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authorLinus Torvalds <torvalds@linux-foundation.org>2015-02-17 15:27:47 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2015-02-17 15:27:47 -0800
commit05016b0f0a9d900e976db7f50a7761c0aefe5a1c (patch)
tree20b2f04fee785dc9ef81596cb2f7deec6d8016e0 /kernel
parentc6b1de1b646fe232206d4065df4d14040cebd613 (diff)
parent55422d0bd292f5ad143cc32cb8bb8505257274c4 (diff)
downloadlinux-05016b0f0a9d900e976db7f50a7761c0aefe5a1c.tar.bz2
Merge branch 'getname2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull getname/putname updates from Al Viro: "Rework of getname/getname_kernel/etc., mostly from Paul Moore. Gets rid of quite a pile of kludges between namei and audit..." * 'getname2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: audit: replace getname()/putname() hacks with reference counters audit: fix filename matching in __audit_inode() and __audit_inode_child() audit: enable filename recording via getname_kernel() simpler calling conventions for filename_mountpoint() fs: create proper filename objects using getname_kernel() fs: rework getname_kernel to handle up to PATH_MAX sized filenames cut down the number of do_path_lookup() callers
Diffstat (limited to 'kernel')
-rw-r--r--kernel/audit.h17
-rw-r--r--kernel/auditsc.c171
2 files changed, 37 insertions, 151 deletions
diff --git a/kernel/audit.h b/kernel/audit.h
index 3cdffad5a1d9..1caa0d345d90 100644
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -24,12 +24,6 @@
#include <linux/skbuff.h>
#include <uapi/linux/mqueue.h>
-/* 0 = no checking
- 1 = put_count checking
- 2 = verbose put_count checking
-*/
-#define AUDIT_DEBUG 0
-
/* AUDIT_NAMES is the number of slots we reserve in the audit_context
* for saving names from getname(). If we get more names we will allocate
* a name dynamically and also add those to the list anchored by names_list. */
@@ -74,9 +68,8 @@ struct audit_cap_data {
};
};
-/* 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).
+/* When fs/namei.c:getname() is called, we store the pointer in name and bump
+ * the refcnt in the associated filename struct.
*
* Further, in fs/namei.c:path_lookup() we store the inode and device.
*/
@@ -86,7 +79,6 @@ struct audit_names {
struct filename *name;
int name_len; /* number of chars to log */
bool hidden; /* don't log this record */
- bool name_put; /* call __putname()? */
unsigned long ino;
dev_t dev;
@@ -208,11 +200,6 @@ struct audit_context {
};
int fds[2];
struct audit_proctitle proctitle;
-
-#if AUDIT_DEBUG
- int put_count;
- int ino_count;
-#endif
};
extern u32 audit_ever_enabled;
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 55f82fce2526..dc4ae70a7413 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -866,33 +866,10 @@ static inline void audit_free_names(struct audit_context *context)
{
struct audit_names *n, *next;
-#if AUDIT_DEBUG == 2
- if (context->put_count + context->ino_count != context->name_count) {
- int i = 0;
-
- pr_err("%s:%d(:%d): major=%d in_syscall=%d"
- " name_count=%d put_count=%d ino_count=%d"
- " [NOT freeing]\n", __FILE__, __LINE__,
- context->serial, context->major, context->in_syscall,
- context->name_count, context->put_count,
- context->ino_count);
- list_for_each_entry(n, &context->names_list, list) {
- pr_err("names[%d] = %p = %s\n", i++, n->name,
- n->name->name ?: "(null)");
- }
- dump_stack();
- return;
- }
-#endif
-#if AUDIT_DEBUG
- context->put_count = 0;
- context->ino_count = 0;
-#endif
-
list_for_each_entry_safe(n, next, &context->names_list, list) {
list_del(&n->list);
- if (n->name && n->name_put)
- final_putname(n->name);
+ if (n->name)
+ putname(n->name);
if (n->should_free)
kfree(n);
}
@@ -1711,9 +1688,6 @@ static struct audit_names *audit_alloc_name(struct audit_context *context,
list_add_tail(&aname->list, &context->names_list);
context->name_count++;
-#if AUDIT_DEBUG
- context->ino_count++;
-#endif
return aname;
}
@@ -1734,8 +1708,10 @@ __audit_reusename(const __user char *uptr)
list_for_each_entry(n, &context->names_list, list) {
if (!n->name)
continue;
- if (n->name->uptr == uptr)
+ if (n->name->uptr == uptr) {
+ n->name->refcnt++;
return n->name;
+ }
}
return NULL;
}
@@ -1752,19 +1728,8 @@ void __audit_getname(struct filename *name)
struct audit_context *context = current->audit_context;
struct audit_names *n;
- if (!context->in_syscall) {
-#if AUDIT_DEBUG == 2
- pr_err("%s:%d(:%d): ignoring getname(%p)\n",
- __FILE__, __LINE__, context->serial, name);
- dump_stack();
-#endif
+ if (!context->in_syscall)
return;
- }
-
-#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)
@@ -1772,56 +1737,13 @@ void __audit_getname(struct filename *name)
n->name = name;
n->name_len = AUDIT_NAME_FULL;
- n->name_put = true;
name->aname = n;
+ name->refcnt++;
if (!context->pwd.dentry)
get_fs_pwd(current->fs, &context->pwd);
}
-/* audit_putname - intercept a putname request
- * @name: name to intercept and delay for putname
- *
- * If we have stored the name from getname in the audit context,
- * then we delay the putname until syscall exit.
- * Called from include/linux/fs.h:putname().
- */
-void audit_putname(struct filename *name)
-{
- struct audit_context *context = current->audit_context;
-
- BUG_ON(!context);
- if (!name->aname || !context->in_syscall) {
-#if AUDIT_DEBUG == 2
- pr_err("%s:%d(:%d): final_putname(%p)\n",
- __FILE__, __LINE__, context->serial, name);
- if (context->name_count) {
- struct audit_names *n;
- int i = 0;
-
- list_for_each_entry(n, &context->names_list, list)
- pr_err("name[%d] = %p = %s\n", i++, n->name,
- n->name->name ?: "(null)");
- }
-#endif
- final_putname(name);
- }
-#if AUDIT_DEBUG
- else {
- ++context->put_count;
- if (context->put_count > context->name_count) {
- pr_err("%s:%d(:%d): major=%d in_syscall=%d putname(%p)"
- " name_count=%d put_count=%d\n",
- __FILE__, __LINE__,
- context->serial, context->major,
- context->in_syscall, name->name,
- context->name_count, context->put_count);
- dump_stack();
- }
- }
-#endif
-}
-
/**
* __audit_inode - store the inode and device from a lookup
* @name: name being audited
@@ -1842,10 +1764,6 @@ void __audit_inode(struct filename *name, const struct dentry *dentry,
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.
@@ -1863,7 +1781,17 @@ void __audit_inode(struct filename *name, const struct dentry *dentry,
}
list_for_each_entry_reverse(n, &context->names_list, list) {
- if (!n->name || strcmp(n->name->name, name->name))
+ if (n->ino) {
+ /* valid inode number, use that for the comparison */
+ if (n->ino != inode->i_ino ||
+ n->dev != inode->i_sb->s_dev)
+ continue;
+ } else if (n->name) {
+ /* inode number has not been set, check the name */
+ if (strcmp(n->name->name, name->name))
+ continue;
+ } else
+ /* no inode and no name (?!) ... this is odd ... */
continue;
/* match the correct record type */
@@ -1882,44 +1810,11 @@ out_alloc:
n = audit_alloc_name(context, AUDIT_TYPE_UNKNOWN);
if (!n)
return;
- /* unfortunately, while we may have a path name to record with the
- * inode, we can't always rely on the string lasting until the end of
- * the syscall so we need to create our own copy, it may fail due to
- * memory allocation issues, but we do our best */
if (name) {
- /* we can't use getname_kernel() due to size limits */
- size_t len = strlen(name->name) + 1;
- struct filename *new = __getname();
-
- if (unlikely(!new))
- goto out;
-
- if (len <= (PATH_MAX - sizeof(*new))) {
- new->name = (char *)(new) + sizeof(*new);
- new->separate = false;
- } else if (len <= PATH_MAX) {
- /* this looks odd, but is due to final_putname() */
- struct filename *new2;
-
- new2 = kmalloc(sizeof(*new2), GFP_KERNEL);
- if (unlikely(!new2)) {
- __putname(new);
- goto out;
- }
- new2->name = (char *)new;
- new2->separate = true;
- new = new2;
- } else {
- /* we should never get here, but let's be safe */
- __putname(new);
- goto out;
- }
- strlcpy((char *)new->name, name->name, len);
- new->uptr = NULL;
- new->aname = n;
- n->name = new;
- n->name_put = true;
+ n->name = name;
+ name->refcnt++;
}
+
out:
if (parent) {
n->name_len = n->name ? parent_len(n->name->name) : AUDIT_NAME_FULL;
@@ -1970,11 +1865,16 @@ void __audit_inode_child(const struct inode *parent,
/* look for a parent entry first */
list_for_each_entry(n, &context->names_list, list) {
- if (!n->name || n->type != AUDIT_TYPE_PARENT)
+ if (!n->name ||
+ (n->type != AUDIT_TYPE_PARENT &&
+ n->type != AUDIT_TYPE_UNKNOWN))
continue;
- if (n->ino == parent->i_ino &&
- !audit_compare_dname_path(dname, n->name->name, n->name_len)) {
+ if (n->ino == parent->i_ino && n->dev == parent->i_sb->s_dev &&
+ !audit_compare_dname_path(dname,
+ n->name->name, n->name_len)) {
+ if (n->type == AUDIT_TYPE_UNKNOWN)
+ n->type = AUDIT_TYPE_PARENT;
found_parent = n;
break;
}
@@ -1983,11 +1883,8 @@ void __audit_inode_child(const struct inode *parent,
/* is there a matching child entry? */
list_for_each_entry(n, &context->names_list, list) {
/* can only match entries that have a name */
- if (!n->name || n->type != type)
- continue;
-
- /* if we found a parent, make sure this one is a child of it */
- if (found_parent && (n->name != found_parent->name))
+ if (!n->name ||
+ (n->type != type && n->type != AUDIT_TYPE_UNKNOWN))
continue;
if (!strcmp(dname, n->name->name) ||
@@ -1995,6 +1892,8 @@ void __audit_inode_child(const struct inode *parent,
found_parent ?
found_parent->name_len :
AUDIT_NAME_FULL)) {
+ if (n->type == AUDIT_TYPE_UNKNOWN)
+ n->type = type;
found_child = n;
break;
}
@@ -2019,10 +1918,10 @@ void __audit_inode_child(const struct inode *parent,
if (found_parent) {
found_child->name = found_parent->name;
found_child->name_len = AUDIT_NAME_FULL;
- /* don't call __putname() */
- found_child->name_put = false;
+ found_child->name->refcnt++;
}
}
+
if (inode)
audit_copy_inode(found_child, dentry, inode);
else