[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/fs/namei.c b/fs/namei.c
index d6e2ee2..184fe4a 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1127,7 +1127,7 @@ out:
        if (likely(retval == 0)) {
                if (unlikely(current->audit_context && nd && nd->dentry &&
                                nd->dentry->d_inode))
-               audit_inode(name, nd->dentry->d_inode, flags);
+               audit_inode(name, nd->dentry->d_inode);
        }
 out_fail:
        return retval;

diff --git a/fs/open.c b/fs/open.c
index 317b7c7..4f178ac 100644 (file)
--- a/fs/open.c
+++ b/fs/open.c
@@ -633,7 +633,7 @@ asmlinkage long sys_fchmod(unsigned int fd, mode_t mode)
        dentry = file->f_dentry;
        inode = dentry->d_inode;
 
-       audit_inode(NULL, inode, 0);
+       audit_inode(NULL, inode);
 
        err = -EROFS;
        if (IS_RDONLY(inode))
@@ -786,7 +786,7 @@ asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group)
        if (file) {
                struct dentry * dentry;
                dentry = file->f_dentry;
-               audit_inode(NULL, dentry->d_inode, 0);
+               audit_inode(NULL, dentry->d_inode);
                error = chown_common(dentry, user, group);
                fput(file);
        }

diff --git a/fs/xattr.c b/fs/xattr.c
index e416190..c32f15b 100644 (file)
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -242,7 +242,7 @@ sys_fsetxattr(int fd, char __user *name, void __user *value,
        if (!f)
                return error;
        dentry = f->f_dentry;
-       audit_inode(NULL, dentry->d_inode, 0);
+       audit_inode(NULL, dentry->d_inode);
        error = setxattr(dentry, name, value, size, flags);
        fput(f);
        return error;
@@ -469,7 +469,7 @@ sys_fremovexattr(int fd, char __user *name)
        if (!f)
                return error;
        dentry = f->f_dentry;
-       audit_inode(NULL, dentry->d_inode, 0);
+       audit_inode(NULL, dentry->d_inode);
        error = removexattr(dentry, name);
        fput(f);
        return error;

diff --git a/include/linux/audit.h b/include/linux/audit.h
index c783275..e1c1dbd 100644 (file)
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -310,7 +310,7 @@ extern void audit_syscall_entry(int arch,
 extern void audit_syscall_exit(int failed, long return_code);
 extern void __audit_getname(const char *name);
 extern void audit_putname(const char *name);
-extern void __audit_inode(const char *name, const struct inode *inode, unsigned flags);
+extern void __audit_inode(const char *name, const struct inode *inode);
 extern void __audit_inode_child(const char *dname, const struct inode *inode,
                                unsigned long pino);
 static inline void audit_getname(const char *name)
@@ -318,10 +318,9 @@ static inline void audit_getname(const char *name)
        if (unlikely(current->audit_context))
                __audit_getname(name);
 }
-static inline void audit_inode(const char *name, const struct inode *inode,
-                              unsigned flags) {
+static inline void audit_inode(const char *name, const struct inode *inode) {
        if (unlikely(current->audit_context))
-               __audit_inode(name, inode, flags);
+               __audit_inode(name, inode);
 }
 static inline void audit_inode_child(const char *dname, 
                                     const struct inode *inode, 
@@ -398,9 +397,9 @@ static inline int audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
 #define audit_syscall_exit(f,r) do { ; } while (0)
 #define audit_getname(n) do { ; } while (0)
 #define audit_putname(n) do { ; } while (0)
-#define __audit_inode(n,i,f) do { ; } while (0)
+#define __audit_inode(n,i) do { ; } while (0)
 #define __audit_inode_child(d,i,p) do { ; } while (0)
-#define audit_inode(n,i,f) do { ; } while (0)
+#define audit_inode(n,i) do { ; } while (0)
 #define audit_inode_child(d,i,p) do { ; } while (0)
 #define auditsc_get_stamp(c,t,s) do { BUG(); } while (0)
 #define audit_get_loginuid(c) ({ -1; })
@@ -435,6 +434,9 @@ extern void             audit_log_hex(struct audit_buffer *ab,
                                          size_t len);
 extern const char *        audit_log_untrustedstring(struct audit_buffer *ab,
                                                      const char *string);
+extern const char *        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 dentry *dentry,
@@ -452,6 +454,7 @@ extern int  audit_receive_filter(int type, int pid, int uid, int seq,
 #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_untrustedstring(a,n,s) do { ; } while (0)
 #define audit_log_d_path(b,p,d,v) do { ; } while (0)
 #endif
 #endif

diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h
index a9d3044..cc5dec7 100644 (file)
--- a/include/linux/fsnotify.h
+++ b/include/linux/fsnotify.h
@@ -67,8 +67,7 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
        if (source) {
                inotify_inode_queue_event(source, IN_MOVE_SELF, 0, NULL, NULL);
        }
-       audit_inode_child(old_name, source, old_dir->i_ino);
-       audit_inode_child(new_name, target, new_dir->i_ino);
+       audit_inode_child(new_name, source, new_dir->i_ino);
 }
 
 /*

diff --git a/kernel/audit.c b/kernel/audit.c
index 0fbf1c1..7dfac70 100644 (file)
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1051,20 +1051,53 @@ void audit_log_hex(struct audit_buffer *ab, const unsigned char *buf,
        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 @@ const char *audit_log_untrustedstring(struct audit_buffer *ab, const char *strin
                }
                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 58fa44c..8323e41 100644 (file)
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -104,7 +104,8 @@ static inline int audit_hash_ino(u32 ino)
 }
 
 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 (file)
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -787,7 +787,7 @@ static void audit_update_watch(struct audit_parent *parent,
 
        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 @@ int audit_comparator(const u32 left, const u32 op, const u32 right)
 
 /* 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 @@ int audit_compare_dname_path(const char *dname, const char *path)
                        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 (file)
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -82,6 +82,9 @@ extern int audit_enabled;
  * 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 @@ extern int audit_enabled;
  * 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 @@ static int audit_filter_rules(struct task_struct *tsk,
                        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 @@ static int audit_filter_rules(struct task_struct *tsk,
                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 @@ static inline void audit_free_names(struct audit_context *context)
 #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 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
                }
        }
        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 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
 
                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 (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->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 (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 @@ void __audit_getname(const char *name)
        }
        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 @@ static void audit_inode_context(int idx, const struct inode *inode)
  * 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 @@ void __audit_inode(const char *name, const struct inode *inode, unsigned flags)
                ++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 @@ void __audit_inode_child(const char *dname, const struct inode *inode,
 {
        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 @@ update_context:
                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;
 }
 
 /**