;
if (likely(!context))
return 0;
ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
if (!ax)
return -ENOMEM;
ax->dentry = dget(dentry);
ax->mnt = mntget(mnt);
ax->d.type = AUDIT_AVC_PATH;
ax->d.next = context->aux;
context->aux = (void *)ax;
return 0;
}
void audit_signal_info(int sig, struct task_struct *t)
{
extern pid_t audit_sig_pid;

View file

@ -573,13 +573,10 @@ void avc_audit(u32 ssid, u32 tsid,
case AVC_AUDIT_DATA_FS:
if (a->u.fs.dentry) {
struct dentry *dentry = a->u.fs.dentry;
if (a->u.fs.mnt) {
audit_log_d_path(ab, "path=", dentry,
a->u.fs.mnt);
} else {
audit_log_format(ab, " name=%s",
dentry->d_name.name);
}
if (a->u.fs.mnt)
audit_avc_path(dentry, a->u.fs.mnt);
audit_log_format(ab, " name=%s",
dentry->d_name.name);
inode = dentry->d_inode;
} else if (a->u.fs.inode) {
struct dentry *dentry;
@ -630,8 +627,10 @@ void avc_audit(u32 ssid, u32 tsid,
case AF_UNIX:
u = unix_sk(sk);
if (u->dentry) {
audit_log_d_path(ab, "path=",
u->dentry, u->mnt);
audit_avc_path(u->dentry, u->mnt);
audit_log_format(ab, " name=%s",
u->dentry->d_name.name);
break;
}
if (!u->addr)