[PATCH] log more info for directory entry change events
When an audit event involves changes to a directory entry, include
a PATH record for the directory itself. A few other notable changes:
- fixed audit_inode_child() hooks in fsnotify_move()
- removed unused flags arg from audit_inode()
- added audit log routines for logging a portion of a string
Here's some sample output.
before patch:
type=SYSCALL msg=audit(1149821605.320:26): arch=40000003 syscall=39 success=yes exit=0 a0=bf8d3c7c a1=1ff a2=804e1b8 a3=bf8d3c7c items=1 ppid=739 pid=800 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=ttyS0 comm="mkdir" exe="/bin/mkdir" subj=root:system_r:unconfined_t:s0-s0:c0.c255
type=CWD msg=audit(1149821605.320:26): cwd="/root"
type=PATH msg=audit(1149821605.320:26): item=0 name="foo" parent=164068 inode=164010 dev=03:00 mode=040755 ouid=0 ogid=0 rdev=00:00 obj=root:object_r:user_home_t:s0
after patch:
type=SYSCALL msg=audit(1149822032.332:24): arch=40000003 syscall=39 success=yes exit=0 a0=bfdd9c7c a1=1ff a2=804e1b8 a3=bfdd9c7c items=2 ppid=714 pid=777 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=ttyS0 comm="mkdir" exe="/bin/mkdir" subj=root:system_r:unconfined_t:s0-s0:c0.c255
type=CWD msg=audit(1149822032.332:24): cwd="/root"
type=PATH msg=audit(1149822032.332:24): item=0 name="/root" inode=164068 dev=03:00 mode=040750 ouid=0 ogid=0 rdev=00:00 obj=root:object_r:user_home_dir_t:s0
type=PATH msg=audit(1149822032.332:24): item=1 name="foo" inode=164010 dev=03:00 mode=040755 ouid=0 ogid=0 rdev=00:00 obj=root:object_r:user_home_t:s0
Signed-off-by: Amy Griffis <amy.griffis@hp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/kernel/audit.c b/kernel/audit.c
index 0fbf1c1..7dfac70 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1051,20 +1051,53 @@
skb_put(skb, len << 1); /* new string is twice the old string */
}
+/*
+ * 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)
+{
+ int avail, new_len;
+ unsigned char *ptr;
+ struct sk_buff *skb;
+
+ BUG_ON(!ab->skb);
+ skb = ab->skb;
+ avail = skb_tailroom(skb);
+ new_len = slen + 3; /* enclosing quotes + null terminator */
+ if (new_len > avail) {
+ avail = audit_expand(ab, new_len);
+ if (!avail)
+ return;
+ }
+ ptr = skb->tail;
+ *ptr++ = '"';
+ memcpy(ptr, string, slen);
+ ptr += slen;
+ *ptr++ = '"';
+ *ptr = 0;
+ skb_put(skb, slen + 2); /* don't include null terminator */
+}
+
/**
- * audit_log_unstrustedstring - log a string that may contain random characters
+ * audit_log_n_unstrustedstring - log a string that may contain random characters
* @ab: audit_buffer
+ * @len: lenth of string (not including trailing null)
* @string: string to be logged
*
* This code will escape a string that is passed to it if the string
* contains a control character, unprintable character, double quote mark,
* 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).
+ *
+ * The caller specifies the number of characters in the string to log, which may
+ * or may not be the entire string.
*/
-const char *audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
+const char *audit_log_n_untrustedstring(struct audit_buffer *ab, size_t len,
+ const char *string)
{
const unsigned char *p = string;
- size_t len = strlen(string);
while (*p) {
if (*p == '"' || *p < 0x21 || *p > 0x7f) {
@@ -1073,10 +1106,23 @@
}
p++;
}
- audit_log_format(ab, "\"%s\"", string);
+ audit_log_n_string(ab, len, string);
return p + 1;
}
+/**
+ * audit_log_unstrustedstring - log a string that may contain random characters
+ * @ab: audit_buffer
+ * @string: string to be logged
+ *
+ * Same as audit_log_n_unstrustedstring(), except that strlen is used to
+ * determine string length.
+ */
+const char *audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
+{
+ return audit_log_n_untrustedstring(ab, strlen(string), string);
+}
+
/* This is a helper-function to print the escaped d_path */
void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
struct dentry *dentry, struct vfsmount *vfsmnt)
diff --git a/kernel/audit.h b/kernel/audit.h
index 58fa44cb..8323e41 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -104,7 +104,8 @@
}
extern int audit_comparator(const u32 left, const u32 op, const u32 right);
-extern int audit_compare_dname_path(const char *dname, const char *path);
+extern int audit_compare_dname_path(const char *dname, const char *path,
+ int *dirlen);
extern struct sk_buff * audit_make_reply(int pid, int seq, int type,
int done, int multi,
void *payload, int size);
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index a536f71..4c99d2c 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -787,7 +787,7 @@
mutex_lock(&audit_filter_mutex);
list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) {
- if (audit_compare_dname_path(dname, owatch->path))
+ if (audit_compare_dname_path(dname, owatch->path, NULL))
continue;
/* If the update involves invalidating rules, do the inode-based
@@ -1387,7 +1387,8 @@
/* Compare given dentry name with last component in given path,
* return of 0 indicates a match. */
-int audit_compare_dname_path(const char *dname, const char *path)
+int audit_compare_dname_path(const char *dname, const char *path,
+ int *dirlen)
{
int dlen, plen;
const char *p;
@@ -1416,6 +1417,9 @@
p++;
}
+ /* return length of path's directory component */
+ if (dirlen)
+ *dirlen = p - path;
return strncmp(p, dname, dlen);
}
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 174a3f6..851ae02 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -82,6 +82,9 @@
* path_lookup. */
#define AUDIT_NAMES_RESERVED 7
+/* Indicates that audit should log the full pathname. */
+#define AUDIT_NAME_FULL -1
+
/* When fs/namei.c:getname() is called, we store the pointer in name and
* we don't let putname() free it (instead we free all of the saved
* pointers at syscall exit time).
@@ -89,8 +92,9 @@
* Further, in fs/namei.c:path_lookup() we store the inode and device. */
struct audit_names {
const char *name;
+ int name_len; /* number of name's characters to log */
+ unsigned name_put; /* call __putname() for this name */
unsigned long ino;
- unsigned long pino;
dev_t dev;
umode_t mode;
uid_t uid;
@@ -296,12 +300,10 @@
break;
case AUDIT_INODE:
if (name)
- result = (name->ino == f->val ||
- name->pino == f->val);
+ result = (name->ino == f->val);
else if (ctx) {
for (j = 0; j < ctx->name_count; j++) {
- if (audit_comparator(ctx->names[j].ino, f->op, f->val) ||
- audit_comparator(ctx->names[j].pino, f->op, f->val)) {
+ if (audit_comparator(ctx->names[j].ino, f->op, f->val)) {
++result;
break;
}
@@ -311,8 +313,7 @@
case AUDIT_WATCH:
if (name && rule->watch->ino != (unsigned long)-1)
result = (name->dev == rule->watch->dev &&
- (name->ino == rule->watch->ino ||
- name->pino == rule->watch->ino));
+ name->ino == rule->watch->ino);
break;
case AUDIT_LOGINUID:
result = 0;
@@ -526,7 +527,7 @@
#endif
for (i = 0; i < context->name_count; i++) {
- if (context->names[i].name)
+ if (context->names[i].name && context->names[i].name_put)
__putname(context->names[i].name);
}
context->name_count = 0;
@@ -850,8 +851,7 @@
}
}
for (i = 0; i < context->name_count; i++) {
- unsigned long ino = context->names[i].ino;
- unsigned long pino = context->names[i].pino;
+ struct audit_names *n = &context->names[i];
ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH);
if (!ab)
@@ -859,33 +859,47 @@
audit_log_format(ab, "item=%d", i);
- audit_log_format(ab, " name=");
- if (context->names[i].name)
- audit_log_untrustedstring(ab, context->names[i].name);
- else
- audit_log_format(ab, "(null)");
+ if (n->name) {
+ switch(n->name_len) {
+ case AUDIT_NAME_FULL:
+ /* log the full path */
+ audit_log_format(ab, " name=");
+ audit_log_untrustedstring(ab, n->name);
+ break;
+ case 0:
+ /* name was specified as a relative path and the
+ * directory component is the cwd */
+ audit_log_d_path(ab, " name=", context->pwd,
+ context->pwdmnt);
+ break;
+ default:
+ /* log the name's directory component */
+ audit_log_format(ab, " name=");
+ audit_log_n_untrustedstring(ab, n->name_len,
+ n->name);
+ }
+ } else
+ audit_log_format(ab, " name=(null)");
- if (pino != (unsigned long)-1)
- audit_log_format(ab, " parent=%lu", pino);
- if (ino != (unsigned long)-1)
- audit_log_format(ab, " inode=%lu", ino);
- if ((pino != (unsigned long)-1) || (ino != (unsigned long)-1))
- audit_log_format(ab, " dev=%02x:%02x mode=%#o"
- " ouid=%u ogid=%u rdev=%02x:%02x",
- MAJOR(context->names[i].dev),
- MINOR(context->names[i].dev),
- context->names[i].mode,
- context->names[i].uid,
- context->names[i].gid,
- MAJOR(context->names[i].rdev),
- MINOR(context->names[i].rdev));
- if (context->names[i].osid != 0) {
+ if (n->ino != (unsigned long)-1) {
+ audit_log_format(ab, " inode=%lu"
+ " dev=%02x:%02x mode=%#o"
+ " ouid=%u ogid=%u rdev=%02x:%02x",
+ n->ino,
+ MAJOR(n->dev),
+ MINOR(n->dev),
+ n->mode,
+ n->uid,
+ n->gid,
+ MAJOR(n->rdev),
+ MINOR(n->rdev));
+ }
+ if (n->osid != 0) {
char *ctx = NULL;
u32 len;
if (selinux_ctxid_to_string(
- context->names[i].osid, &ctx, &len)) {
- audit_log_format(ab, " osid=%u",
- context->names[i].osid);
+ n->osid, &ctx, &len)) {
+ audit_log_format(ab, " osid=%u", n->osid);
call_panic = 2;
} else
audit_log_format(ab, " obj=%s", ctx);
@@ -1075,6 +1089,8 @@
}
BUG_ON(context->name_count >= AUDIT_NAMES);
context->names[context->name_count].name = name;
+ context->names[context->name_count].name_len = AUDIT_NAME_FULL;
+ context->names[context->name_count].name_put = 1;
context->names[context->name_count].ino = (unsigned long)-1;
++context->name_count;
if (!context->pwd) {
@@ -1141,11 +1157,10 @@
* audit_inode - store the inode and device from a lookup
* @name: name being audited
* @inode: inode being audited
- * @flags: lookup flags (as used in path_lookup())
*
* Called from fs/namei.c:path_lookup().
*/
-void __audit_inode(const char *name, const struct inode *inode, unsigned flags)
+void __audit_inode(const char *name, const struct inode *inode)
{
int idx;
struct audit_context *context = current->audit_context;
@@ -1171,20 +1186,13 @@
++context->ino_count;
#endif
}
+ context->names[idx].ino = inode->i_ino;
context->names[idx].dev = inode->i_sb->s_dev;
context->names[idx].mode = inode->i_mode;
context->names[idx].uid = inode->i_uid;
context->names[idx].gid = inode->i_gid;
context->names[idx].rdev = inode->i_rdev;
audit_inode_context(idx, inode);
- if ((flags & LOOKUP_PARENT) && (strcmp(name, "/") != 0) &&
- (strcmp(name, ".") != 0)) {
- context->names[idx].ino = (unsigned long)-1;
- context->names[idx].pino = inode->i_ino;
- } else {
- context->names[idx].ino = inode->i_ino;
- context->names[idx].pino = (unsigned long)-1;
- }
}
/**
@@ -1206,34 +1214,40 @@
{
int idx;
struct audit_context *context = current->audit_context;
+ const char *found_name = NULL;
+ int dirlen = 0;
if (!context->in_syscall)
return;
/* determine matching parent */
if (!dname)
- goto no_match;
+ goto update_context;
for (idx = 0; idx < context->name_count; idx++)
- if (context->names[idx].pino == pino) {
+ if (context->names[idx].ino == pino) {
const char *name = context->names[idx].name;
if (!name)
continue;
- if (audit_compare_dname_path(dname, name) == 0)
- goto update_context;
+ if (audit_compare_dname_path(dname, name, &dirlen) == 0) {
+ context->names[idx].name_len = dirlen;
+ found_name = name;
+ break;
+ }
}
-no_match:
- /* catch-all in case match not found */
+update_context:
idx = context->name_count++;
- context->names[idx].name = NULL;
- context->names[idx].pino = pino;
#if AUDIT_DEBUG
context->ino_count++;
#endif
+ /* Re-use the name belonging to the slot for a matching parent directory.
+ * All names for this context are relinquished in audit_free_names() */
+ context->names[idx].name = found_name;
+ context->names[idx].name_len = AUDIT_NAME_FULL;
+ context->names[idx].name_put = 0; /* don't call __putname() */
-update_context:
if (inode) {
context->names[idx].ino = inode->i_ino;
context->names[idx].dev = inode->i_sb->s_dev;
@@ -1242,7 +1256,8 @@
context->names[idx].gid = inode->i_gid;
context->names[idx].rdev = inode->i_rdev;
audit_inode_context(idx, inode);
- }
+ } else
+ context->names[idx].ino = (unsigned long)-1;
}
/**