[PATCH] Audit: standardize string audit interfaces

This patch standardized the string auditing interfaces. No userspace changes will be visible and this is all just cleanup and consistancy work. We have the following string audit interfaces to use: void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf, size_t len); void audit_log_n_string(struct audit_buffer *ab, const char *buf, size_t n); void audit_log_string(struct audit_buffer *ab, const char *buf); void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string, size_t n); void audit_log_untrustedstring(struct audit_buffer *ab, const char *string); This may be the first step to possibly fixing some of the issues that people have with the string output from the kernel audit system. But we still don't have an agreed upon solution to that problem. Signed-off-by: Eric Paris <eparis(a)redhat.com&gt; --- drivers/char/tty_audit.c | 2 +- include/linux/audit.h | 22 ++++++++++++++-------- kernel/audit.c | 19 +++++++++---------- kernel/auditsc.c | 8 ++++---- security/selinux/avc.c | 2 +- 5 files changed, 29 insertions(+), 24 deletions(-) diff --git a/drivers/char/tty_audit.c b/drivers/char/tty_audit.c index 7722466..ae032c5 100644 --- a/drivers/char/tty_audit.c +++ b/drivers/char/tty_audit.c @@ -92,7 +92,7 @@ static void tty_audit_buf_push(struct task_struct *tsk, uid_t loginuid, get_task_comm(name, tsk); audit_log_untrustedstring(ab, name); audit_log_format(ab, " data="); - audit_log_n_untrustedstring(ab, buf->valid, buf->data); + audit_log_n_untrustedstring(ab, buf->data, buf->valid); audit_log_end(ab); } buf->valid = 0; diff --git a/include/linux/audit.h b/include/linux/audit.h index 2af9ec0..93afdc5 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -522,16 +522,20 @@ 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 int audit_string_contains_control(const char *string, size_t len); +extern void audit_log_n_hex(struct audit_buffer *ab, + const unsigned char *buf, + size_t len); +extern void audit_log_n_string(struct audit_buffer *ab, + const char *buf, + size_t n); +#define audit_log_string(a,b) audit_log_n_string(a, b, strlen(b)); +extern void audit_log_n_untrustedstring(struct audit_buffer *ab, + const char *string, + size_t n); extern void audit_log_untrustedstring(struct audit_buffer *ab, const char *string); -extern void audit_log_n_untrustedstring(struct audit_buffer *ab, - size_t n, - const char *string); extern void audit_log_d_path(struct audit_buffer *ab, const char *prefix, struct path *path); @@ -548,9 +552,11 @@ extern int audit_enabled; #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_n_hex(a,b,l) do { ; } while (0) +#define audit_log_n_string(a,c,l) do { ; } while (0) +#define audit_log_string(a,c) do { ; } while (0) #define audit_log_n_untrustedstring(a,n,s) do { ; } while (0) +#define audit_log_untrustedstring(a,s) do { ; } while (0) #define audit_log_d_path(b, p, d) do { ; } while (0) #define audit_enabled 0 #endif diff --git a/kernel/audit.c b/kernel/audit.c index 10c4930..a79d6d6 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -659,8 +659,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) audit_log_format(ab, " msg="); size = nlmsg_len(nlh); - audit_log_n_untrustedstring(ab, size, - data); + audit_log_n_untrustedstring(ab, data, size); } audit_set_pid(ab, pid); audit_log_end(ab); @@ -1198,7 +1197,7 @@ void audit_log_format(struct audit_buffer *ab, const char *fmt, ...) * This function will take the passed buf and convert it into a string of * ascii hex digits. The new string is placed onto the skb. */ -void audit_log_hex(struct audit_buffer *ab, const unsigned char *buf, +void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf, size_t len) { int i, avail, new_len; @@ -1234,8 +1233,8 @@ void audit_log_hex(struct audit_buffer *ab, const unsigned char *buf, * Format a string of no more than slen characters into the audit buffer, * enclosed in quote marks. */ -static void audit_log_n_string(struct audit_buffer *ab, size_t slen, - const char *string) +void audit_log_n_string(struct audit_buffer *ab, const char *string, + size_t slen) { int avail, new_len; unsigned char *ptr; @@ -1291,13 +1290,13 @@ int audit_string_contains_control(const char *string, size_t len) * The caller specifies the number of characters in the string to log, which may * or may not be the entire string. */ -void audit_log_n_untrustedstring(struct audit_buffer *ab, size_t len, - const char *string) +void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string, + size_t len) { if (audit_string_contains_control(string, len)) - audit_log_hex(ab, string, len); + audit_log_n_hex(ab, string, len); else - audit_log_n_string(ab, len, string); + audit_log_n_string(ab, string, len); } /** @@ -1310,7 +1309,7 @@ void audit_log_n_untrustedstring(struct audit_buffer *ab, size_t len, */ void audit_log_untrustedstring(struct audit_buffer *ab, const char *string) { - audit_log_n_untrustedstring(ab, strlen(string), string); + audit_log_n_untrustedstring(ab, string, strlen(string)); } /* This is a helper-function to print the escaped d_path */ diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 782262e..62ad0d7 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -1095,7 +1095,7 @@ static int audit_log_single_execve_arg(struct audit_context *context, audit_log_format(*ab, "[%d]", i); audit_log_format(*ab, "="); if (has_cntl) - audit_log_hex(*ab, buf, to_send); + audit_log_n_hex(*ab, buf, to_send); else audit_log_format(*ab, "\"%s\"", buf); audit_log_format(*ab, "\n"); @@ -1306,7 +1306,7 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts struct audit_aux_data_sockaddr *axs = (void *)aux; audit_log_format(ab, "saddr="); - audit_log_hex(ab, axs->a, axs->len); + audit_log_n_hex(ab, axs->a, axs->len); break; } case AUDIT_FD_PAIR: { @@ -1370,8 +1370,8 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts default: /* log the name's directory component */ audit_log_format(ab, " name="); - audit_log_n_untrustedstring(ab, n->name_len, - n->name); + audit_log_n_untrustedstring(ab, n->name, + n->name_len); } } else audit_log_format(ab, " name=(null)"); diff --git a/security/selinux/avc.c b/security/selinux/avc.c index 187964e..bd67c2c 100644 --- a/security/selinux/avc.c +++ b/security/selinux/avc.c @@ -643,7 +643,7 @@ void avc_audit(u32 ssid, u32 tsid, if (*p) audit_log_untrustedstring(ab, p); else - audit_log_hex(ab, p, len); + audit_log_n_hex(ab, p, len); break; } }