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authorNeil Brown <neilb@suse.de>2006-09-09 17:44:45 +0200
committerAdrian Bunk <bunk@stusta.de>2006-09-09 17:44:45 +0200
commit226e6ea4df373b5f805e5acc81e2910d716ec77d (patch)
tree9a413048671cc57e3e1b4b0aa51d20cfc97553c7
parentaa95228d02569fe57affd0d5b966b2d547536571 (diff)
Have ext2 reject file handles with bad inode numbers early.
This prevents bad inode numbers from triggering errors in ext2_get_inode. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
-rw-r--r--fs/ext2/super.c41
1 files changed, 41 insertions, 0 deletions
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index cb6f9bd658de..a8fbef73ea99 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -253,6 +253,46 @@ static struct super_operations ext2_sops = {
#endif
};
+static struct dentry *ext2_get_dentry(struct super_block *sb, void *vobjp)
+{
+ __u32 *objp = vobjp;
+ unsigned long ino = objp[0];
+ __u32 generation = objp[1];
+ struct inode *inode;
+ struct dentry *result;
+
+ if (ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb))
+ return ERR_PTR(-ESTALE);
+ if (ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
+ return ERR_PTR(-ESTALE);
+
+ /* iget isn't really right if the inode is currently unallocated!!
+ * ext2_read_inode currently does appropriate checks, but
+ * it might be "neater" to call ext2_get_inode first and check
+ * if the inode is valid.....
+ */
+ inode = iget(sb, ino);
+ if (inode == NULL)
+ return ERR_PTR(-ENOMEM);
+ if (is_bad_inode(inode)
+ || (generation && inode->i_generation != generation)
+ ) {
+ /* we didn't find the right inode.. */
+ iput(inode);
+ return ERR_PTR(-ESTALE);
+ }
+ /* now to find a dentry.
+ * If possible, get a well-connected one
+ */
+ result = d_alloc_anon(inode);
+ if (!result) {
+ iput(inode);
+ return ERR_PTR(-ENOMEM);
+ }
+ return result;
+}
+
+
/* Yes, most of these are left as NULL!!
* A NULL value implies the default, which works with ext2-like file
* systems, but can be improved upon.
@@ -261,6 +301,7 @@ static struct super_operations ext2_sops = {
struct dentry *ext2_get_parent(struct dentry *child);
static struct export_operations ext2_export_ops = {
.get_parent = ext2_get_parent,
+ .get_dentry = ext2_get_dentry,
};
static unsigned long get_sb_block(void **data)