audit: ignore terminating NUL in AUDIT_USER_TTY messages

AUDIT_USER_TTY, like all other messages sent from user-space, is sent NUL-terminated. Unlike other user-space audit messages, which come only from trusted sources, AUDIT_USER_TTY messages are processed using audit_log_n_untrustedstring(). This patch modifies AUDIT_USER_TTY handling to ignore the trailing NUL and use the "quoted_string" representation of the message if possible. Signed-off-by: Miloslav Trmac <[email protected]> Cc: Eric Paris <[email protected]> Cc: Al Viro <[email protected]> Cc: Steve Grubb <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Al Viro <[email protected]>
mna · Apr 5, 2009 · 55ad2f8 · 55ad2f8
1 parent b3897f5
commit 55ad2f8
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/kernel/audit.c b/kernel/audit.c
@@ -766,6 +766,9 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 
 				audit_log_format(ab, " msg=");
 				size = nlmsg_len(nlh);
+				if (size > 0 &&
+				    ((unsigned char *)data)[size - 1] == '\0')
+					size--;
 				audit_log_n_untrustedstring(ab, data, size);
 			}
 			audit_set_pid(ab, pid);