From fdb36673a9d6accf93b11e7eff3a7e34cd284616 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Sat, 16 Sep 2006 12:15:38 -0700 Subject: [PATCH] [PATCH] knfsd: Make ext3 reject filehandles referring to invalid inode number Inodes earlier than the 'first' inode (e.g. journal, resize) should be rejected early - except the root inode. Also inode numbers that are too big should be rejected early. [akpm@osdl.org: cleanup] Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ext3/super.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) diff --git a/fs/ext3/super.c b/fs/ext3/super.c index 813d589cc6c0..3559086eee5f 100644 --- a/fs/ext3/super.c +++ b/fs/ext3/super.c @@ -554,6 +554,47 @@ static int ext3_show_options(struct seq_file *seq, struct vfsmount *vfs) return 0; } + +static struct dentry *ext3_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 < EXT3_FIRST_INO(sb) && ino != EXT3_ROOT_INO) + return ERR_PTR(-ESTALE); + if (ino > le32_to_cpu(EXT3_SB(sb)->s_es->s_inodes_count)) + return ERR_PTR(-ESTALE); + + /* iget isn't really right if the inode is currently unallocated!! + * + * ext3_read_inode will return a bad_inode if the inode had been + * deleted, so we should be safe. + * + * Currently we don't know the generation for parent directory, so + * a generation of 0 means "accept any" + */ + inode = iget(sb, ino); + if (inode == NULL) + return ERR_PTR(-ENOMEM); + if (is_bad_inode(inode) || + (generation && inode->i_generation != generation)) { + 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; +} + #ifdef CONFIG_QUOTA #define QTYPE2NAME(t) ((t)==USRQUOTA?"user":"group") #define QTYPE2MOPT(on, t) ((t)==USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA)) @@ -622,6 +663,7 @@ static struct super_operations ext3_sops = { static struct export_operations ext3_export_ops = { .get_parent = ext3_get_parent, + .get_dentry = ext3_get_dentry, }; enum { -- 2.20.1