aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
author <dwmw2@shinybook.infradead.org>2005-04-29 15:54:44 +0100
committer <dwmw2@shinybook.infradead.org>2005-04-29 15:54:44 +0100
commit83c7d09173fdb6b06b109e65895392db3e49ac9c (patch)
tree3f48367a4d1413e221a5367bcd0cf8df7322c368
parentc60c390620e0abb60d4ae8c43583714bda27763f (diff)
AUDIT: Avoid log pollution by untrusted strings.
We log strings from userspace, such as arguments to open(). These could be formatted to contain \n followed by fake audit log entries. Provide a function for logging such strings, which gives a hex dump when the string contains anything but basic printable ASCII characters. Use it for logging filenames. Signed-off-by: David Woodhouse <dwmw2@infradead.org>
-rw-r--r--include/linux/audit.h8
-rw-r--r--kernel/audit.c23
-rw-r--r--kernel/auditsc.c7
3 files changed, 34 insertions, 4 deletions
diff --git a/include/linux/audit.h b/include/linux/audit.h
index 3628f7cfb17..9b77992c488 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -174,11 +174,15 @@ extern void audit_log_format(struct audit_buffer *ab,
const char *fmt, ...)
__attribute__((format(printf,2,3)));
extern void audit_log_end(struct audit_buffer *ab);
+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,
+ const char *string);
extern void audit_log_d_path(struct audit_buffer *ab,
const char *prefix,
struct dentry *dentry,
struct vfsmount *vfsmnt);
-
/* Private API (for auditsc.c only) */
extern void audit_send_reply(int pid, int seq, int type,
int done, int multi,
@@ -190,6 +194,8 @@ extern void audit_log_lost(const char *message);
#define audit_log_vformat(b,f,a) do { ; } while (0)
#define audit_log_format(b,f,...) do { ; } while (0)
#define audit_log_end(b) do { ; } while (0)
+#define audit_log_hex(a,b,l) do { ; } while (0)
+#define audit_log_untrustedstring(a,s) do { ; } while (0)
#define audit_log_d_path(b,p,d,v) do { ; } while (0)
#endif
#endif
diff --git a/kernel/audit.c b/kernel/audit.c
index 0f84dd7af2c..dca7b99615d 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -720,6 +720,29 @@ void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
va_end(args);
}
+void audit_log_hex(struct audit_buffer *ab, const unsigned char *buf, size_t len)
+{
+ int i;
+
+ for (i=0; i<len; i++)
+ audit_log_format(ab, "%02x", buf[i]);
+}
+
+void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
+{
+ const char *p = string;
+
+ while (*p) {
+ if (*p == '"' || *p == ' ' || *p < 0x20 || *p > 0x7f) {
+ audit_log_hex(ab, string, strlen(string));
+ return;
+ }
+ p++;
+ }
+ audit_log_format(ab, "\"%s\"", string);
+}
+
+
/* This is a helper-function to print the d_path without using a static
* buffer or allocating another buffer in addition to the one in
* audit_buffer. */
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 6f1931381bc..00e87ffff13 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -696,9 +696,10 @@ static void audit_log_exit(struct audit_context *context)
if (!ab)
continue; /* audit_panic has been called */
audit_log_format(ab, "item=%d", i);
- if (context->names[i].name)
- audit_log_format(ab, " name=%s",
- context->names[i].name);
+ if (context->names[i].name) {
+ audit_log_format(ab, " name=");
+ audit_log_untrustedstring(ab, context->names[i].name);
+ }
if (context->names[i].ino != (unsigned long)-1)
audit_log_format(ab, " inode=%lu dev=%02x:%02x mode=%#o"
" uid=%d gid=%d rdev=%02x:%02x",