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authorLinus Torvalds <torvalds@linux-foundation.org>2012-10-13 10:04:42 +0900
committerLinus Torvalds <torvalds@linux-foundation.org>2012-10-13 10:04:42 +0900
commit8418263e3547ed3816475e4c55a77004f0426ee6 (patch)
tree97c548b16e6753e1911870d824a07b7e726b6229 /kernel
parentccff9b1db693062b0a9c9070f4304deb47ef215c (diff)
parentf81700bd831efcd12eb7f0e66b24b16c2ad00a32 (diff)
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull third pile of VFS updates from Al Viro: "Stuff from Jeff Layton, mostly. Sanitizing interplay between audit and namei, removing a lot of insanity from audit_inode() mess and getting things ready for his ESTALE patchset." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: procfs: don't need a PATH_MAX allocation to hold a string representation of an int vfs: embed struct filename inside of names_cache allocation if possible audit: make audit_inode take struct filename vfs: make path_openat take a struct filename pointer vfs: turn do_path_lookup into wrapper around struct filename variant audit: allow audit code to satisfy getname requests from its names_list vfs: define struct filename and have getname() return it vfs: unexport getname and putname symbols acct: constify the name arg to acct_on vfs: allocate page instead of names_cache buffer in mount_block_root audit: overhaul __audit_inode_child to accomodate retrying audit: optimize audit_compare_dname_path audit: make audit_compare_dname_path use parent_len helper audit: remove dirlen argument to audit_compare_dname_path audit: set the name_len in audit_inode for parent lookups audit: add a new "type" field to audit_names struct audit: reverse arguments to audit_inode_child audit: no need to walk list in audit_inode if name is NULL audit: pass in dentry to audit_copy_inode wherever possible audit: remove unnecessary NULL ptr checks from do_path_lookup
Diffstat (limited to 'kernel')
-rw-r--r--kernel/acct.c6
-rw-r--r--kernel/audit.h7
-rw-r--r--kernel/audit_watch.c3
-rw-r--r--kernel/auditfilter.c65
-rw-r--r--kernel/auditsc.c217
5 files changed, 199 insertions, 99 deletions
diff --git a/kernel/acct.c b/kernel/acct.c
index 6cd7529c9e6a..051e071a06e7 100644
--- a/kernel/acct.c
+++ b/kernel/acct.c
@@ -193,7 +193,7 @@ static void acct_file_reopen(struct bsd_acct_struct *acct, struct file *file,
}
}
-static int acct_on(char *name)
+static int acct_on(struct filename *pathname)
{
struct file *file;
struct vfsmount *mnt;
@@ -201,7 +201,7 @@ static int acct_on(char *name)
struct bsd_acct_struct *acct = NULL;
/* Difference from BSD - they don't do O_APPEND */
- file = filp_open(name, O_WRONLY|O_APPEND|O_LARGEFILE, 0);
+ file = file_open_name(pathname, O_WRONLY|O_APPEND|O_LARGEFILE, 0);
if (IS_ERR(file))
return PTR_ERR(file);
@@ -260,7 +260,7 @@ SYSCALL_DEFINE1(acct, const char __user *, name)
return -EPERM;
if (name) {
- char *tmp = getname(name);
+ struct filename *tmp = getname(name);
if (IS_ERR(tmp))
return (PTR_ERR(tmp));
error = acct_on(tmp);
diff --git a/kernel/audit.h b/kernel/audit.h
index 9eb3d79482b6..d51cba868e1b 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -74,12 +74,15 @@ static inline int audit_hash_ino(u32 ino)
return (ino & (AUDIT_INODE_BUCKETS-1));
}
+/* Indicates that audit should log the full pathname. */
+#define AUDIT_NAME_FULL -1
+
extern int audit_match_class(int class, unsigned syscall);
extern int audit_comparator(const u32 left, const u32 op, const u32 right);
extern int audit_uid_comparator(kuid_t left, u32 op, kuid_t right);
extern int audit_gid_comparator(kgid_t left, u32 op, kgid_t right);
-extern int audit_compare_dname_path(const char *dname, const char *path,
- int *dirlen);
+extern int parent_len(const char *path);
+extern int audit_compare_dname_path(const char *dname, const char *path, int plen);
extern struct sk_buff * audit_make_reply(int pid, int seq, int type,
int done, int multi,
const void *payload, int size);
diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c
index 1c22ec3d87bc..9a9ae6e3d290 100644
--- a/kernel/audit_watch.c
+++ b/kernel/audit_watch.c
@@ -265,7 +265,8 @@ static void audit_update_watch(struct audit_parent *parent,
/* Run all of the watches on this parent looking for the one that
* matches the given dname */
list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) {
- if (audit_compare_dname_path(dname, owatch->path, NULL))
+ if (audit_compare_dname_path(dname, owatch->path,
+ AUDIT_NAME_FULL))
continue;
/* If the update involves invalidating rules, do the inode-based
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index c4bcdbaf4d4d..7f19f23d38a3 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -1298,41 +1298,60 @@ int audit_gid_comparator(kgid_t left, u32 op, kgid_t 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 *dirlen)
+/**
+ * parent_len - find the length of the parent portion of a pathname
+ * @path: pathname of which to determine length
+ */
+int parent_len(const char *path)
{
- int dlen, plen;
+ int plen;
const char *p;
- if (!dname || !path)
- return 1;
-
- dlen = strlen(dname);
plen = strlen(path);
- if (plen < dlen)
- return 1;
+
+ if (plen == 0)
+ return plen;
/* disregard trailing slashes */
p = path + plen - 1;
while ((*p == '/') && (p > path))
p--;
- /* find last path component */
- p = p - dlen + 1;
- if (p < path)
+ /* walk backward until we find the next slash or hit beginning */
+ while ((*p != '/') && (p > path))
+ p--;
+
+ /* did we find a slash? Then increment to include it in path */
+ if (*p == '/')
+ p++;
+
+ return p - path;
+}
+
+/**
+ * audit_compare_dname_path - compare given dentry name with last component in
+ * given path. Return of 0 indicates a match.
+ * @dname: dentry name that we're comparing
+ * @path: full pathname that we're comparing
+ * @parentlen: length of the parent if known. Passing in AUDIT_NAME_FULL
+ * here indicates that we must compute this value.
+ */
+int audit_compare_dname_path(const char *dname, const char *path, int parentlen)
+{
+ int dlen, pathlen;
+ const char *p;
+
+ dlen = strlen(dname);
+ pathlen = strlen(path);
+ if (pathlen < dlen)
return 1;
- else if (p > path) {
- if (*--p != '/')
- return 1;
- else
- p++;
- }
- /* return length of path's directory component */
- if (dirlen)
- *dirlen = p - path;
+ parentlen = parentlen == AUDIT_NAME_FULL ? parent_len(path) : parentlen;
+ if (pathlen - parentlen != dlen)
+ return 1;
+
+ p = path + parentlen;
+
return strncmp(p, dname, dlen);
}
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index f4a7756f999c..2f186ed80c40 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -81,9 +81,6 @@
* a name dynamically and also add those to the list anchored by names_list. */
#define AUDIT_NAMES 5
-/* Indicates that audit should log the full pathname. */
-#define AUDIT_NAME_FULL -1
-
/* no execve audit message should be longer than this (userspace limits) */
#define MAX_EXECVE_AUDIT_LEN 7500
@@ -106,27 +103,29 @@ struct audit_cap_data {
* we don't let putname() free it (instead we free all of the saved
* pointers at syscall exit time).
*
- * Further, in fs/namei.c:path_lookup() we store the inode and device. */
+ * Further, in fs/namei.c:path_lookup() we store the inode and device.
+ */
struct audit_names {
- struct list_head list; /* audit_context->names_list */
- const char *name;
- unsigned long ino;
- dev_t dev;
- umode_t mode;
- kuid_t uid;
- kgid_t gid;
- dev_t rdev;
- u32 osid;
- struct audit_cap_data fcap;
- unsigned int fcap_ver;
- int name_len; /* number of name's characters to log */
- bool name_put; /* call __putname() for this name */
+ struct list_head list; /* audit_context->names_list */
+ struct filename *name;
+ unsigned long ino;
+ dev_t dev;
+ umode_t mode;
+ kuid_t uid;
+ kgid_t gid;
+ dev_t rdev;
+ u32 osid;
+ struct audit_cap_data fcap;
+ unsigned int fcap_ver;
+ int name_len; /* number of name's characters to log */
+ unsigned char type; /* record type */
+ bool name_put; /* call __putname() for this name */
/*
* This was an allocated audit_names and not from the array of
* names allocated in the task audit context. Thus this name
* should be freed on syscall exit
*/
- bool should_free;
+ bool should_free;
};
struct audit_aux_data {
@@ -998,7 +997,7 @@ static inline void audit_free_names(struct audit_context *context)
context->ino_count);
list_for_each_entry(n, &context->names_list, list) {
printk(KERN_ERR "names[%d] = %p = %s\n", i,
- n->name, n->name ?: "(null)");
+ n->name, n->name->name ?: "(null)");
}
dump_stack();
return;
@@ -1555,7 +1554,7 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
case AUDIT_NAME_FULL:
/* log the full path */
audit_log_format(ab, " name=");
- audit_log_untrustedstring(ab, n->name);
+ audit_log_untrustedstring(ab, n->name->name);
break;
case 0:
/* name was specified as a relative path and the
@@ -1565,7 +1564,7 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
default:
/* log the name's directory component */
audit_log_format(ab, " name=");
- audit_log_n_untrustedstring(ab, n->name,
+ audit_log_n_untrustedstring(ab, n->name->name,
n->name_len);
}
} else
@@ -1995,7 +1994,8 @@ retry:
#endif
}
-static struct audit_names *audit_alloc_name(struct audit_context *context)
+static struct audit_names *audit_alloc_name(struct audit_context *context,
+ unsigned char type)
{
struct audit_names *aname;
@@ -2010,6 +2010,7 @@ static struct audit_names *audit_alloc_name(struct audit_context *context)
}
aname->ino = (unsigned long)-1;
+ aname->type = type;
list_add_tail(&aname->list, &context->names_list);
context->name_count++;
@@ -2020,13 +2021,36 @@ static struct audit_names *audit_alloc_name(struct audit_context *context)
}
/**
+ * audit_reusename - fill out filename with info from existing entry
+ * @uptr: userland ptr to pathname
+ *
+ * Search the audit_names list for the current audit context. If there is an
+ * existing entry with a matching "uptr" then return the filename
+ * associated with that audit_name. If not, return NULL.
+ */
+struct filename *
+__audit_reusename(const __user char *uptr)
+{
+ struct audit_context *context = current->audit_context;
+ struct audit_names *n;
+
+ list_for_each_entry(n, &context->names_list, list) {
+ if (!n->name)
+ continue;
+ if (n->name->uptr == uptr)
+ return n->name;
+ }
+ return NULL;
+}
+
+/**
* audit_getname - add a name to the list
* @name: name to add
*
* Add a name to the list of audit names for this context.
* Called from fs/namei.c:getname().
*/
-void __audit_getname(const char *name)
+void __audit_getname(struct filename *name)
{
struct audit_context *context = current->audit_context;
struct audit_names *n;
@@ -2040,13 +2064,19 @@ void __audit_getname(const char *name)
return;
}
- n = audit_alloc_name(context);
+#if AUDIT_DEBUG
+ /* The filename _must_ have a populated ->name */
+ BUG_ON(!name->name);
+#endif
+
+ n = audit_alloc_name(context, AUDIT_TYPE_UNKNOWN);
if (!n)
return;
n->name = name;
n->name_len = AUDIT_NAME_FULL;
n->name_put = true;
+ name->aname = n;
if (!context->pwd.dentry)
get_fs_pwd(current->fs, &context->pwd);
@@ -2059,7 +2089,7 @@ void __audit_getname(const char *name)
* then we delay the putname until syscall exit.
* Called from include/linux/fs.h:putname().
*/
-void audit_putname(const char *name)
+void audit_putname(struct filename *name)
{
struct audit_context *context = current->audit_context;
@@ -2074,7 +2104,7 @@ void audit_putname(const char *name)
list_for_each_entry(n, &context->names_list, list)
printk(KERN_ERR "name[%d] = %p = %s\n", i,
- n->name, n->name ?: "(null)");
+ n->name, n->name->name ?: "(null)");
}
#endif
__putname(name);
@@ -2088,8 +2118,8 @@ void audit_putname(const char *name)
" put_count=%d\n",
__FILE__, __LINE__,
context->serial, context->major,
- context->in_syscall, name, context->name_count,
- context->put_count);
+ context->in_syscall, name->name,
+ context->name_count, context->put_count);
dump_stack();
}
}
@@ -2132,13 +2162,13 @@ static void audit_copy_inode(struct audit_names *name, const struct dentry *dent
}
/**
- * audit_inode - store the inode and device from a lookup
+ * __audit_inode - store the inode and device from a lookup
* @name: name being audited
* @dentry: dentry being audited
- *
- * Called from fs/namei.c:path_lookup().
+ * @parent: does this dentry represent the parent?
*/
-void __audit_inode(const char *name, const struct dentry *dentry)
+void __audit_inode(struct filename *name, const struct dentry *dentry,
+ unsigned int parent)
{
struct audit_context *context = current->audit_context;
const struct inode *inode = dentry->d_inode;
@@ -2147,24 +2177,69 @@ void __audit_inode(const char *name, const struct dentry *dentry)
if (!context->in_syscall)
return;
+ if (!name)
+ goto out_alloc;
+
+#if AUDIT_DEBUG
+ /* The struct filename _must_ have a populated ->name */
+ BUG_ON(!name->name);
+#endif
+ /*
+ * If we have a pointer to an audit_names entry already, then we can
+ * just use it directly if the type is correct.
+ */
+ n = name->aname;
+ if (n) {
+ if (parent) {
+ if (n->type == AUDIT_TYPE_PARENT ||
+ n->type == AUDIT_TYPE_UNKNOWN)
+ goto out;
+ } else {
+ if (n->type != AUDIT_TYPE_PARENT)
+ goto out;
+ }
+ }
+
list_for_each_entry_reverse(n, &context->names_list, list) {
- if (n->name && (n->name == name))
- goto out;
+ /* does the name pointer match? */
+ if (!n->name || n->name->name != name->name)
+ continue;
+
+ /* match the correct record type */
+ if (parent) {
+ if (n->type == AUDIT_TYPE_PARENT ||
+ n->type == AUDIT_TYPE_UNKNOWN)
+ goto out;
+ } else {
+ if (n->type != AUDIT_TYPE_PARENT)
+ goto out;
+ }
}
- /* unable to find the name from a previous getname() */
- n = audit_alloc_name(context);
+out_alloc:
+ /* unable to find the name from a previous getname(). Allocate a new
+ * anonymous entry.
+ */
+ n = audit_alloc_name(context, AUDIT_TYPE_NORMAL);
if (!n)
return;
out:
+ if (parent) {
+ n->name_len = n->name ? parent_len(n->name->name) : AUDIT_NAME_FULL;
+ n->type = AUDIT_TYPE_PARENT;
+ } else {
+ n->name_len = AUDIT_NAME_FULL;
+ n->type = AUDIT_TYPE_NORMAL;
+ }
handle_path(dentry);
audit_copy_inode(n, dentry, inode);
}
/**
- * audit_inode_child - collect inode info for created/removed objects
- * @dentry: dentry being audited
+ * __audit_inode_child - collect inode info for created/removed objects
* @parent: inode of dentry parent
+ * @dentry: dentry being audited
+ * @type: AUDIT_TYPE_* value that we're looking for
*
* For syscalls that create or remove filesystem objects, audit_inode
* can only collect information for the filesystem object's parent.
@@ -2174,15 +2249,14 @@ out:
* must be hooked prior, in order to capture the target inode during
* unsuccessful attempts.
*/
-void __audit_inode_child(const struct dentry *dentry,
- const struct inode *parent)
+void __audit_inode_child(const struct inode *parent,
+ const struct dentry *dentry,
+ const unsigned char type)
{
struct audit_context *context = current->audit_context;
- const char *found_parent = NULL, *found_child = NULL;
const struct inode *inode = dentry->d_inode;
const char *dname = dentry->d_name.name;
- struct audit_names *n;
- int dirlen = 0;
+ struct audit_names *n, *found_parent = NULL, *found_child = NULL;
if (!context->in_syscall)
return;
@@ -2190,62 +2264,65 @@ void __audit_inode_child(const struct dentry *dentry,
if (inode)
handle_one(inode);
- /* parent is more likely, look for it first */
+ /* look for a parent entry first */
list_for_each_entry(n, &context->names_list, list) {
- if (!n->name)
+ if (!n->name || n->type != AUDIT_TYPE_PARENT)
continue;
if (n->ino == parent->i_ino &&
- !audit_compare_dname_path(dname, n->name, &dirlen)) {
- n->name_len = dirlen; /* update parent data in place */
- found_parent = n->name;
- goto add_names;
+ !audit_compare_dname_path(dname, n->name->name, n->name_len)) {
+ found_parent = n;
+ break;
}
}
- /* no matching parent, look for matching child */
+ /* is there a matching child entry? */
list_for_each_entry(n, &context->names_list, list) {
- if (!n->name)
+ /* can only match entries that have a name */
+ if (!n->name || n->type != type)
continue;
- /* strcmp() is the more likely scenario */
- if (!strcmp(dname, n->name) ||
- !audit_compare_dname_path(dname, n->name, &dirlen)) {
- if (inode)
- audit_copy_inode(n, NULL, inode);
- else
- n->ino = (unsigned long)-1;
- found_child = n->name;
- goto add_names;
+ /* if we found a parent, make sure this one is a child of it */
+ if (found_parent && (n->name != found_parent->name))
+ continue;
+
+ if (!strcmp(dname, n->name->name) ||
+ !audit_compare_dname_path(dname, n->name->name,
+ found_parent ?
+ found_parent->name_len :
+ AUDIT_NAME_FULL)) {
+ found_child = n;
+ break;
}
}
-add_names:
if (!found_parent) {
- n = audit_alloc_name(context);
+ /* create a new, "anonymous" parent record */
+ n = audit_alloc_name(context, AUDIT_TYPE_PARENT);
if (!n)
return;
audit_copy_inode(n, NULL, parent);
}
if (!found_child) {
- n = audit_alloc_name(context);
- if (!n)
+ found_child = audit_alloc_name(context, type);
+ if (!found_child)
return;
/* Re-use the name belonging to the slot for a matching parent
* directory. All names for this context are relinquished in
* audit_free_names() */
if (found_parent) {
- n->name = found_parent;
- n->name_len = AUDIT_NAME_FULL;
+ found_child->name = found_parent->name;
+ found_child->name_len = AUDIT_NAME_FULL;
/* don't call __putname() */
- n->name_put = false;
+ found_child->name_put = false;
}
-
- if (inode)
- audit_copy_inode(n, NULL, inode);
}
+ if (inode)
+ audit_copy_inode(found_child, dentry, inode);
+ else
+ found_child->ino = (unsigned long)-1;
}
EXPORT_SYMBOL_GPL(__audit_inode_child);