From cbca4f2e2cba4f8d4482d6ddd21199b71c2476b0 Mon Sep 17 00:00:00 2001 From: Eric Sandeen Date: Wed, 30 Aug 2006 18:01:00 +0200 Subject: Have ext3 reject file handles with bad inode numbers early blatantly ripped off from Neil Brown's ext2 patch. Signed-off-by: Eric Sandeen Acked-by: "Theodore Ts'o" Signed-off-by: Adrian Bunk --- fs/ext3/super.c | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) (limited to 'fs') diff --git a/fs/ext3/super.c b/fs/ext3/super.c index 56bf76586019..7aac511d7114 100644 --- a/fs/ext3/super.c +++ b/fs/ext3/super.c @@ -619,8 +619,48 @@ static struct super_operations ext3_sops = { #endif }; +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_ROOT_INO && ino < EXT3_FIRST_INO(sb)) + 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 currently does appropriate checks, but + * it might be "neater" to call ext3_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; +} + static struct export_operations ext3_export_ops = { .get_parent = ext3_get_parent, + .get_dentry = ext3_get_dentry, }; enum { -- cgit v1.2.3