[PATCH] execve argument logging

Alexander Viro
2006-04-21T11:33:28Z

diff --git a/fs/exec.c b/fs/exec.c
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -49,6 +49,7 @@
#include <linux/rmap.h>
#include <linux/acct.h>
#include <linux/cn_proc.h>
+#include <linux/audit.h>

#include <asm/uaccess.h>
#include <asm/mmu_context.h>
@@ -1085,6 +1086,11 @@ int search_binary_handler(struct linux_b
/* kernel module loader fixup */
/* so we don't try to load run modprobe in kernel space. */
set_fs(USER_DS);
+
+ retval = audit_bprm(bprm);
+ if (retval)
+ return retval;
+
retval = -ENOENT;
for (try=0; try<2; try++) {
read_lock(&binfmt_lock);
diff --git a/include/linux/audit.h b/include/linux/audit.h
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -83,6 +83,7 @@
#define AUDIT_CONFIG_CHANGE 1305 /* Audit system configuration change */
#define AUDIT_SOCKADDR 1306 /* sockaddr copied as syscall arg */
#define AUDIT_CWD 1307 /* Current working directory */
+#define AUDIT_EXECVE 1309 /* execve arguments */
#define AUDIT_IPC_SET_PERM 1311 /* IPC new permissions record type */

#define AUDIT_AVC 1400 /* SE Linux avc denial or grant */
@@ -283,6 +284,7 @@ struct audit_buffer;
struct audit_context;
struct inode;
struct netlink_skb_parms;
+struct linux_binprm;

#define AUDITSC_INVALID 0
#define AUDITSC_SUCCESS 1
@@ -322,6 +324,7 @@ extern int audit_set_loginuid(struct ta
extern uid_t audit_get_loginuid(struct audit_context *ctx);
extern int audit_ipc_obj(struct kern_ipc_perm *ipcp);
extern int audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mode, struct kern_ipc_perm *ipcp);
+extern int audit_bprm(struct linux_binprm *bprm);
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);
@@ -342,6 +345,7 @@ extern int audit_set_macxattr(const char
#define audit_get_loginuid(c) ({ -1; })
#define audit_ipc_obj(i) ({ 0; })
#define audit_ipc_set_perm(q,u,g,m,i) ({ 0; })
+#define audit_bprm(p) ({ 0; })
#define audit_socketcall(n,a) ({ 0; })
#define audit_sockaddr(len, addr) ({ 0; })
#define audit_avc_path(dentry, mnt) ({ 0; })
@@ -364,7 +368,7 @@ extern void audit_log_end(struct au
extern void audit_log_hex(struct audit_buffer *ab,
const unsigned char *buf,
size_t len);
-extern void audit_log_untrustedstring(struct audit_buffer *ab,
+extern const char * audit_log_untrustedstring(struct audit_buffer *ab,
const char *string);
extern void audit_log_d_path(struct audit_buffer *ab,
const char *prefix,
diff --git a/kernel/audit.c b/kernel/audit.c
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -998,18 +998,20 @@ void audit_log_hex(struct audit_buffer *
* or a space. Unescaped strings will start and end with a double quote mark.
* Strings that are escaped are printed in hex (2 digits per char).
*/
-void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
+const char *audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
{
const unsigned char *p = string;
+ size_t len = strlen(string);

while (*p) {
if (*p == '"' || *p < 0x21 || *p > 0x7f) {
- audit_log_hex(ab, string, strlen(string));
- return;
+ audit_log_hex(ab, string, len);
+ return string + len + 1;
}
p++;
}
audit_log_format(ab, "\"%s\"", string);
+ return p + 1;
}

/* This is a helper-function to print the escaped d_path */
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -59,6 +59,7 @@
#include <linux/list.h>
#include <linux/tty.h>
#include <linux/selinux.h>
+#include <linux/binfmts.h>

#include "audit.h"

@@ -110,6 +111,13 @@ struct audit_aux_data_ipcctl {
u32 osid;
};

+struct audit_aux_data_execve {
+ struct audit_aux_data d;
+ int argc;
+ int envc;
+ char mem[0];
+};
+
struct audit_aux_data_socketcall {
struct audit_aux_data d;
int nargs;
@@ -667,6 +675,16 @@ static void audit_log_exit(struct audit_
kfree(ctx);
}
break; }
+ case AUDIT_EXECVE: {
+ struct audit_aux_data_execve *axi = (void *)aux;
+ int i;
+ char *p;
+ for (i = 0, p = axi->mem; i < axi->argc; i++) {
+ audit_log_format(ab, "a%d=", i);
+ p = audit_log_untrustedstring(ab, p);
+ audit_log_format(ab, "\n");
+ }
+ break; }

case AUDIT_SOCKETCALL: {
int i;
@@ -1231,6 +1249,39 @@ int audit_ipc_set_perm(unsigned long qby
return 0;
}

+int audit_bprm(struct linux_binprm *bprm)
+{
+ struct audit_aux_data_execve *ax;
+ struct audit_context *context = current->audit_context;
+ unsigned long p, next;
+ void *to;
+
+ if (likely(!audit_enabled || !context))
+ return 0;
+
+ ax = kmalloc(sizeof(*ax) + PAGE_SIZE * MAX_ARG_PAGES - bprm->p,
+ GFP_KERNEL);
+ if (!ax)
+ return -ENOMEM;
+
+ ax->argc = bprm->argc;
+ ax->envc = bprm->envc;
+ for (p = bprm->p, to = ax->mem; p < MAX_ARG_PAGES*PAGE_SIZE; p = next) {
+ struct page *page = bprm->page[p / PAGE_SIZE];
+ void *kaddr = kmap(page);
+ next = (p + PAGE_SIZE) & ~(PAGE_SIZE - 1);
+ memcpy(to, kaddr + (p & (PAGE_SIZE - 1)), next - p);
+ to += next - p;
+ kunmap(page);
+ }
+
+ ax->d.type = AUDIT_EXECVE;
+ ax->d.next = context->aux;
+ context->aux = (void *)ax;
+ return 0;
+}
+
+
/**
* audit_socketcall - record audit data for sys_socketcall
* @nargs: number of args